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Attribute error in python won't go away Question: Why do I keep getting AttributeError: 'dict_keys' object has no attribute 'sort' or my code? How can I fix this? import string infile = open('alice_in_wonderland.txt', 'r') text = infile.readlines() counts = {} for line in text: for word in line: counts[word] = counts.get (word, 0) +1 ''' if word != " ": if word != ".": ''' word_keys = counts.keys() word_keys.sort() infile.close() outfile = open("alice_words.txt", 'w') outfile.write("Word \t \t Count \n") outfile.write("======================= \n") for word in word_keys: outfile.write("%-12s%d\n" % (word.lower(), counts[word])) outfile.close() I'm not sure what else to do. Answer: To produce a sorted list of keys, use: word_keys = sorted(counts) instead. This works in both Python 2 and 3. In Python 3 `dict.keys()` does not return a list object, but a [dictionary view object](https://docs.python.org/3/library/stdtypes.html#dictionary-view- objects). You could call `list()` on that object, but `sorted()` is much more direct and saves you two additional calls. I see that you appear to count words in a file; if so, you are instead counting _characters_ , not words; `for word in line:` iterates over a string, so `word` is assigned individual characters from the line. You should be using [`collections.Counter()`](https://docs.python.org/2/library/collections.html#collections.Counter) instead: from collections import Counter counts = Counter with open('alice_in_wonderland.txt') as infile: for line in infile: # assumption: words are whitespace separated counts.update(w for w in line.split()) with open("alice_words.txt", 'w') as outfile: outfile.write("Word \t \t Count \n") outfile.write("======================= \n") for word, count in counts.most_common(): outfile.write("%-12s%d\n" % (word.lower(), counts[word])) This code uses the file objects as context managers (with the `with` statement) to have them closed automatically. The `Counter.most_common()` method takes care of the sorting for us, not by key but by word count.
Python create save button that saves an edited version to the same file(not save as) Question: This is a simple notepad program that i am currently writing. Most things are working but cannot get the save to work. Where i have defined save i don't know how to create the save function(not save as). NOT THE FULL CODE from tkinter import * from tkinter.messagebox import * from tkinter.filedialog import * from tkinter.font import * import sys, time, sched, math class Format: def __init__(self, notepad): print("Font") class ZPad: def __init__(self): self.root = Tk() self.root.title("ZPad") self.root.wm_iconbitmap('Notepad.ico') self.scrollbar = Scrollbar(self.root) self.scrollbar.pack(side=RIGHT, fill=Y) self.textbox = Text(self.root, yscrollcommand=self.scrollbar.set, undo=TRUE) self.textbox.pack(side=LEFT, fill=BOTH, expand=YES) #Menu Bar self.menubar = Menu(self.root) self.filemenu = Menu(self.menubar, tearoff=0) self.filemenu.add_command(label="New", command=self.New, accelerator="Ctrl+N") self.filemenu.add_command(label="Open...", command=self.open, accelerator="Ctrl+O") self.filemenu.add_command(label="Save", command=self.Save, accelerator="Ctrl+S") self.filemenu.add_command(label="Save as...", command=self.Save_as, accelerator="Ctrl+Shift+S") self.filemenu.add_separator() self.filemenu.add_command(label="Exit", command=self.quit, accelerator="Ctrl+Q") self.menubar.add_cascade(label="File", menu=self.filemenu) self.editmenu = Menu(self.menubar, tearoff=0) self.editmenu.add_command(label="Undo", command=self.Undo, accelerator="Ctrl+Z") self.editmenu.add_command(label="Redo", command=self.Redo, accelerator="Ctrl+Y") self.editmenu.add_separator() self.editmenu.add_command(label="Cut", command=self.Cut, accelerator="Ctrl+X") self.editmenu.add_command(label="Copy", command=self.Copy, accelerator="Ctrl+C") self.editmenu.add_command(label="Paste", command=self.Paste, accelerator="Ctrl+P") self.editmenu.add_command(label="Clear All", command=self.Clear_All, accelerator="Ctrl+Shift+A") self.editmenu.add_separator() self.editmenu.add_command(label="Format", command=self.options, accelerator="Ctrl+T") self.menubar.add_cascade(label="Edit", menu=self.editmenu) self.helpmenu = Menu(self.menubar, tearoff=0) self.helpmenu.add_command(label="About...", command=self.About) self.menubar.add_cascade(label="Help", menu=self.helpmenu) self.root.config(menu=self.menubar) self.root.mainloop() def Save(self): print("Save") def Save_as(self): global file file = tkinter.filedialog.asksaveasfile(mode='w', defaultextension=".z", filetypes = ( ("ztext file", "*.z"),("zytext", "*.zy") ) ) if file is None: return else: print(file) textoutput = self.textbox.get(0.0, END) file.write(textoutput.rstrip()) file.write("\n") notepad = ZPad() I am using python 3.4 in windows 8.1. Thanks. Answer: Here's a quick example of a save and save as function, with comments: def save(self): contents = self.textbox.get(1.0,"end-1c") #store the contents of the text widget in a str try: #this try/except block checks to with open(self.f, 'w') as outputFile: #see if the str containing the output outputFile.write(contents) #file (self.f) exists, and we can write to it, except AttributeError: #and if it doesn't, self.save_as() #call save_as def save_as(self): contents = self.textbox.get(1.0,"end-1c") self.f = tkFileDialog.asksaveasfilename( #this will make the file path a string defaultextension=".z", #so it's easier to check if it exists filetypes = (("ztext file", "*.z"), #in the save function ("zytext", "*.zy"))) with open(self.f, 'w') as outputFile: outputFile.write(contents) There are other ways to do this, but this will work in a pinch. Just think about what the `save` function needs: text to save and a file to save in, and go from there.
Bigquery streaming API timeout error Question: We're using bigquery streaming API. All went well until recently (no code change) - In the last few hours we get many errors like: > "The API call urlfetch.Fetch() took too long to respond and was cancelled. > Traceback (most recent call last): File "/base/data/home/runtimes/python27" or > "Deadline exceeded while waiting for HTTP response from URL" The insert call is done on a python deferred process and is retried again after a wait. Questions: * How can we check if it's our internal issue or a general problem with big query? * Can we increase the 5000 timeout? Answer: Are you running in appengine? If so, you can do this: from google.appengine.api import urlfetch urlfetch.set_default_fetch_deadline(60) That said, streaming ingestion shouldn't be anywhere close to the default 5 second error. There was a networking configuration issue with streaming ingestion, it should be resolved now. Are you still seeing the issues?
python requests read from file status_code wrong Question: trying to read a file with urls and extract the status_code with python requests module. this does not work, or gives me a wrong status code: import requests f = open('urls.txt','r') for line in f: r = requests.head(line) print r.status_code if r.status_code == requests.codes.ok: print "ok"; but if I do it manually (without file read) it works. import requests r = requests.head('https://encrypted.google.com/') print r.status_code if r.status_code == requests.codes.ok: print "ok"; Answer: Do a `line.strip()` before making the `head` call. There is a possibility that the carriage return and/or line feed characters are part of the line you just read. Like this: for line in f: r = requests.head(line.strip()) print r.status_code
python maya - Select children 'nurbs' then hides key Question: The script below selects all the child nurbCurves of the selected object. The issue I'm having is that after running the script, none of the keys from the children nodes appear in the timeline. Why is that? How can I correct this? To test the script. Create a few nurb curve controls and animate the position. Then parent them together so their parent is the same master control. Then select the main control and run the script. import maya.cmds as cmds # Get selected objects curSel = maya.cmds.ls(sl=True) # Or, you can also specify a type in the listRelatives command nurbsNodes = maya.cmds.listRelatives(curSel, allDescendents=True, noIntermediate=True, fullPath=True, type="nurbsCurve", path=True) cmds.select(nurbsNodes) Answer: You are selecting the `nurbsCurve` _shapes_ , but your animation is on the _transform_ # list the shape nodes nurbsShapes = maya.cmds.listRelatives(curSel, allDescendents=True, noIntermediate=True, fullPath=True, type="nurbsCurve", path=True) # list the transform nodes to each shape node nurbsTransforms = maya.cmds.listRelatives(nurbsShapes, type='transform', parent=True) # select the transform nodes cmds.select(nurbsTransforms)
Python: Reducing a List in a Dictionary Question: I'm hoping this will be easy. I have a dictionary: { 'key1': 'value1', 'key2': 'value2', 'key3': 'value3' }, { 'key1': 'value4', 'key2': 'value5', 'key3': 'value6' }, How can I reduce this to be the following: { 'key1': ['value1', 'value4'], 'key2': ['value2', 'value5'], 'key3': ['value3', 'value6'] } Many thanks! Answer: Like this: from collections import defaultdict d1 = { 'key1': 'value1', 'key2': 'value2', 'key3': 'value3' } d2 = { 'key1': 'value4', 'key2': 'value5', 'key3': 'value6' } dout = defaultdict(list) for item in d1: dout[item].append(d1[item]) for item in d2: dout[item].append(d2[item]) print dout
np complete algorithm in python [solved] Question: This question is closed. All information about this question will be uploaded in a week. I am still trying to figure out the full details. Still testing it as a module. n is the number of elements and formula is a the clauses this is an np complete algorithm. the code tries to figure out for any permutations of n could satisfy if the formula is correct. booleanValues = [True,False] * n allorderings = set(itertools.permutations(booleanValues, n)) #create possible combinations of variables that can check if formula is satisfiable or not print(allorderings) for potential in allorderings: l = [] #boolean value for each variable / different combination for each iteration for i in potential: l.append(i) #possible = [False]*n aclause = [] for clause in formula: something = [] #clause is [1,2,3] for item in clause: if item > 0: something.append(l[item-1]) else: item = item * -1 x = l[item-1] if x == True: x = False else: x = True something.append(x) counter = 0 cal = False for thingsinclause in something: if counter == 0: cal = thingsinclause counter = counter + 1 else: cal = cal and thingsinclause counter = counter + 1 aclause.append(cal) counter2 = 0 formcheck = False for checkformula in aclause: if counter2 == 0: formcheck = checkformula counter2 = counter2 + 1 else: formcheck = formcheck or checkformula print("this combination works", checkformula) Answer: Here is a corrected version: import itertools n = 4 formula = [[1, -2, 3], [-1, 3], [-3], [2, 3]] allorderings = itertools.product ([False, True], repeat = n) for potential in allorderings: print ("Initial values:", potential) allclauses = [] for clause in formula: curclause = [] for item in clause: x = potential[abs (item) - 1] curclause.append (x if item > 0 else not x) cal = any (curclause) allclauses.append (cal) print ("Clauses:", allclauses) formcheck = all (allclauses) print ("This combination works:", formcheck) Points to consider: 1. Instead of introducing some complex -- and also wrong -- logic to find the conjunction and disjunction, you can use [`any`](https://docs.python.org/2/library/functions.html#any) and [`all`](https://docs.python.org/2/library/functions.html#all). That's cleaner and less prone to bugs. 2. The natural object to loop over is `itertools.product([False, True], repeat = n)`, that is, the set `[False, True]` of possible boolean values raised to the power of `n`. In other words, the [Cartesian product](http://en.wikipedia.org/wiki/Cartesian_product) of `n` copies of `[False, True]`. [Here](https://docs.python.org/2.7/library/itertools.html#itertools.product) is the documentation for itertools.product. 3. I introduced a bit more output to see how things are going. Here is the output I get with Python3 (Python2 adds parentheses but prints essentially the same): * * * Initial values: (False, False, False, False) Clauses: [True, True, True, False] This combination works: False Initial values: (False, False, False, True) Clauses: [True, True, True, False] This combination works: False Initial values: (False, False, True, False) Clauses: [True, True, False, True] This combination works: False Initial values: (False, False, True, True) Clauses: [True, True, False, True] This combination works: False Initial values: (False, True, False, False) Clauses: [False, True, True, True] This combination works: False Initial values: (False, True, False, True) Clauses: [False, True, True, True] This combination works: False Initial values: (False, True, True, False) Clauses: [True, True, False, True] This combination works: False Initial values: (False, True, True, True) Clauses: [True, True, False, True] This combination works: False Initial values: (True, False, False, False) Clauses: [True, False, True, False] This combination works: False Initial values: (True, False, False, True) Clauses: [True, False, True, False] This combination works: False Initial values: (True, False, True, False) Clauses: [True, True, False, True] This combination works: False Initial values: (True, False, True, True) Clauses: [True, True, False, True] This combination works: False Initial values: (True, True, False, False) Clauses: [True, False, True, True] This combination works: False Initial values: (True, True, False, True) Clauses: [True, False, True, True] This combination works: False Initial values: (True, True, True, False) Clauses: [True, True, False, True] This combination works: False Initial values: (True, True, True, True) Clauses: [True, True, False, True] This combination works: False
python telnet server crash Question: Whenever my client connect to my server via telnet telnet myip 43 When the client hits ctrl+c on his own machine continuously it causes the telnet server to crash... how can this be stopped ? Also are there any chances by which my server can be attacked by a buffer overflow? This is my script(very basic script it is) #!/usr/bin/env python import sys import socket import urllib2 def main(): s = socket.socket() # Create a socket object host = '' BUFFER_SIZE = 2048 port = 43 # Reserve a port for your service. s.bind((host, port)) # Bind to the port s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) s.listen(120) # Now wait for client connection. while True: data = '' print 'waiting for connection...' c, addr = s.accept() # Establish connection with client. print 'Got connection from', addr data = c.recv(BUFFER_SIZE) print 'requested website: '+data print x c.send(x) c.close() # Close the connection if __name__ == '__main__': main() Answer: try [this](http://stackoverflow.com/questions/295135/turn-a-string-into-a- valid-filename-in-python): import string valid_chars = "-_.() %s%s" % (string.ascii_letters, string.digits) [...] data = c.recv(BUFFER_SIZE) data=''.join(c for c in data if c in valid_chars) print 'requested website: '+data if len(data)>0: try: urllib2.urlopen('localhost:2020/?id='+data ).read() print x c.send(x) except: pass c.close() # Close the connection Edit `valid_chars` to only allow characters allowed for your id argument.
How retrieve from Python win32evtlog rest of info? Question: Using win32evtlog I can get next info: events = win32evtlog.ReadEventLog(loghandle, flags, 0) while events: for event in events: print 'Event Category:', event.EventCategory print 'Time Generated:', event.TimeGenerated print 'Source Name:', event.SourceName print 'Event ID:', event.EventID print 'Event Type:', event.EventType data = event.StringInserts if data: print 'Event Data:' for msg in data: print msg events = win32evtlog.ReadEventLog(loghandle, flags, 0) But if we look at event structure: <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event"> - <System> <Provider Name="PRNAME" /> <EventID Qualifiers="0">18</EventID> <Level>0</Level> <Task>0</Task> <Keywords>0xa0000000000000</Keywords> <TimeCreated SystemTime="2012-04-03T05:30:02.000000000Z" /> <EventRecordID>2387524</EventRecordID> <Channel>PRNAME</Channel> <Computer>A00001</Computer> <Security /> </System> - <EventData> <Data>tst</Data> <Binary>01020304</Binary> </EventData> </Event> We can find there additional info: * Channel name - that is different from Provider name * EventRecordId * Computer * Binary and other. How to get them? I especially need Binary and EventRecordId, but I guess there have to be way to get all data from event log. Answer: If you don't mind to use BeautifulSoup over the xml formatted data, then here is an example from bs4 import BeautifulSoup soup = BeautifulSoup(event_log_as_xml) print soup.find("channel").text print soup.find("eventrecordid").text print soup.find("computer").text print soup.find("binary").text
python web scraping of a dynamically loading page Question: Let's say i want to scrape this page: <https://twitter.com/nfl> from bs4 import BeautifulSoup import requests page = 'https://twitter.com/nfl' r = requests.get(page) soup = BeautifulSoup(r.text) print soup The more i scroll down on the page, the more results show up. But this above request only gives me the initial load. How do i get all the information of the page as if I were to manually scroll down? Answer: First parse the `data-max-id="451819302057164799"` value from the html source. Then using the id `451819302057164799` construct an url like below: `https://twitter.com/i/profiles/show/nfl/timeline?include_available_features=1&include_entities=1&max_id=451819302057164799` Now get the html source of the link and parse using `simplejson` or any other json library. Remember, the next page load(when you scroll down) is available from the value `"max_id":"451369755908530175"` in that json.
Sending RabbitMQ messages via websockets Question: Looking for some code samples to solve this problem :- Would like to write some code (Python or Javascript) that would act as a subscriber to a RabbitMQ queue so that on receiving a message it would broadcast the message via websockets to any connected client. I've looked at Autobahn and node.js (using "[amqp](https://github.com/postwait/node-amqp)" and "[ws](https://github.com/einaros/ws)" ) but cannot get things to work as needed. Here's the server code in javascript using node.js:- var amqp = require('amqp'); var WebSocketServer = require('ws').Server var connection = amqp.createConnection({host: 'localhost'}); var wss = new WebSocketServer({port:8000}); wss.on('connection',function(ws){ ws.on('open', function() { console.log('connected'); ws.send(Date.now().toString()); }); ws.on('message',function(message){ console.log('Received: %s',message); ws.send(Date.now().toString()); }); }); connection.on('ready', function(){ connection.queue('MYQUEUE', {durable:true,autoDelete:false},function(queue){ console.log(' [*] Waiting for messages. To exit press CTRL+C') queue.subscribe(function(msg){ console.log(" [x] Received from MYQUEUE %s",msg.data.toString('utf-8')); payload = msg.data.toString('utf-8'); // HOW DOES THIS NOW GET SENT VIA WEBSOCKETS ?? }); }); }); Using this code, I can successfully subscribe to a queue in Rabbit and receive any messages that are sent to the queue. Similarly, I can connect a websocket client (e.g. a browser) to the server and send/receive messages. BUT ... how can I send the payload of the Rabbit queue message as a websocket message at the point indicated ("HOW DOES THIS NOW GET SENT VIA WEBSOCKETS") ? I think it's something to do with being stuck in the wrong callback or they need to be nested somehow ...? Alternatively, if this can be done easier in Python (via Autobahn and pika) that would be great. Thanks ! Answer: One way to implement your system is use python with [tornado](http://www.tornadoweb.org). Here the server: import tornado.ioloop import tornado.web import tornado.websocket import os import pika from threading import Thread clients = [] def threaded_rmq(): connection = pika.BlockingConnection(pika.ConnectionParameters("localhost")); print 'Connected:localhost' channel = connection.channel() channel.queue_declare(queue="my_queue") print 'Consumer ready, on my_queue' channel.basic_consume(consumer_callback, queue="my_queue", no_ack=True) channel.start_consuming() def consumer_callback(ch, method, properties, body): print " [x] Received %r" % (body,) for itm in clients: itm.write_message(body) class SocketHandler(tornado.websocket.WebSocketHandler): def open(self): print "WebSocket opened" clients.append(self) def on_message(self, message): self.write_message(u"You said: " + message) def on_close(self): print "WebSocket closed" clients.remove(self) class MainHandler(tornado.web.RequestHandler): def get(self): print "get page" self.render("websocket.html") application = tornado.web.Application([ (r'/ws', SocketHandler), (r"/", MainHandler), ]) if __name__ == "__main__": thread = Thread(target = threaded_rmq) thread.start() application.listen(8889) tornado.ioloop.IOLoop.instance().start() and here the html page: <html> <head> <script src="//code.jquery.com/jquery-1.11.0.min.js"></script> <script> $(document).ready(function() { var ws; if ('WebSocket' in window) { ws = new WebSocket('ws://localhost:8889/ws'); } else if ('MozWebSocket' in window) { ws = new MozWebSocket('ws://localhost:8889/ws'); } else { alert("<tr><td> your browser doesn't support web socket </td></tr>"); return; } ws.onopen = function(evt) { alert("Connection open ...")}; ws.onmessage = function(evt){ alert(evt.data); }; function closeConnect(){ ws.close(); } }); </script> </head> <html> So when you publish a message to "my_queue" the message is redirects to all web page connected. I hope it can be useful EDIT** Here <https://github.com/Gsantomaggio/rabbitmqexample> you can find the complete example
I'm receiving the error 'except MySQLdb.error, e' Syntax Error - invalid syntax when trying to write my scrapy spider to mysql, Question: Here is my pipelines.py and I'm receiving an error on line 18. import sys;sys.path.append("/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages") import MySQLdb import hashlib from scrapy.exceptions import DropItem from scrapy.http import Request class TestPipeline(object): def __init__(self): self.conn = MySQLdb.connect(user='test', passwd='password', db='c1024403', host='ephesus.cs.cf.ac.uk', charset='utf8', use_unicode=True) self.cursor = self.conn.cursor() def process_item(self, item, spider): try: self.cursor.execute("""INSERT INTO test (test1, test2) VALUES (%s, %s)""", (item['Country'], item['Qualification'])) self.conn.commit() except MySQLdb.Error, e: print 'Error %d: %s' % (e.args[0], e.args[1]) sys.exit(1) return item Heres the error - File "project\pipelines.py", line 18 except MySQLdb.Error, e: ^ SyntaxError: invalid syntax I've installed mysql-python and visual c++ 2008 express, I don't understand what the error means as I can't find anything about it anywhere else on the internet. Answer: You are running your code with `Python 3.x`, but your code scheme for `try.. except` section is for `Python 2.X`. If you want to run your code with `Python 3.x`, then change this line: except MySQLdb.Error, e: To: except MySQLdb.Error as e: And if you want this section of code works with `Python 2.x` and also `Python 3.x`, then change it to: except MySQLdb.Error: e = sys.exc_info()[1] Read [more](https://docs.python.org/3/howto/pyporting.html#capturing-the- currently-raised-exception). But according to your `print` statement, you write your script for `Python 2.x`, so it's better to run your code with `Python 2.x`, instead of `Python 3.x` Also this `sys.path.append("../python2.7/site-packages")` line is strange in first line of your script. Also your indention of your first code that you pasted was wrong, and i think your are still using that, please use current edited version that is now in your question.
Python Can't Find Modules Question: I'm running a python script which resizes and converts images to JPG and an RGB. This script worked perfectly until I upgraded my computers HD and moved everything over from my Time Machine backup. Now when I try to run the script it can't find any modules. Specifically the Image module (I use Pillow). Traceback (most recent call last): File "processImgs.py", line 1, in <module> import os, sys, argparse, shutil, imgFunctions File "/web/script/python/img_processing/imgFunctions.py", line 1, in <module> import os, sys, Image, shutil, re ImportError: No module named Image I am using Homebrew to manage my modules, and "brew list" outputs the following: freetype graphicsmagick libpng libtool little-cms2 openssl pkg-config readline webp gdbm jpeg libtiff little-cms openjpeg pillow python sqlite If i run "pip list" I get: Pillow (2.3.0) pip (1.5.4) setuptools (2.2) wsgiref (0.1.2) If i run "help(modules)" in python, the Image module isn't listed. Answer: Could be your python path isn't set up correctly after the move. [see here](https://github.com/Homebrew/homebrew/wiki/Homebrew-and-Python) for the homebrew/python docs page and it seems that a reinstall of homebrew may fix it.
Jython output formats, adding symbol at N:th character Question: I have a problem that probably is very easy to solve. I have a script that takes numbers from various places does math with them and then prints the results as strings. This is a sample type("c", KEY_CTRL) LeInput = Env.getClipboard().strip() #Takes stuff from clipboard LeInput = LeInput.replace("-","") #Quick replace Variable = int(LeInput) + 5 #Simple math operation StringOut = str(Variable) #Converts it to string popup(StringOut) #shows result for the amazed user But what I want to do is to add the "-" signs again as per XXXX-XX-XX but I have no idea on how to do this with Regex etc. The only solution I have is dividing it by 10^N to split it into smaller and smaller integers. As an example: int 543442/100 = 5434 giving the first string the number 5434, and then repeat process until i have split it enough times to get my 5434-42 or whatever. **So how do I insert any symbol at the N:th character?** OK, so here is the Jython solution based on the answer from Tenub import re strOut = re.sub(r'^(\d{4})(.{2})(.{2})', r'\1-\2-\3', strIn) This can be worth noting when doing Regex with Jython: > The solution is to use Python’s raw string notation for regular expression > patterns; backslashes are not handled in any special way in a string literal > prefixed with 'r'. **So r"\n" is a two- character** *_string containing '\' > and 'n', while "\n" is a one-character string_ * **containing a newline. > Usually patterns will be expressed in Python** *_code using this raw string > notation._ * Here is a working example <http://regex101.com/r/oN2wF1> Answer: In that case you could do a replace with the following: (\d{4})(\d{2})(\d+) to $1-$2-$3
Doctest and Decorators in Python Question: I was trying to use Python decorator to catch exceptions and log the exceptions. import os.path import shutil class log(object): def __init__(self, f): print "Inside __init__()" self.f = f def __call__(self, *args): print "Inside __call__()" try: self.f(*args) except Exception: print "Sorry" @log def testit(a, b, c): print a,b,c raise RuntimeError() if __name__ == "__main__": testit(1,2,3) It works fine Desktop> python deco.py Inside __init__() Inside __call__() 1 2 3 Sorry The issue is that when I tried to use for testing with doctest @log def testit(a, b, c): """ >>> testit(1,2,3) """ print a,b,c raise RuntimeError() if __name__ == "__main__": import doctest doctest.testmod() nothing seems to be happening. Desktop> python deco2.py Inside __init__() What's wrong with this? Answer: The decorated function (which is actually a class instance) doesn't get the `__doc__` attribute of the original function (which is what `doctest` parses). You _could_ just copy `__doc__` over to the class instance, but ... Honestly, I don't really see the need for a class at all here -- you'd probably be better just using `functools.wraps` import functools def log(func): @functools.wraps(func) def wrapper(*args): try: return func(*args) except Exception: print "sorry" return wrapper
convert a code from java into python Question: Now I am trying to change a program from Java into Python, when I finally fix three problems on my code and I run it. Then shows me this Error. Traceback (most recent call last): File "serial.py", line 4, in <module> import serial File "/home/pi/serial.py", line , in <module> port=serial.Serial( AttributeError:'module' object has no attribute 'Serial' How can I fix it? If you need the source code and What were the problems that I had to fix, let me know. Please help me about it. Answer: I think import serial is wrong. Did you try:- from serial import serial <http://pyserial.sourceforge.net/shortintro.html>
How to create a matrix? (Python) Question: I want to create a 2x3 matrix. (2 rows, 3 columns) When I run my code, I get the matrix in parentheses, which is incorrect. def fill_matrix(numrows, numcols, val): matrix = [[val for i in range(numrows)] for j in range(numcols)] return (numrows, numcols, val) If I choose to create a 2x2 matrix and fill all holes with 1, I'm supposed to get this: [[1, 1], [1, 1]] But I get this instead: (2, 2, 1) Answer: Your `fill_matrix` function returns the tuple `(numrows, numcols, val)`, which is why you're getting `(2,2,1)`. You're not returning the matrix at all. You could try: def fill_matrix(numrows, numcols, val): return [[val for i in range(numrows)] for j in range(numcols)] to just return the matrix itself. If you're working with matricies you might also consider using [numpy](http://www.numpy.org/) and doing: import numpy as np np.ones((2,2)) or: def fill_matrix(numrows, numcols, val): return np.ones((numrows, numcols)) * val
Converting data into dictionary of Dictionaries in python Question: I am reading a file in python using a key value pair, for example Mac:aaaa IP:bbbbb Name:dddd Mac:wwwww IP:fffff Name:sssss Mac:hhhh IP:ddd Name:fff so, my query is, I need to build a dictionary of dictionaries for the above data so as to format it as json. Answer: I assume you mean a list of dictionaries, not a dictionary of dictionaries from operator import methodcaller fdata = open("data.txt").read().split() split2 = methodcaller("split",":") print map(dict, zip(*[iter(map(split2, fdata))]*3)) is a fun way to do it ;) however if you did want a dictionary of dictionaries as your title suggests you can simply dict(enumerate(map(dict, zip(*[iter(map(split2, fdata.split()))]*3)))) [edited to be more pep-8 compliant :P ]
How do I fix the deprecation warning that comes with pylab.pause? Question: A short python program to demonstrate a bug I keep running into: import pylab pylab.ion() pylab.title('doom') pylab.pause(0) If I run it, it works fine, but I get this warning: /usr/lib/pymodules/python2.7/matplotlib/backend_bases.py:2280: MatplotlibDeprecationWarning: Using default event loop until function specific to this GUI is implemented If I remove the pause line, then I don't get the warning, but my plot ceases to exist as soon as the program finishes. I should like an elegant way to get the behaviour without the warning. Can anyone help? Answer: It looks like [waitforbuttonpress](http://matplotlib.org/api/pyplot_api.html#matplotlib.pyplot.waitforbuttonpress) should do what you want. Just replce the `pause` with `pylab.waitforbuttonpress(timeout=-1)`.
Is flush method missing in couchbase python client? Question: I did not find the flush button for bucket in couchbase admin UI at port 8091 .May be because of this <http://www.couchbase.com/issues/browse/MB-5351> . Then I saw this [How to delete all items in the bucket?](http://stackoverflow.com/questions/15966769/how-to-delete-all-items- in-the-bucket) so I wanted to do flush in python client . import sys from couchbase import Couchbase from couchbase.exceptions import CouchbaseError try: client = Couchbase.connect(bucket='production',host='localhost',port=8091) except CouchbaseError as e: print " Sorry , we could not create connection to bucket specified , due to " , e else : print "Successfully made the connection to bucket " Here client i did not find a method to flush . I tried intellisense in IDE . Please guide me to flush the bucket via python client . Answer: It appears that the couchbase python SDK does not currently provide a flush() method. But since the flush method is provided through the couchbase REST API you may use it to flush your bucket. Reference: Couchbase REST API, Buckets API - <http://docs.couchbase.com/admin/admin/REST/rest-bucket-intro.html> The python SDK provides an **Admin** object which you can use to perform your administrator tasks using REST using its **http_request** method. source code: <https://github.com/couchbase/couchbase-python- client/blob/master/couchbase/admin.py> description of the Admin class (from source): > An administrative connection to a Couchbase cluster. > > > With this object, you can do things which affect the cluster, such as > modifying buckets, allocating nodes, or retrieving information about > the cluster. > > This object should **not** be used to perform Key/Value operations. The > :class:`couchbase.bucket.Bucket` is used for that. > Admin.http_request method description (from source): > > Perform an administrative HTTP request. This request is sent out to > the administrative API interface (i.e. the "Management/REST API") > of the cluster. > > See <LINK?> for a list of available comments. > > Note that this is a fairly low level function. This class will with > time contain more and more wrapper methods for common tasks such > as bucket creation or node allocation, and this method should > mostly be used if a wrapper is not available. > * * * Example: First make sure that the Flush option is enabled for your bucket. I created a test bucket named "default" for the example and created 2 documents within the bucket. import sys from couchbase import Couchbase from couchbase.exceptions import CouchbaseError #import Admin module from couchbase.admin import Admin #make an administrative connection using Admin object try: admin = Admin(username='Administrator',password='password',host='localhost',port=8091) except CouchbaseError as e: print " Sorry , we could not create admin connection , due to " , e else : print "Successfully made an admin connection " #retrieve bucket information for bucket named "default" # "default" is just the name of the bucket I set up for trying this out try: htres = admin.http_request("/pools/default/buckets/default") except Exception as e: print "ERROR: ", e sys.exit() #print the current number of items in the "default" bucket # "default" is just the name of the bucket I set up for trying this out print "# of items before flush: ", htres.value['basicStats']['itemCount'] #flush bucket try: #the bucket information request returned the path to the REST flush method for this bucket # the flush method requires a POST request htres = admin.http_request(htres.value['controllers']['flush'],"POST") except Exception as e: print "ERROR: ", e sys.exit() #re-retrieve bucket information for bucket named "default" try: htres = admin.http_request("/pools/default/buckets/default") except Exception as e: print "ERROR: ", e sys.exit() #print the number of items in the "default" bucket (after flush) print "# of items after flush: ", htres.value['basicStats']['itemCount'] result: > > Successfully made an admin connection > # of items before flush: 2 > # of items after flush: 0 >
display pdf with python using pdfviewer Question: I'm trying to display a pdf using pdfviewer lib from wx but I can't find the module. I already have the wxPython installed is it deprecated ? I'm following this tutorial : <http://wxpython.org/Phoenix/docs/html/lib.pdfviewer.html#module- lib.pdfviewer> And I'm getting : `ImportError: No module named pdfviewer` Answer: I am not allowed to write comments, so sorry for asking this question as my answer, but have you seen the comment on the website? > The viewer uses pyPDF2 or pyPdf, if neither of them are installed an import > error exception will be thrown.
How to retrieve an output of a Python script using a Java program Question: I am having a problem with my code. I have a java class that calls a python script that get gps data. The problem is that I can call the script but I want to return the data to a string on the java side so I can use it in an array later. So basically all I want is to take the data from the python script and bring it to java as a string and place it in to an array. **python code** #! /usr/bin/python import os from gps import * from time import * import time import threading gpsd = None #seting the global variable os.system('clear') #clear the terminal (optional) class GpsPoller(threading.Thread): def __init__(self): threading.Thread.__init__(self) global gpsd #bring it in scope gpsd = gps(mode=WATCH_ENABLE) #starting the stream of info self.current_value = None self.running = True #setting the thread running to true def run(self): global gpsd while gpsp.running: gpsd.next() #this will continue to loop and grab EACH set of gpsd info to clear the buffer if __name__ == '__main__': gpsp = GpsPoller() # create the thread try: gpsp.start() # start it up while True: #It may take a second or two to get good data #print gpsd.fix.latitude,', ',gpsd.fix.longitude,' Time: ',gpsd.utc os.system('clear') print print ' GPS reading' print '----------------------------------------' print 'latitude ' , gpsd.fix.latitude print 'longitude ' , gpsd.fix.longitude time.sleep(5) #set to whatever except (KeyboardInterrupt, SystemExit): #when you press ctrl+c print "\nKilling Thread..." gpsp.running = False gpsp.join() # wait for the thread to finish what it's doing print "Done.\nExiting." **java code** Process p4 = null; //String commands4="sudo python test1.py"; // provision gpio pin #01 as an output pin and turn on try { p4 = Runtime.getRuntime().exec("sudo python test1.py"); InputStream is = p4.getInputStream(); int i = 0; while( (i = is.read() ) != -1) { System.out.print((char)i); lat break; } Answer: You might want to check for the `p4.exitCode()` to see if the python script was successfully invoked, and then if it wasn't successful you may check for `p4.getErrorStream()` to see why. Either way, generally the code should handle different exit codes because you may never be 100% confident that the calling to python script will always be successful.
Convert tsv file so i can use it for nodes and edges in python Question: I have this tsv file i would like to read and somehow count the numbers of nodes in a path This is how the parts of tsv file looks like: 6a3701d319fc3754 1297740409 166 14th_century;15th_century;16th_century;Pacific_Ocean;Atlantic_Ocean;Accra;Africa;Atlantic_slave_trade;African_slave_trade NULL 3824310e536af032 1344753412 88 14th_century;Europe;Africa;Atlantic_slave_trade;African_slave_trade 3 the paths is only the ones looking like this : 14th_century;15th_century; seperated by ';' my code so fare : import networkx as nx fh = open("test.tsv", 'rb') G = nx.read_edgelist("test.tsv", create_using=nx.DiGraph()) print G.nodes() print G.edges() So my question is how do i count the numbers of nodes touched by a path? Answer: I'm using the pandas library here for speed, you can install using `pip install pandas` and also check here: <http://pandas.pydata.org/> Firstly construct our dataframe from your sample code: In [39]: temp = """6a3701d319fc3754 1297740409 166 14th_century;15th_century;16th_century;Pacific_Ocean;Atlantic_Ocean;Accra;Africa;Atlantic_slave_trade;African_slave_trade NULL 3824310e536af032 1344753412 88 14th_century;Europe;Africa;Atlantic_slave_trade;African_slave_trade 3""" # construct the dataframe # in your case replace io.String() with the path to your tsv file df = pd.read_csv(io.StringIO(temp), sep='\s+', header=None, names=['a','b','c','d','e']) df Out[39]: a b c \ 0 6a3701d319fc3754 1297740409 166 1 3824310e536af032 1344753412 88 d e 0 14th_century;15th_century;16th_century;Pacific... NaN 1 14th_century;Europe;Africa;Atlantic_slave_trad... 3 [2 rows x 5 columns] In [65]: # use itertools to flatten our list of lists import itertools def to_edge_list(x): # split on semi-colon split_list = x.split(';') #print(split_list) # get our main node primary_node = split_list[0] # construct our edge list edge_list=[] # create a list comprehension from the split list edge_list = [(primary_node, x) for x in split_list[1:] ] #print(edge_list) return edge_list # now use itertools to flatten the list of lists into a single list combined_edge_list = list(itertools.chain.from_iterable(df['d'].apply(to_edge_list))) print(combined_edge_list) [('14th_century', '15th_century'), ('14th_century', '16th_century'), ('14th_century', 'Pacific_Ocean'), ('14th_century', 'Atlantic_Ocean'), ('14th_century', 'Accra'), ('14th_century', 'Africa'), ('14th_century', 'Atlantic_slave_trade'), ('14th_century', 'African_slave_trade'), ('14th_century', 'Europe'), ('14th_century', 'Africa'), ('14th_century', 'Atlantic_slave_trade'), ('14th_century', 'African_slave_trade')] # Now construct our networkx graph from the edge list In [66]: import networkx as nx G = nx.MultiDiGraph() G.add_edges_from(combined_edge_list) G.edges() Out[66]: [('14th_century', '15th_century'), ('14th_century', 'Africa'), ('14th_century', 'Africa'), ('14th_century', 'Atlantic_slave_trade'), ('14th_century', 'Atlantic_slave_trade'), ('14th_century', 'African_slave_trade'), ('14th_century', 'African_slave_trade'), ('14th_century', '16th_century'), ('14th_century', 'Accra'), ('14th_century', 'Europe'), ('14th_century', 'Atlantic_Ocean'), ('14th_century', 'Pacific_Ocean')] draw the graph (doesn't look pretty but what the hell): ![enter image description here](http://i.stack.imgur.com/eQ2Dg.png)
Python clear the screen code? Question: I am still trying to make my quiz, but I want to enter a clear the screen code for my questions. So, after researching, I found a code that works, but it puts my questions way to the bottom of the screen. Here is a screenshot I took: ![The Image is below](http://i.stack.imgur.com/23cCu.png) here is a example of the clear the screen code I found: print "\n" * 40 So I tried changing the "40" To "20" but there was no effects. I am operating on Mac so the import os os.system('blahblah') does not work. Please help! Answer: As @pNre noted, [this question](http://stackoverflow.com/questions/2084508/clear-terminal-in-python) shows you how to do this with ASCI escape sequences. If you'd like to do this using the `os` module, then on Mac the command is `clear`. import os os.system('clear') Note: The fact that you are on a Mac does not mean `os.system('blahblah')` will not work. It is more likely the command you are passing to `os.system` was erroneous. See answer below for how to do this on Windows/Linux.
Random Gaussian issues Question: I'm trying to generate a random.gauss numbers but I have message error. Here is my code: import sys,os import numpy as np from random import gauss previous_value1=1018.163072765074389 previous_value2=0.004264112033664 alea_var_n=random.gauss(1,2) alea_var_tau=random.gauss(1,2) new_var_n= previous_value1*(1.0+alea_var_n) new_var_tau=previous_value2*(1.0+alea_var_tau) print 'new_var_n',new_var_n print 'new_var_tau',new_var_tau I got this error: Traceback (most recent call last): File "lolo.py", line 15, in <module> alea_var_n=random.gauss(1,2) AttributeError: 'builtin_function_or_method' object has no attribute 'gauss' Someone know what's wrong, I'm a newbye with python. Or is it a numpy version problem. Answer: For a faster option, see Benjamin Bannier's solution (which I gave a +1 to). Your present code that you posted will not work for the following reason: your import statement from random import gauss adds `gauss` to your namespace but not `random`. You need to do this instead: alea_var_n = gauss(1, 2) The error in your post, however, is not the error you should get when you run the code that you have posted above. Instead, you will get the following error: NameError: name 'random' is not defined Are you sure you have posted the code that generated that error? Or have you somehow included the wrong error in your post?
Can't pass a QAbstractListModel to QML Question: I'm following [this PySide tutorial](http://qt-project.org/wiki/Selectable- list-of-Python-objects-in-QML) as close as possible using PyQt5. When I run my code, I get this error: `ReferenceError: pythonListModel is not defined`, and the list shows up black with no items. This is my code def main(): platform = Platform("Windows") platform_wrp = qml_platforms.PlatformsWrapper(platform) platform_model = qml_platforms.PlatformsListModel([platform_wrp]) app = QGuiApplication(sys.argv) engine = QQmlApplicationEngine(QUrl("main.qml")) context = engine.rootContext() context.setContextProperty('pythonListModel', platform_model) window = engine.rootObjects()[0] window.show() sys.exit(app.exec_()) if __name__ == '__main__': main() my model and wrapper class PlatformsWrapper(QObject): def __init__(self, platform): QObject.__init__(self) self.platform = platform def full_name(self): return str(self.platform.full_name) changed = pyqtSignal() full_name = pyqtProperty("QString", _full_name, notify=changed) class PlatformsListModel(QAbstractListModel): def __init__(self, platforms): QAbstractListModel.__init__(self) self.platforms = platforms def rowCount(self, parent=QModelIndex()): return len(self.platforms) def data(self, index): if index.isValid(): return self.platforms[index.row()] return None and my QML import QtQuick 2.1 import QtQuick.Controls 1.1 ApplicationWindow{ ListView { id: pythonList width: 400 height: 200 model: pythonListModel delegate: Component { Rectangle { width: pythonList.width height: 40 color: ((index % 2 == 0)?"#222":"#111") Text { id: title elide: Text.ElideRight text: model.platform.full_name color: "white" font.bold: true anchors.leftMargin: 10 anchors.fill: parent verticalAlignment: Text.AlignVCenter } MouseArea { anchors.fill: parent } } } } } Why can't Qt find my contextProperty? Answer: The problem is that "main.qml" is loaded before you set context property. Try load file after you setup your context: def main(): platform = Platform("Windows") platform_wrp = qml_platforms.PlatformsWrapper(platform) platform_model = qml_platforms.PlatformsListModel([platform_wrp]) app = QGuiApplication(sys.argv) engine = QQmlApplicationEngine() context = engine.rootContext() context.setContextProperty('pythonListModel', platform_model) engine.load( QUrl("main.qml") ) #load after context setup window = engine.rootObjects()[0] window.show() sys.exit(app.exec_())
Formatting a string by word at a specific character length Question: I don't see this question anywhere in the database - if it's a duplicate, please let me know! I'm trying to format a string to a certain length by word; I have a string of arbitrary length and I would simply like to add newlines in every **n** characters, separated by word so that the string is not split in the middle of a word. str = "This is a string with length of some arbitrary number greater than 20" count=0 tmp="" for word in str.split(): tmp += word + " " count += len(word + " ") if count > 20: tmp += "\n" count = 0 str = tmp print str I'm certain that there is an embarrassingly simple Pythonic way to do this, but I don't know what it is. Suggestions? Answer: Use the [textwrap](http://docs.python.org/library/textwrap.html) module. For your case [textwrap.fill](https://docs.python.org/2/library/textwrap.html#textwrap.fill) should have it: >>> import textwrap >>> s = "This is a string with length of some arbitrary number greater than 20" >>> print textwrap.fill(s, 20) This is a string with length of some arbitrary number greater than 20
How to output integer arrays to file in python? Question: I have 3000000 ints' long array which I want to output to a file. How can I do that? Also, is this for i in range(1000): for k in range(1000): (r, g, b) = rgb_im.getpixel((i, k)) rr.append(r) gg.append(g) bb.append(b) d.extend(rr) d.extend(gg) d.extend(bb) a good practice to join array together? All of the arrays are declared like this `d = array('B')` EDIT: Managed to output all int`s delimited by ' ' with this from PIL import Image import array side = 500 for j in range(1000): im = Image.open(r'C:\Users\Ivars\Desktop\RS\Shape\%02d.jpg' % (j)) rgb_im = im.convert('RGB') d = array.array('B') rr = array.array('B') gg = array.array('B') bb = array.array('B') f = open(r'C:\Users\Ivars\Desktop\RS\ShapeData\%02d.txt' % (j), 'w') for i in range(side): for k in range(side): (r, g, b) = rgb_im.getpixel((i, k)) rr.append(r) gg.append(g) bb.append(b) d.extend(rr) d.extend(gg) d.extend(bb) o = ' '.join(str(t) for t in d) print('#', j, ' - ', len(o)) f.write(o) f.close() Answer: if you're using python >= 2.6 then you can use print functions from the _future_! from __future__ import print_function #your code # This will print out a string representation of list to the file. # If you need it formatted differently, then you'll have to construct the string yourself print(d, file=open('/path/to/file.txt','w') #you can join the list items with an empty string to get only the numbers print("".join(d),file=('/path/to/file.txt','w')) This has the side effect of turning print from a statement into a function, so you'll have to wrap whatever you want printed in ()
How to pass a dict to a python thread that can be changed from outside of thread without using queue Question: I would like to have a shared dict between my threads without using Queue. I did it before by making thread with an object in python but now I want to make thread with just one function of object not all of it. my simplified code is as follow: #!/usr/bin/python import threading import time class WebSocket(threading.Thread): def __init__(self, server=1, sock=1, address=1): self.s1=server self.s2=sock self.s3=address print "salam" def CheckThread(self): self.a={'1':1, '2':2} s=threading.Thread(target=self.SockFun, kwargs=self.a) s.deamon=True s.start() while(1): self.a['1']=self.a['1']+1 time.sleep(1) def SockFun(self,**kwargs): pass class SimpleEcho(WebSocket): def SockFun(self,**kwargs): while(1): print kwargs time.sleep(1) def handleMessage(self): self.CheckThread() s=SimpleEcho() s.handleMessage() my printed dict element '1' of kwargs does not increase as expected inside thread: Answer: Using the `kwargs` mechanism causes the dict elements to be copied into `SimpleEcho`. After they are there, changing the original doesn't make a difference to what is printed. A quick way to see this is to change `print kwargs` to `print self.a`. Alternatively you can change `kwargs=self.a` to `kwargs={"argh":self.a}`. This way, `kwargs` will still be copied, but that copy will contain a reference to the original `self.a`. And shouldn't you be using some kind of locking?
Python: Send IGMP packets with Scapy Question: I would like to send IGMP packets using scapy, specifically IGMP Leave, IGMP Membership report. Is it possible to do so? **UPDATE:** I was able to eventually generate them. Had to do the following: 1) Install scapy v.2.2.0 as it's described here (including minor alteration in setup.py): [scapy's contrib is missing after installing scapy on both windows and fedora](http://stackoverflow.com/questions/17412909/scapys-contrib-is- missing-after-installing-scapy-on-both-windows-and-fedora) 2) You need to use file from contribution package (features not added to the core of scapy): import scapy.contrib.igmp igmpPacket = scapy.contrib.igmp.IGMP() Answer: Yes, it is possible to send IGMP packets. After googling a bit, I came up with some useful links that can help you in some direction. On github there exists a [IGMP](https://github.com/d1b/scapy/blob/master/scapy/contrib/igmp.py) and [IGMPv3](http://bb.secdev.org/scapy/src/0d201eca59df/scapy/contrib/igmpv3.py) implementation in scapy. Here is an interesting [mailing list](http://search.gmane.org/?query=igmp&group=gmane.comp.security.scapy.general) too. Also, this [post](http://blog.mmmonk.net/2012/01/quick-scapy-example-for- linux-kernel.html) has an other interesting stuff related to IGMP.
In Ipython, does return statement works as Print? Question: I have a Python code as follows, I wrote a function as the same name as the Program name and gave an entry point for the function as follows: import math def Problem1(): total=0 for i in range(1000): if i%3 == 0 or i%5==0 or i%6==0 or i%9==0: total=total+i return total Now I went to terminal ran IPython, and then executed the following statements: import Problem1 Problem1.Problem1() It printed the output, even though I dont have a print statement, I have given a return statement, so what is happening here? Another question : How do I run this directly from the command line, ie how to give something equivalent to void main() of C in Python? Answer: What IPython does is it prints the output if you simply call a function or a variable so if you just enter a variable name and hit enter it will print it. the same thing is happening for a function output. This is standard behavior in an interactive shell. The idea behind this is that if you do interactive work you usually want to see your output directly. To run this you would put your code in a *.py file where you actually call the function at the bottom of your file. so you don't need to do void main(). You then execute the code with the Interperter, i.e. python yourfile.py however there is a remotely [similar pattern](http://stackoverflow.com/questions/419163/what-does-if-name-main-do) to the void main() thingy Note that because Python is an interpreted language, you can simply put print "hello world" in a *.py file call it with the python executable and it right away works. There is no "main()" function that you need to define
Not able to access twitter after a lot of try Question: I work on windows 7 and i am trying to access twitter using tweepy and even twitter1.14.2-python.But i am not able crack it. Help needed. _**TWEEPY_** import tweepy OAUTH_TOKEN = "defined here" OAUTH_SECRET = "defined here" CONSUMER_KEY = "defined here" CONSUMER_SECRET = "defined here" auth = tweepy.OAuthHandler(CONSUMER_KEY, CONSUMER_SECRET) auth.set_access_token(OAUTH_TOKEN, OAUTH_SECRET) api = API.GetUserTimeline(screen_name="yyy") Error : name 'API' is not defined _**TWITTER 1.14.2_** import twitter from twitter import * tw = Twitter(auth=OAuth(OAUTH_TOKEN, OAUTH_SECRET,CONSUMER_KEY, CONSUMER_SECRET)) tw.statuses.home_timeline() tw.statuses.user_timeline(screen_name="yyy") Error : No module named OAuth _Where i am going wrong ?_ Answer: As there is no `GetUserTimeline` defined/declared in [tweepy.API](http://pythonhosted.org/tweepy/html/api.html#tweepy-api-twitter- api-wrapper) class, so am asuming that you intend to try the `GetUserTimeline` method of [twitter.Api](http://inventwithpython.com/twitter.html#Api- GetUserTimeline) class. The `API` is exposed via the `twitter.Api` class. To create an instance of the `twitter.Api` class: >>> import twitter >>> api = twitter.Api() To create an instance of the `twitter.Api` with login credentials. >>> api = twitter.Api(consumer_key='consumer_key', consumer_secret='consumer_secret', access_token_key='access_token', access_token_secret='access_token_secret') To fetch a single user's public status messages, where `user` is either a `Twitter "short name" or their user id` >>> statuses = api.GetUserTimeline(user) >>> print [s.text for s in statuses]
Gunicorn is unable to find my wsgi file, not able to load python? Question: So I am trying to run a gunicorn script, following a tutorial I found in the Internet. Here is my folder structure: (today_project)[littlem@server1 today_project]$ tree . -L 2 . ├── bin │   ├── activate │   ├── activate.csh │   ├── activate.fish │   ├── activate_this.py │   ├── django-admin.py │   ├── django-admin.pyc │   ├── easy_install │   ├── easy_install-2.7 │   ├── gunicorn │   ├── gunicorn_django │   ├── gunicorn_paster │   ├── gunicorn_start │   ├── pip │   ├── pip2 │   ├── pip2.7 │   ├── python -> python2.7 │   ├── python2 -> python2.7 │   └── python2.7 ├── include │   ├── python2.6 -> /usr/include/python2.6 │   └── python2.7 -> /usr/local/include/python2.7 ├── lib │   ├── python2.6 │   └── python2.7 ├── manage.py ├── run │   └── gunicorn.sock ├── today │   ├── #app files ├── today_project │   ├── __init__.py │   ├── __init__.pyc │   ├── __pycache__ │   ├── settings.py │   ├── settings.pyc │   ├── urls.py │   ├── urls.pyc │   ├── wsgi.py │   └── wsgi.pyc └── TODO.md When I run gunicorn today_project.wsgi:application from my virtualenv, it works fine. But when I run this script (I pretty much copied it from somewhere): #!/bin/bash NAME="today" # Name of the application DJANGODIR=~/today_project/today_project # Django project directory SOCKFILE=~/today_project/run/gunicorn.sock # we will communicte using this unix socket USER=ferski # the user to run as GROUP=ferski # the group to run as NUM_WORKERS=3 # how many worker processes should Gunicorn spawn DJANGO_SETTINGS_MODULE=today.settings # which settings file should Django use DJANGO_WSGI_MODULE=today.wsgi # WSGI module name echo "Starting $NAME as `whoami`" # Activate the virtual environment cd $DJANGODIR source ../bin/activate export DJANGO_SETTINGS_MODULE=$DJANGO_SETTINGS_MODULE export PYTHONPATH=$DJANGODIR:$PYTHONPATH # Create the run directory if it doesn't exist RUNDIR=$(dirname $SOCKFILE) test -d $RUNDIR || mkdir -p $RUNDIR # Start your Django Unicorn # Programs meant to be run under supervisor should not daemonize themselves (do not use --daemon) exec ../bin/gunicorn ${DJANGO_WSGI_MODULE}:application \ --name $NAME \ --workers $NUM_WORKERS \ --user=$USER --group=$GROUP \ --log-level=debug \ --bind=unix:$SOCKFILE I have the following error Traceback (most recent call last): File "/home/ferski/today_project/lib/python2.7/site-packages/gunicorn/arbiter.py", line 495, in spawn_worker worker.init_process() File "/home/ferski/today_project/lib/python2.7/site-packages/gunicorn/workers/base.py", line 106, in init_process self.wsgi = self.app.wsgi() File "/home/ferski/today_project/lib/python2.7/site-packages/gunicorn/app/base.py", line 114, in wsgi self.callable = self.load() File "/home/ferski/today_project/lib/python2.7/site-packages/gunicorn/app/wsgiapp.py", line 62, in load return self.load_wsgiapp() File "/home/ferski/today_project/lib/python2.7/site-packages/gunicorn/app/wsgiapp.py", line 49, in load_wsgiapp return util.import_app(self.app_uri) File "/home/ferski/today_project/lib/python2.7/site-packages/gunicorn/util.py", line 354, in import_app __import__(module) ImportError: No module named today_project.wsgi 2014-04-06 16:09:28 [19420] [INFO] Worker exiting (pid: 19420) 2014-04-06 16:09:28 [19407] [INFO] Shutting down: Master 2014-04-06 16:09:28 [19407] [INFO] Reason: Worker failed to boot. So I guess its the problem with python version? I dont know what I am doing to be honest when I do `export PYTHONPATH=$DJANGODIR:$PYTHONPATH` but I guess this is where the problem lies Answer: I think your DJANGODIR should just be `~/today_project/`. It's the root of the tree, not the inner directory. There are a few other things wrong, too: in particular, since you're running in a virtualenv, you shouldn't need to change the PYTHONPATH at all.
How to import correctly my function from parent folder Question: I have the following layout: /project /thomas /users /src code_alpha.py /tests code_beta.py I tried: /project /thomas /users __init__.py /src code_alpha.py /tests code_beta.py with `from users.src import code_alpha` also tried: /project /thomas /users __init__.py /src code_alpha.py __init__.py /tests code_beta.py with `from users.src import code_alpha` I tried to solve the problem with this [guide](https://docs.python.org/2/tutorial/modules.html) and some similiar topics here, but could not figure out. Adding the directory to my path did not solve the problem. edit: updated layout. Answer: Try adding `__init__.py` to `somefolder_3`. Then in `code_beta.py` you will be able to write `from somefolder_3.somefolder_4 import code_alpha`
ImportError: matplotlib requires dateutil; import matplotlib.pyplot as plt Question: Am new to progamming and Python, i keep getting the error below when i run my program. Someone advised i should use pip to solve it. But cant pip get installed using the cmd. Though i suceeded using Powershell but still cant make it work. How do i solve this, any tips will go along way. Thanks Traceback (most recent call last): File "<pyshell#0>", line 1, in <module> from satmc import satmc File "C:\Python27\starb_models_grid1\satmc.py", line 3, in <module> import matplotlib.pyplot as plt File "C:\Python27\lib\site-packages\matplotlib\__init__.py", line 110, in <module> raise ImportError("matplotlib requires dateutil") ImportError: matplotlib requires dateutil Am using version 2.7.3 Answer: You need to install various packages to get `numpy` working correctly. 1. libsvm-3.17.win32-py2.7 2. pyparsing-2.0.1.win32-py2.7 3. python-dateutil-2.2.win32-py2.7 4. pytz-2013.9.win32-py2.7 5. six-1.5.2.win32-py2.7 6. scipy-0.13.3.win32-py2.7 7. numpy-MKL-1.8.0.win32-py2.7 8. Matplotlib Download all the binaries from this [link](http://www.lfd.uci.edu/~gohlke/pythonlibs/) and install and then you will have a working numpy installation.
Trouble Installing Pillow: Why Am I Receiving Errors? Question: I'm attempting to install pillow via pip (i.e. `sudo pip install pillow`) but without much success. Can anyone tell me what the problem is? Here are the errors I receive: clang: error: unknown argument: '-mno-fused-madd' [-Wunused-command-line-argument-hard-error-in-future] clang: note: this will be a hard error (cannot be downgraded to a warning) in the future error: command 'clang' failed with exit status 1 ---------------------------------------- Cleaning up... Command /usr/bin/python -c "import setuptools, tokenize;__file__='/private/tmp/pip_build_root/pillow/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-l7hSHg-record/install-record.txt --single-version-externally-managed --compile failed with error code 1 in /private/tmp/pip_build_root/pillow Answer: try with sudo ARCHFLAGS=-Wno-error=unused-command-line-argument-hard-error-in-future pip install pillow you will see a lot of warnings but it worked for me. the unused arguments was preventing further install of pillow. the above tells it to not treat the unused argument as an error. Source: [a/22774631/1142814](http://stackoverflow.com/a/22774631/1142814) EDIT: I link here the official issue you linked in your comment, maybe it can be helpful for someone else: <https://github.com/python- imaging/Pillow/issues/527>
Convert black and white array into an image in python? Question: I have an array of 50x50 elements of which each is either True or False - this represents a 50x50 black and white image. I can't convert this into image? I've tried countless different functions and none of them work. import numpy as np from PIL import Image my_array = np.array([[True,False,False,False THE DATA IS IN THIS ARRAY OF 2500 elements]]) im = Image.fromarray(my_array) im.save("results.jpg") ^ This one gives me: "Cannot handle this data type". I've seen that PIL has some functions but they only convert a list of RGB pixels and I have a simple black and white array without the other channels. Answer: First you should make your array 50x50 instead of a 1d array: my_array = my_array.reshape((50, 50)) Then, to get a standard 8bit image, you should use an unsigned 8-bit integer dtype: my_array = my_array.reshape((50, 50)).astype('uint8') But you don't want the `True`s to be `1`, you want them to be `255`: my_array = my_array.reshape((50, 50)).astype('uint8')*255 Finally, you can convert to a PIL image: im = Image.fromarray(my_array) I'd do it all at once like this: im = Image.fromarray(my_array.reshape((50,50)).astype('uint8')*255)
Determining a functions output as print or write Question: I need to determine the output of a function if whether the function is printing a statement, or writing it out on a .txt file. Is there a way to do this in Python? I thought perhaps the hasattr('myfunction', '**str** ') might work, but it did not. Examples of functions: def x(): print('dog') def y(): open("file.txt", "w").write("dog") Answer: The print function can take more arguments than just whats going to be written: print(*objects, sep=' ', end='\n', file=sys.stdout) So you could write a wrapper function for print that also appends a boolean to a list that is true if the file was sys.stdout and false otherwise. import sys write_history = [] def write(*objects, sep=' ', end='\n', file=sys.stdout): print(*objects, sep=sep, end=end, file=file) write_history.append(file==sys.stdout) Then just always use the write function, and when you want to test the output of a function, simply clear the write_history and call that function.
How can I make itemgetter to take input from list variable? Question: How can I use itemgetter with list variable instead of integers? For example: from operator import itemgetter z = ['foo', 'bar','qux','zoo'] id = [1,3] I have no problem doing this: In [5]: itemgetter(1,3)(z) Out[5]: ('bar', 'zoo') But it gave error when I do this: In [7]: itemgetter(id)(z) --------------------------------------------------------------------------- TypeError Traceback (most recent call last) <ipython-input-7-7ba47b19f282> in <module>() ----> 1 itemgetter(id)(z) TypeError: list indices must be integers, not list How can I make itemgetter to take input from list variable correctly, i.e. using `id`? Answer: When you do: print itemgetter(id)(z) you are passing a `list` to `itemgetter`, while it expects indices (integers). **What can you do?** You can unpack the `list` using `*`: print itemgetter(*id)(z) to visualize this better, both following calls are equivalent: print itemgetter(1, 2, 3)(z) print itemgetter(*[1, 2, 3])(z)
Get value from detect colour python opencv Question: For my project, I want to control an RC car to avoid red obstacles using a webcam camera running `Raspberry Pi`. I can control my RC car, but I don't know much about `openCV`. I can also detect selected colours using the webcam, but I do not know how to get the colour value from the image to my RC car. The issue that I am having is that my car does not know that a blue object is in front of the camera. Here is my code: import cv2 import numpy as np cap = cv2.videoCapture(0) while(1): # take each frame _,frame=cap.read() #convert BGR to HSV hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV) #define range of blue color in HSV lower_blue = np.array([160,50,50],dtype=np.uint8) uper_blue np.array([179,255,255],dtype=np.uint8) #Threshold the HSV image to get only blue colors mask = cv2.inRange(hsv,lower_blue,upper_blue) cv2.imshow('mask',mask) k=cv2.waitKey(5) &0xFF if k == 27 : break cv2.destroyAllwindows() Answer: You can get the color values using: values = img[100,100] You have to Check if Mask is 255 (Pixel in Range) and get the color from your image (hsv). To iterate over the image you can use: img.shape which returns rows, columns, and channels. In total you get something like: row, col, chan = img.shape for r in row: for c in col: if mask[r,c] == 255: print img[r,c] You can find more information in the [OpenCV Python Tutorial](http://docs.opencv.org/trunk/doc/py_tutorials/py_core/py_basic_ops/py_basic_ops.html).
Why is module math called "built-in"? Question: AFAIK, Python `builtins` refers to those exceptions and functions contained in `__builtins__`: >>> import builtins # import __builtin__ in Python 2 >>> dir(builtins) # dir(__builtin__) for Python 2 ['ArithmeticError', 'AssertionError', 'AttributeError', 'BaseException', 'BlockingIOError', 'BrokenPipeError', 'BufferError', 'BytesWarning', ...many more... 'ord', 'pow', 'print', 'property', 'quit', 'range', 'repr', 'reversed', 'round', 'set', 'setattr', 'slice', 'sorted', 'staticmethod', 'str', 'sum', 'super', 'tuple', 'type', 'vars', 'zip'] But look at the code below (both Python2 and 3 gave the same results): >>> globals() {'__name__': '__main__', '__builtins__': <module 'builtins' (built-in)>, '__loader__': <class '_frozen_importlib.BuiltinImporter'>, '__doc__': None, '__package__': None} >>> import threading >>> import math >>> globals() {'__name__': '__main__', '__builtins__': <module 'builtins' (built-in)>, '__loader__': <class '_frozen_importlib.BuiltinImporter'>, '__doc__': None, '__package__': None, 'threading': <module 'threading' from C:\\ProgramFiles\\Python3.3\\lib\\threading.py'>, 'math': <module 'math' (built-in)>} On the last line, module `math` is called `built-in`. Why? What's the difference between module `math` and other modules like `threading`? Answer: In your case the `math` module was included into the main Python library itself (`libpython2.7.{so,dll,dylib}`) when the library was built. This is possible since the module is written in C rather than pure Python. Other modules that are like this include `sys` and `posix`.
how to take variable from different `def()` function to another - python Question: I have two different functions like : def messageWindow(): # all the necessary operations feature_matrix_db = zip( B_mean , G_mean , R_mean, cont_list , ene_list , homo_list , cor_list, dis_list) return feature_matrix_db def open(): #all the necessary operations feature_matrix_ip = zip( B_mean1 , G_mean1 , R_mean1, cont_list1 , ene_list1 , homo_list1 , cor_list1 , dis_list1) return feature_matrix_ip def result(): COLUMNS = 12 image_count = 0 resultlist_key = [] result_list = list() i = 0 a_list = list() b_list = list() a_list.append(feature_matrix_ip) while i < 70: b_list.append(feature_matrix_db[i]) dist = distance.euclidean(a_list,b_list[i]) result_list.append(dist) resultlist_key = OrderedDict(sorted(enumerate(result_list),key=lambda x:x[0])).keys() i = i + 1 res_lst_srt = {'values': result_list,'keys':resultlist_key} res_lst_srt['values'], res_lst_srt['keys'] = zip(*sorted(zip(res_lst_srt['values'], res_lst_srt['keys']))) key = res_lst_srt['keys'] for i1,val in enumerate(key): if i1 < 4: image_count += 1 r, c = divmod(image_count, COLUMNS) im = Image.open(resizelist[val]) tkimage = ImageTk.PhotoImage(resized) myvar = Label(win, image=tkimage) myvar.image = tkimage myvar.grid(row=r, column=c) First two `def()` function will return `feature_matrix_db` and `feature_matrix_ip`, and I want these results to be imported into the next `def()` function **result**. And it is giving an error like : im = Image.open(resizelist[val]) File "E:\Canopy\System\lib\site-packages\PIL\Image.py", line 1956, in open prefix = fp.read(16) AttributeError: 'numpy.ndarray' object has no attribute 'read' Any suggestions are welcome. Thanks in advance! Answer: You probably want to read up about namespacing and scoping in python. There's some info here: <https://docs.python.org/2/tutorial/classes.html> For example your `messageWindow()` function: def messageWindow(): # all the necessary operations feature_matrix_db = zip( B_mean , G_mean , R_mean, cont_list , ene_list , homo_list , cor_list, dis_list) return feature_matrix_db But where are `B_mean`, `G_mean`, `R_mean`, `cont_list`, `ene_list`, `homo_list`, `cor_list` and `dis_list` defined? You can pass them to `messageWindow()` as arguments: def messageWindow(B_mean , G_mean , R_mean, cont_list , ene_list , homo_list , cor_list, dis_list): # all the necessary operations feature_matrix_db = zip( B_mean , G_mean , R_mean, cont_list , ene_list , homo_list , cor_list, dis_list) return feature_matrix_db or assign some value to them within the function, or assign some value to them outside of the function using the `global` keyword. But you can't just call them without having ever said what values they take. Let's look at the first few lines of `result()`: def result(): COLUMNS = 12 image_count = 0 resultlist_key = [] result_list = list() i = 0 a_list = list() b_list = list() a_list.append(feature_matrix_ip) Again, where is `feature_matrix_ip` defined? What you could do instead is this: feature_matrix_ip = open() #super bad idea to call your function open() a_list.append(feature_matrix_ip)
TemplateDoesNotExist at / Question: Hej! Many threads here had the same caption, but none of them solved my problem. I have a Django site an can access /admin (but it looks ugly). But on / there appears the following error page (`DEBUG = True` in `settings.py`): TemplateDoesNotExist at / index.html Request Method: GET Request URL: http://iecl.uni-potsdam.de/ Django Version: 1.4.5 Exception Type: TemplateDoesNotExist Exception Value: index.html Exception Location: /usr/lib/python2.7/dist-packages/django/template/loader.py in find_template, line 138 Python Executable: /usr/bin/python Python Version: 2.7.3 Python Path: ['/home/python/iecl/lib/python2.7/site-packages/distribute-0.6.28-py2.7.egg', '/home/python/iecl/lib/python2.7/site-packages/pip-1.2.1-py2.7.egg', '/usr/lib/python2.7', '/usr/lib/python2.7/plat-linux2', '/usr/lib/python2.7/lib-tk', '/usr/lib/python2.7/lib-old', '/usr/lib/python2.7/lib-dynload', '/usr/local/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages', '/usr/lib/pymodules/python2.7', '/home/python/iecl/lib/python2.7/site-packages', '/home/django/django'] Server time: Mon, 7 Apr 2014 11:28:46 +0200 Template-loader postmortem Django tried loading these templates, in this order: Using loader django.template.loaders.filesystem.Loader: /home/django/django/templates/iecl_dev/index.html (File does not exist) Using loader django.template.loaders.app_directories.Loader: /usr/lib/python2.7/dist-packages/django/contrib/auth/templates/index.html (File does not exist) /usr/lib/python2.7/dist-packages/django/contrib/admin/templates/index.html (File does not exist) In fact, the file /home/django/django/templates/iecl_dev/index.html does exist and I also tried `chmod o+r index.html` without success. The output of `python iecl_dev/manage.py runserver 0.0.0.0:0` is Validating models... 0 errors found Django version 1.4.5, using settings 'iecl_dev.settings' Development server is running at http://0.0.0.0:0/ Quit the server with CONTROL-C. so everything seems fine here. What perplexes me: The *.pyc files are created automatically when *.py files are run, right? After `python iecl_dev/manage.py runserver 0.0.0.0:0` there is a file `/home/django/django/iecl_dev/settings.pyc` created. But it is not created, when I load the page in my web browser. Does that mean, the settings.py is never loaded? And how can Django say, a file, which exists, would not exist? Edit¹: My settings.py looks as follows: import django.conf.global_settings as DEFAULT_SETTINGS import os DEBUG = True TEMPLATE_DEBUG = DEBUG ADMINS = ( ) SETTINGS_PATH = os.path.realpath(os.path.dirname(__file__)) MANAGERS = ADMINS DATABASES = { $ 'default': { $ 'ENGINE': 'django.db.backends.mysql', # Add 'postgresql_psycopg2', 'postgresql', 'mysql', 'sqlite3' or 'oracle'. 'NAME': 'iecl', # Or path to database file if using sqlite3. 'USER': 'iecl', # Not used with sqlite3. 'PASSWORD': '<xxx>', # Not used with sqlite3. 'HOST': '', # Set to empty string for localhost. Not used with sqlite3. $ 'PORT': '', # Set to empty string for default. Not used with sqlite3. } } TIME_ZONE = 'Europe/Berlin' LANGUAGE_CODE = 'en-us' SITE_ID = 1 USE_I18N = True MEDIA_ROOT = '/var/www/django_media/iecl_dev/media/' MEDIA_URL = '' ADMIN_MEDIA_PREFIX = '/media/admin_media/' SECRET_KEY = '<xxx>' TEMPLATE_LOADERS = ( 'django.template.loaders.filesystem.Loader', 'django.template.loaders.app_directories.Loader', ) MIDDLEWARE_CLASSES = ( 'django.middleware.csrf.CsrfViewMiddleware', 'django.middleware.common.CommonMiddleware', 'django.contrib.sessions.middleware.SessionMiddleware', 'django.contrib.auth.middleware.AuthenticationMiddleware', 'django.contrib.messages.middleware.MessageMiddleware', ) ROOT_URLCONF = 'iecl_dev.urls' TEMPLATE_DIRS = ( os.path.join(SETTINGS_PATH, 'templates'), ) INSTALLED_APPS = ( 'django.contrib.auth', 'django.contrib.contenttypes', 'django.contrib.sessions', 'django.contrib.sites', 'iecl_dev.showStudents', 'django.contrib.admin', ) TEMPLATE_CONTEXT_PROCESSORS = DEFAULT_SETTINGS.TEMPLATE_CONTEXT_PROCESSORS + ( ) Edit²: The contents of `/home/django/django/` are as follows: /home/django/django/: iecl2 iecl_dev templates /home/django/django/iecl2: __init__.py __init__.pyc manage.py settings.py settings.pyc showStudents urls.py urls.pyc /home/django/django/iecl2/showStudents: __init__.py __init__.pyc admin.py context_processors.py models.py models.pyc views.py views.pyc /home/django/django/iecl_dev: __init__.py __init__.pyc manage.py piwik settings.py settings.pyc showStudents urls.py urls.pyc /home/django/django/iecl_dev/piwik: __init__.py app_settings.py context_processors.py models.py tests.py urls.py views.py /home/django/django/iecl_dev/showStudents: __init__.py __init__.pyc admin.py context_processors.py models.py models.pyc views.py /home/django/django/templates: iecl iecl_dev /home/django/django/templates/iecl: 500.html admin changePW.html editStudent.html feedback.html feedback_thanks.html index.html location.html login.html page.html password_changed.html showStudent.html studentsOverview.html /home/django/django/templates/iecl/admin: 404.html 500.html actions.html app_index.html auth base.html base_site.html change_form.html change_list.html change_list_results.html date_hierarchy.html delete_confirmation.html delete_selected_confirmation.html edit_inline filter.html includes index.html invalid_setup.html login.html object_history.html pagination.html prepopulated_fields_js.html search_form.html showStudents submit_line.html /home/django/django/templates/iecl/admin/auth: user /home/django/django/templates/iecl/admin/auth/user: add_form.html change_password.html /home/django/django/templates/iecl/admin/edit_inline: stacked.html tabular.html /home/django/django/templates/iecl/admin/includes: fieldset.html /home/django/django/templates/iecl/admin/showStudents: pagecontent userpagecontent /home/django/django/templates/iecl/admin/showStudents/pagecontent: change_form.html /home/django/django/templates/iecl/admin/showStudents/userpagecontent: change_form.html /home/django/django/templates/iecl_dev: 500.html __init__.py admin changePW.html editStudent.html feedback.html feedback_thanks.html index.html location.html login.html page.html password_changed.html piwik showStudent.html studentsOverview.html /home/django/django/templates/iecl_dev/admin: 404.html 500.html actions.html app_index.html auth base.html base_site.html change_form.html change_list.html change_list_results.html date_hierarchy.html delete_confirmation.html delete_selected_confirmation.html edit_inline filter.html includes index.html invalid_setup.html login.html object_history.html pagination.html prepopulated_fields_js.html search_form.html showStudents submit_line.html /home/django/django/templates/iecl_dev/admin/auth: user /home/django/django/templates/iecl_dev/admin/auth/user: add_form.html change_password.html /home/django/django/templates/iecl_dev/admin/edit_inline: stacked.html tabular.html /home/django/django/templates/iecl_dev/admin/includes: fieldset.html /home/django/django/templates/iecl_dev/admin/showStudents: pagecontent userpagecontent /home/django/django/templates/iecl_dev/admin/showStudents/pagecontent: change_form.html /home/django/django/templates/iecl_dev/admin/showStudents/userpagecontent: change_form.html /home/django/django/templates/iecl_dev/piwik: tracking.html Edit³: Ok. This is solved for me now. The solution was a conglomerate of different things. One of the problems was the missing rights. The user that executes Django, could not list the contents of the templates/ directory. `chmod o+x templates/` did the job. Then there were some settings in the settings.py, that changed the place to look for the templates from templates/iecl_dev/ to iecl_dev/templates/. I saw this wrong path in the error message in my web browser. But simply reverting the settings.py to the old version, was not enough. Some service(s) needed to be restarted. I simply rebooted the machine and everything was fine. Miraculously, the /admin/ page now looks nice as well. Many thanks for all your tips. Answer: From what you've shown, I think you may have a problem with your project layout. Usually, it is set as follows : ├── manage.py ├── yourproject │   ├── __init__.py │   ├── settings.py │   ├── templates │   ├── urls.py │   ├── wsgi.py │   └── wsgi.pyc ├── yourfirstapp │   ├── __init__.py │   ├── admin.py │   ├── models.py │   ├── templates │   ├── tests.py │   ├── urls.py │   └── views.py ├── yoursecondapp ├── __init__.py ├── admin.py ├── models.py ├── templates ├── tests.py ├── urls.py └── views.py As you can see, each app inside your project can have it's own `templates` directory.`yourproject` is a bit particuliar, because it also stores unique files, such as `settings.py`and `wsgi.py`. However, you can consider and use it as an app. Now, if you want to use a template stored in `yourproject/templates`, you'll have to add `yourproject` to your `INSTALLED_APPS` settings. Does it helps ? If not, can you edit your original post with your project layout ?
How to fit parser in my python script Question: Normally, if I have to perform an overlap between multiple files, I just execute: python -c 'import sys;print "".join(sorted(set.intersection(*[set(open(a).readlines()) for a in sys.argv[1:]])))' File1 File2 File3 File4 .... But if I have to get this through a parser, how can I do it? A short example will be enough around this script, and after that I can play around. Actually I want the user to give two input: Files on which ioperation is to be performed and the the operation here it is intersection. Kindly help, instead of voting the post to close. I think I have to show what I am doing, and here is an example of that: usage = "Usage: %prog -i <file1>[,<file2>,...] -o <out> -ops " version = "%prog " + str(VERSION) parser = OptionParser(version=version, usage=usage) group1 = OptionGroup(parser, 'Optional') parser.add_option("-i", dest="featurefile", help="Gene list", metavar="FILE") parser.add_option("-o", dest="outfile", help="output file (type determined by extension)", metavar="FILE") # Optional arguments group1.add_option("--op", dest="operation", help="Intersection, Union & Uniques (default Intersection)", default=None, type="string") parser.add_option_group(group1) (options, args) = parser.parse_args() Now this set is parser thing (done), now the second step is to get the operation (intersection) and the files and perform them. At this step I am lost. Thank you Answer: Since you are using Python 2.7, use the [argparse](https://docs.python.org/2.7/library/argparse.html) module instead of the older `optparse`: import argparse import itertools as IT VERSION = 0.1 version = "%(prog)s " + str(VERSION) operation = { 'intersection': set.intersection, 'union': set.union, 'uniques': set.difference} parser = argparse.ArgumentParser() parser.add_argument('--version', action='version', version=version) parser.add_argument('-i', '--featurefiles', nargs='+', help='Gene list', metavar='FILE') parser.add_argument('-o', '--outfile', help="output file (type determined by extension)", metavar='FILE') parser.add_argument('--op', dest="operation", help="Intersection, Union & Uniques (default Intersection)", default='intersection', # can't use type=operation.get. See http://bugs.python.org/issue16516 type=lambda x: operation[x]) args = parser.parse_args() print(args) if args.outfile: with open(args.outfile, 'w') as f: for group_size in (len(args.featurefiles), 2): for group in IT.combinations(args.featurefiles, group_size): result = ''.join(sorted(reduce( args.operation, (set(open(filename)) for filename in group)))) f.write('{g}:\n{r}\n'.format(g=str(group), r=result)) You could call the script from the CLI like this: script.py -i file1 file2 file3 --op uniques -o /tmp/out References to tools used above: * [argparse](https://docs.python.org/2.7/library/argparse.html) * [itertools.combinations](https://docs.python.org/2/library/itertools.html#itertools.combinations) * [reduce](https://docs.python.org/2/library/functions.html#reduce) * [with-statement](http://effbot.org/zone/python-with-statement.htm) * [str format method](http://docs.python.org/library/string.html#format-string-syntax)
Strip HTML tags to get strings in python Question: I tried to get some strings from an HTML file with BeautifulSoup and everytime I work with it I get partial results. I want to get the strings in every li element/tag. So far I've been able to get everything in ul like this. #!/usr/bin/python from bs4 import BeautifulSoup page = open("page.html") soup = BeautifulSoup(page) source = soup.select(".sidebar li") And what I get is this: [<li class="first"> Def Leppard - Make Love Like A Man<span>Live</span> </li>, <li> Inxs - Never Tear Us Apart </li>, <li> Gary Moore - Over The Hills And Far Away </li>, <li> Linkin Park - Numb </li>, <li> Vita De Vie - Basul Si Cu Toba Mare </li>, <li> Nazareth - Love Hurts </li>, <li> U2 - I Still Haven't Found What I'm L </li>, <li> Blink 182 - All The Small Things </li>, <li> Scorpions - Wind Of Change </li>, <li> Iggy Pop - The Passenger </li>] I want to get only the strings from this. Answer: Use beautiful soups - .strings method. for string in soup.stripped_strings: print(repr(string)) from the docs: > If there’s more than one thing inside a tag, you can still look at just the > strings. Use the .strings generator: or > These strings tend to have a lot of extra whitespace, which you can remove > by using the .stripped_strings generator instead:
Partial fit multivariate SGDRegressor Question: I am currently trying to use the SGDRegressor from scikits learn to solve a multivariate target problem over a large dataset, X ~= (10^6,10^4). As such I am generating the design matrix (X) in parts with the following code, where each iteration produces a batch of size roughly (10^3,10^4): design = self.__iterX__(events) reglins = [linear_model.SGDRegressor(fit_intercept=True) for i in range(nTargets)] for X,times in design: for i in range(nTargets): reglins[i].partial_fit(X,y.ix[times].values[:,i]) However I get the following stack trace: File ".../Enthought/Canopy_64bit/User/lib/python2.7/site- packages/sklearn/linear_model/stochastic_gradient.py", line 841, in partial_fit coef_init=None, intercept_init=None) File ".../Enthought/Canopy_64bit/User/lib/python2.7/site-packages/sklearn/linear_model/stochastic_gradient.py", line 812, in _partial_fit sample_weight, n_iter) File ".../Enthought/Canopy_64bit/User/lib/python2.7/site-packages/sklearn/linear_model/stochastic_gradient.py", line 948, in _fit_regressor intercept_decay) File "sgd_fast.pyx", line 508, in sklearn.linear_model.sgd_fast.plain_sgd (sklearn/linear_model/sgd_fast.c:8651) ValueError: floating-point under-/overflow occurred. Looking around it seems that this can be cause by not normalizing X properly. I understand scikits learn has a variety of functions for this, however given that I generate X in blocks, is it enough to simply normalize each block or would I need to figure out a way to normalize whole columns at a time? Incidentally, is there a particular reason that the partial_fit function does not allow multivariate targets? Answer: You can fit one block and apply to others: from sklearn import preprocessing scaler = preprocessing.StandardScaler() x1 = scalar.fit_transform(X_block_1) xn = scalar.transform(X_block_n) You can choose other normalization methods [from this page](http://scikit- learn.org/stable/modules/preprocessing.html).
Python: How to (not) keep a COM-object persistent in memory after closing the parent application? Question: i am working on a (pretty big) Python/Tkinter-application (Python 2.7 under Windows 7) which (among many other things) calls Matlab via the COM-interface. The basic structure of the Matlab/COM-part is like this: import Tkinter import pythoncom import win32com.client class App( object ): def __init__( self, parent ): Tkinter.Button( root, text="Start Matlab", command=self.start_matlab ).grid() def start_matlab( self ): self.matlab = win32com.client.Dispatch( "Matlab.Application" ) root = Tkinter.Tk() App( root ) root.mainloop() The behaviour i observe with this simplified code is: Running the application and clicking the button creates a Matlab-Instance (opens a Matlab-Command window), and when closing the Tkinter application also that Matlab-window and the corresponding entry in the Task-Manager disappear. Repeating the procedure, Matlab is started afresh. However, when i do "the same" with my "real" application, the Matlab instance persists after closing my application and, moreover, when i restart the application and run the part which "starts" Matlab, it just retrieves and uses the instance which remained in memory after quitting the first sessiong of my app. Unfortunately, i am not able to isolate a reasonably small code example showing the latter behavior:( Does anybody have an idea what the reason for this is/could be? How can one control whether a COM-object is killed or persists in memory when the parent Python application which created it is closed? Answer: Here's how to explicitly remove the COM object, using Tkinter's protocol handler: import Tkinter import pythoncom import win32com.client class App( object ): def __init__( self, parent ): self.parent = parent #reference to root Tkinter.Button( root, text="Start Matlab", command=self.start_matlab ).grid() self.parent.protocol('WM_DELETE_WINDOW', self.closeAll) #protocol method def start_matlab( self ): self.matlab = win32com.client.Dispatch( "Matlab.Application" ) def closeAll(self): del self.matlab #delete the COM object self.parent.destroy() #close the window root = Tkinter.Tk() App( root ) root.mainloop() Reference: [Removing COM object from memory](https://mail.python.org/pipermail/python- win32/2008-February/007018.html) [More on protocols](http://effbot.org/tkinterbook/tkinter-events-and- bindings.htm)
python: how to use 'import' on character string variable? Question: I want to create a function which uses import, like the following: def test_module(module_name): try: import module_name except ImportError: print 'import '+module_name+' error' test_module('os') however, the function doesn't work because import seems not to recognize the string variable. are there any workarounds? thanks! Answer: `imported = __import__(module_name)` will work. Or you can use [`importlib.import_module`](https://docs.python.org/2/library/importlib.html#importlib.import_module). The difference is in convenience: in case of import like `module_name = 'top.lower'` `__import__` will return `top`, whereas `importlib.import_module` will return `lower`: >>> __import__('os.path') <module 'os' from nowhere> >>> importlib.import_module('os.path') <module 'ntpath' from nowhere>
Python 3.3 no module named MySQLdb, cymysql installed Question: Working through the introductory Django project tutorial on the official site. I have successfully installed the CyMySQL 0.5.5 connector through pip. The server status is "Running". For the command `python manage.py syncdb` this is what powershell returns. Could this have something to do with the DATABASES section of `settings.py` file having wrong parameters? : C:\Python33\lib\site-packages\win32\lib\pywintypes.py:39: DeprecationWarning: imp.get_suffixes() is deprecated; use constants defined on importlib.machinery instead for suffix_item in imp.get_suffixes(): Traceback (most recent call last): File "C:\Python33\lib\site-packages\django\db\backends\mysql\base.py", line 14, in <module> import MySQLdb as Database ImportError: No module named 'MySQLdb' During handling of the above exception, another exception occurred: Traceback (most recent call last): File "manage.py", line 10, in <module> execute_from_command_line(sys.argv) File "C:\Python33\lib\site-packages\django\core\management\__init__.py", line 399, in execute_from_command_line utility.execute() File "C:\Python33\lib\site-packages\django\core\management\__init__.py", line 392, in execute self.fetch_command(subcommand).run_from_argv(self.argv) File "C:\Python33\lib\site-packages\django\core\management\base.py", line 242, in run_from_argv self.execute(*args, **options.__dict__) File "C:\Python33\lib\site-packages\django\core\management\base.py", line 280, in execute translation.activate('en-us') File "C:\Python33\lib\site-packages\django\utils\translation\__init__.py", line 130, in activate return _trans.activate(language) File "C:\Python33\lib\site-packages\django\utils\translation\trans_real.py", line 188, in activate _active.value = translation(language) File "C:\Python33\lib\site-packages\django\utils\translation\trans_real.py", line 177, in translation default_translation = _fetch(settings.LANGUAGE_CODE) File "C:\Python33\lib\site-packages\django\utils\translation\trans_real.py", line 159, in _fetch app = import_module(appname) File "C:\Python33\Lib\importlib\__init__.py", line 90, in import_module return _bootstrap._gcd_import(name[level:], package, level) File "<frozen importlib._bootstrap>", line 1584, in _gcd_import File "<frozen importlib._bootstrap>", line 1565, in _find_and_load File "<frozen importlib._bootstrap>", line 1532, in _find_and_load_unlocked File "<frozen importlib._bootstrap>", line 584, in _check_name_wrapper File "<frozen importlib._bootstrap>", line 1022, in load_module File "<frozen importlib._bootstrap>", line 1003, in load_module File "<frozen importlib._bootstrap>", line 560, in module_for_loader_wrapper File "<frozen importlib._bootstrap>", line 868, in _load_module File "<frozen importlib._bootstrap>", line 313, in _call_with_frames_removed File "C:\Python33\lib\site-packages\django\contrib\admin\__init__.py", line 6, in <module> from django.contrib.admin.sites import AdminSite, site File "C:\Python33\lib\site-packages\django\contrib\admin\sites.py", line 4, in <module> from django.contrib.admin.forms import AdminAuthenticationForm File "C:\Python33\lib\site-packages\django\contrib\admin\forms.py", line 6, in <module> from django.contrib.auth.forms import AuthenticationForm File "C:\Python33\lib\site-packages\django\contrib\auth\forms.py", line 17, in <module> from django.contrib.auth.models import User File "C:\Python33\lib\site-packages\django\contrib\auth\models.py", line 48, in <module> class Permission(models.Model): File "C:\Python33\lib\site-packages\django\db\models\base.py", line 96, in __new__ new_class.add_to_class('_meta', Options(meta, **kwargs)) File "C:\Python33\lib\site-packages\django\db\models\base.py", line 264, in add_to_class value.contribute_to_class(cls, name) File "C:\Python33\lib\site-packages\django\db\models\options.py", line 124, in contribute_to_class self.db_table = truncate_name(self.db_table, connection.ops.max_name_length()) File "C:\Python33\lib\site-packages\django\db\__init__.py", line 34, in __getattr__ return getattr(connections[DEFAULT_DB_ALIAS], item) File "C:\Python33\lib\site-packages\django\db\utils.py", line 198, in __getitem__ backend = load_backend(db['ENGINE']) File "C:\Python33\lib\site-packages\django\db\utils.py", line 113, in load_backend return import_module('%s.base' % backend_name) File "C:\Python33\Lib\importlib\__init__.py", line 90, in import_module return _bootstrap._gcd_import(name[level:], package, level) File "C:\Python33\lib\site-packages\django\db\backends\mysql\base.py", line 17, in <module> raise ImproperlyConfigured("Error loading MySQLdb module: %s" % e) django.core.exceptions.ImproperlyConfigured: Error loading MySQLdb module: No module named 'MySQLdb' Answer: Please use django-cymysql and latest cymysql djang-cymysql <https://github.com/nakagami/django-cymysql/> cymysql 0.7.2 <https://pypi.python.org/pypi/cymysql/0.7.2> and use 'mysql_cymysql' ENGINE
Oauth using Birdy Python on Flask: Not able to figure out what to do with the Access Token Question: This is my code to fetch the tweets based on keyword. Here I am trying to Authenticate using Birdy Oauth API. But the problem is that I don't seem to understand why does it say that my token is expired when I enter the Token of my Application. **Please give specific feedback on what seems to be the issue here** import datetime from config import CONSUMER_KEY, CONSUMER_SECRET, SAVED_ACCESS_TOKEN #Saved access token is a list of containing my apps Access token and #Access token secret as its elements from birdy.twitter import AppClient from app import app from app import db from models import TweetInfo #Create an instance of appclient for the application client = AppClient(CONSUMER_KEY, CONSUMER_SECRET, SAVED_ACCESS_TOKEN) #Add the keywords here which need to be searched over Twitter QUERIES = ['#Vespa', '@Vespa'] #A method to fetch all the new entries for statuses #regarding the keywords queried that do not have an entry in the DataBase def get_new_tweets(): """Return number of tweets if any and save them in Database""" statuses = [] for query in QUERIES: response = client.api.search.tweets.get(q = query, count = 100) statuses += response.data.statuses latest_tweets = 0 for status in statuses: if not db.session.query(TweetInfo).filter(TweetInfo.domain_id == status.id_str).count(): #check whether a tweet is already present in the DataBase created_at = datetime.datetime.strptime(status.created_at, r"%a %b %d %H:%M:%S +0000 %Y") o = TweetInfo(tweet = status.text, posted_by = '{} ({})'.format(status.user.screen_name, status.user.followers_count), recorded_at = datetime.datetime.now(), occured_at = created_at, domain_id = status.id_str) latest_tweets += 1 db.session.add(o) db.session.commit() return latest_tweets Answer: The Access Token is only valid for some time. So you have to get a new one with each Connection. Birdy will save it automaticaly. Remember with this auth you can only read. Replace this #Create an instance of appclient for the application client = AppClient(CONSUMER_KEY, CONSUMER_SECRET, SAVED_ACCESS_TOKEN) With this client = AppClient(CONSUMER_KEY, CONSUMER_SECRET) access_token = client.get_access_token()
using pygame to stream over sockets in python error Question: i am working on with a webcam script i got of the internet in python and i am using pygame module the code is import socket import pygame import sys port=5014 #create pygame screen screen = pygame.display.set_mode((800,600),0) while True: s=socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.bind(("",port)) # server is available on the whole network by setting host to "" s.listen(1) connection, addr = s.accept() received = [] # loop .recv, it returns empty string when done, then transmitted data is completely received while True: recvd_data = connection.recv(1440021) if not recvd_data: break else: received.append(recvd_data) dataset = ''.join(received) image = pygame.image.fromstring(dataset,(800,600),"RGB") # convert received image from string #image = pygame.transform.scale(image,(800,600)) # scale image to 800*600 screen.blit(image,(0,0)) # "show image" on the screen pygame.display.update() # check for quit events for event in pygame.event.get(): if event.type == pygame.QUIT: pygame.quit() sys.exit() and the client code is import socket import pygame import pygame.camera import sys import time host = "localhost" port = 5014 pygame.init() pygame.camera.init() cam_list = pygame.camera.list_cameras() # list available cameras webcam = pygame.camera.Camera(cam_list[0],(800,600)) # use first camera in list and set resolution webcam.start() # start camera while True: image = webcam.get_image() # capture image data = pygame.image.tostring(image,"RGB") # convert captured image to string, use RGB color scheme #print sys.getsizeof(data) # in case somebody wants to know the size of the captured image # prepare for connection to server s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) # TCP is used s.connect((host, port)) s.sendall(data) s.close() time.sleep(0.1) the error i get on the server is Traceback (most recent call last): File "/root/Desktop/serv.py", line 29, in <module> image = pygame.image.fromstring(dataset,(800,600),"RGB") # convert received image from string ValueError: String length does not equal format and resolution size and the error i get on the client is Traceback (most recent call last): File "/root/Desktop/cli.py", line 28, in <module> s.sendall(data) File "/usr/lib/python2.7/socket.py", line 224, in meth return getattr(self._sock,name)(*args) socket.error: [Errno 104] Connection reset by peer does anyone know what could be wrong Answer: I was using the same code and getting a similar error, the solution was to lower the resolution of the webcam because mine could not handle the 800x600. I also changed the "server" and "client" so the weebcam server acts like the "socket server" try the following code, make sure that your video is correct, on my example "/dev/video0" yours could be different. Start the webcam server first. Webcam server: import socket import pygame import pygame.camera import sys import time port = 5000 pygame.init() serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) serversocket.bind(("",port)) serversocket.listen(1) pygame.camera.init() webcam = pygame.camera.Camera("/dev/video0",(320,240)) webcam.start() while True: connection, address = serversocket.accept() image = webcam.get_image() # capture image data = pygame.image.tostring(image,"RGB") # convert captured image to string, use RGB color scheme connection.sendall(data) time.sleep(0.1) connection.close() Client server: import socket import pygame import sys host = "10.0.0.13" port=5000 screen = pygame.display.set_mode((320,240),0) while True: clientsocket=socket.socket(socket.AF_INET, socket.SOCK_STREAM) clientsocket.connect((host, port)) received = [] # loop .recv, it returns empty string when done, then transmitted data is completely received while True: #print("esperando receber dado") recvd_data = clientsocket.recv(230400) if not recvd_data: break else: received.append(recvd_data) dataset = ''.join(received) image = pygame.image.fromstring(dataset,(320,240),"RGB") # convert received image from string screen.blit(image,(0,0)) # "show image" on the screen pygame.display.update() # check for quit events for event in pygame.event.get(): if event.type == pygame.QUIT: pygame.quit() sys.exit()
python csv replace listitem Question: i have following output from a csv file: word1|word2|word3|word4|word5|word6|01:12|word8 word1|word2|word3|word4|word5|word6|03:12|word8 word1|word2|word3|word4|word5|word6|01:12|word8 what i need to do is change the time string like this 00:01:12. my idea is to extract the list item [7] and add a "00:" as string to the front. import csv with open('temp', 'r') as f: reader = csv.reader(f, delimiter="|") for row in reader: fixed_time = (str("00:") + row[7]) begin = row[:6] end = row[:8] print begin + fixed_time +end get error message: TypeError: can only concatenate list (not "str") to list. i also had a look on this post. [how to change [1,2,3,4] to '1234' using python](http://stackoverflow.com/questions/2597932/how-to- change-1-2-3-4-to-1234-using-python/2597937#2597937) i neeed to know if my approach to soloution is the right way. maybe need to use split or anything else for this. thx for any help Answer: The line that's throwing the exception is print begin + fixed_time +end because `begin` and `end` are **both lists** and `fixed_time` is a string. Whenever you take a **slice** of a list (that's the `row[:6]` and `row[:8]` parts), a list is returned. If you just want to print it out, you can do print begin, fixed_time, end and you won't get an error. ### Corrected code: I'm opening a new file for writing (I'm calling it 'final', but you can call it whatever you want), and I'm just writing everything to it with the one modification. It's easiest to just change the one element of the list that has the line (`row[6] here`), and use `'|'.join` to write a pipe character between each column. import csv with open('temp', 'r') as f, open('final', 'w') as fw: reader = csv.reader(f, delimiter="|") for row in reader: # just change the element in the row to have the extra zeros row[6] = '00:' + row[6] # 'write the row back out, separated by | characters, and a new line. fw.write('|'.join(row) + '\n')
Nginx and Flask-socketio Websockets: Alive but not Messaging? Question: I've been having a bit of trouble getting Nginx to play nicely with the Python Flask-socketio library (which is based on gevent). Currently, since we're actively developing, I'm trying to get Nginx to just work as a proxy. For sending pages, I can get this to work, either by directly running the flask- socketio app, or by running through gunicorn. One hitch: the websocket messaging does not seem to work. The pages are successfully hosted and displayed. However, when I try to use the websockets, they do not work. They are alive enough that the websocket thinks it is connected, but they will not send a message. If I remove the Nginx proxy, they do work. Firefox gives me this error when I try to send a message: > Firefox can't establish a connection to the server at > ws:///socket.io/1/websocket/. Where web address is where the server is located and the unique id is just a bunch of randomish digits. It seems to be doing enough to keep the connection live (e.g., the client thinks it is connected), but can't send a message over the websocket. I have to think that the issue has to do with some part of the proxy, but am having mighty trouble debugging what the issue might be (in part because this is my first go-round with both Flask-socketIO and nginx). The configuration file I am using for nginx is: user <user name>; ## This is set to the user name for the remote SSH session worker_processes 5; events { worker_connections 1024; ## Default: 1024 } http { default_type application/octet-stream; log_format main '$remote_addr - $remote_user [$time_local] $status ' '"$request" $body_bytes_sent "$http_referer" ' '"$http_user_agent" "$http_x_forwarded_for"'; sendfile on; server_names_hash_bucket_size 128; # this seems to be required for some vhosts server { listen 80; server_name _; location / { proxy_pass http://localhost:8000; proxy_http_version 1.1; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection "upgrade"; proxy_set_header Host $host; } } } I made the config file as an amalgam of a general example and a websocket specific one, but trying to fiddle with it has not solved the issue. Also, I am using the werkzeug Proxy_Fix call on my Flask app.wsgi_app when I use it in wsgi mode. I've tried it with and without that, to no avail, however. If anyone has some insight, I will be all ears/eyes. Answer: I managed to fix this. The issues were not specific to flask-socketio, but they were specific to Ubuntu, NginX, and gevent-socketio. Two significant issues were present: 1. Ubuntu 12.04 has a truly ancient version of nginx (1.1.19 vs 1.6.x for stable versions). Why? Who knows. What we do know is that this version does not support websockets in any useful way, as 1.3.13 is [about the earliest](https://github.com/LearnBoost/socket.io/wiki/Nginx-and-Socket.io) you should be using. 2. By default, gevent-socketio expects your sockets to be at the location /socket.io . You can upgrade the whole HTTP connection, but I had some trouble getting that to work properly (especially after I threw SSL into the mix). 3. I fixed #1, but in fiddling with it I purged by nginx and apt-get installed... the default version of nginx on Ubuntu. Then, I was mysteriously confused as to why things worked even worse than before. Many .conf files valiantly lost their lives in this battle. If trying to debug websockets in this configuration, I would recommend the following steps: 1. Check your nginx version via 'nginx -v'. If it is anything less than 1.4, upgrade it. 2. Check your nginx.conf settings. You need to make sure the connection upgrades. 3. Check that your server IP and port match your nginx.conf reverse proxy. 4. Check that your client (e.g., socketio.js) connects to the right location and port, with the right protocol. 5. Check your blocked ports. I was on EC2, so you have to manually open 80 (HTTP) and 443 (SSL/HTTPS). Having just checked all of these things, there are takeaways. 1. Upgrading to the latest stable nginx version on Ubuntu ([full ref](https://www.digitalocean.com/community/articles/how-to-install-the-latest-version-of-nginx-on-ubuntu-12-10)) can be done by: sudo apt-get install python-software-properties sudo apt-get install software-properties-common sudo add-apt-repository ppa:nginx/stable sudo apt-get update sudo apt-get install nginx In systems like Windows, you can use an [installer](http://nginx.org/en/download.html) and will be less likely to get a bad version. 2. Many config files for this can be confusing, since nginx officially added sockets in about 2013, making earlier workaround configs obsolete. Existing config files don't tend to cover all the bases for nginx, gevent-socketio, and SSL together, but have them all separately ([Nginx Tutorial](https://chrislea.com/2013/02/23/proxying-websockets-with-nginx/), [Gevent-socketio](http://gevent-socketio.readthedocs.org/en/latest/server_integration.html), [Node.js with SSL](https://www.exratione.com/2013/06/websockets-over-ssl-with-nodejs-and-nginx/)). A config file for nginx 1.6 with flask-socketio (which wraps gevent-socketio) and SSL is: user <user account, probably optional>; worker_processes 2; error_log /var/log/nginx/error.log; pid /var/run/nginx.pid; events { worker_connections 1024; } http { include mime.types; default_type application/octet-stream; access_log /var/log/nginx/access.log; sendfile on; # tcp_nopush on; keepalive_timeout 3; # tcp_nodelay on; # gzip on; client_max_body_size 20m; index index.html; map $http_upgrade $connection_upgrade { default upgrade; '' close; } server { # Listen on 80 and 443 listen 80 default; listen 443 ssl; (only needed if you want SSL/HTTPS) server_name <your server name here, optional unless you use SSL>; # SSL Certificate (only needed if you want SSL/HTTPS) ssl_certificate <file location for your unified .crt file>; ssl_certificate_key <file location for your .key file>; # Optional: Redirect all non-SSL traffic to SSL. (if you want ONLY SSL/HTTPS) # if ($ssl_protocol = "") { # rewrite ^ https://$host$request_uri? permanent; # } # Split off basic traffic to backends location / { proxy_pass http://localhost:8081; # 127.0.0.1 is preferred, actually. proxy_redirect off; } location /socket.io { proxy_pass http://127.0.0.1:8081/socket.io; # 127.0.0.1 is preferred, actually. proxy_redirect off; proxy_buffering off; # Optional proxy_http_version 1.1; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection $connection_upgrade; } } } 3. Checking that your Flask-socketio is using the right port is easy. This is sufficient to work with the above: from flask import Flask, render_template, session, request, abort import flask.ext.socketio FLASK_CORE_APP = Flask(__name__) FLASK_CORE_APP.config['SECRET_KEY'] = '12345' # Luggage combination SOCKET_IO_CORE = flask.ext.socketio.SocketIO(FLASK_CORE_APP) @FLASK_CORE_APP.route('/') def index(): return render_template('index.html') @SOCKET_IO_CORE.on('message') def receive_message(message): return "Echo: %s"%(message,) SOCKET_IO_CORE.run(FLASK_CORE_APP, host=127.0.0.1, port=8081) 4. For a client such as socketio.js, connecting should be easy. For example: <script type="text/javascript" src="//cdnjs.cloudflare.com/ajax/libs/socket.io/0.9.16/socket.io.min.js"></script> <script type="text/javascript"> var url = window.location.protocol + document.domain + ':' + location.port, socket = io.connect(url); socket.on('message', alert); io.emit("message", "Test") </script> 5. Opening ports is really more of a [server-fault](http://serverfault.com/search?q=unblock%20port) or a [superuser](http://superuser.com/search?q=unblock%20port) issue, since it will depend a lot on your firewall. For Amazon EC2, see [here](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-network-security.html). 6. If trying all of this does not work, cry. Then return to the top of the list. Because you might just have accidentally reinstalled an older version of nginx.
Docusign: Python code not able to upload PDF formats Question: I have implemented embedded signing using python(Have followed the code given in `Docusign` samples). Everything works good with `.txt` files. Just any other format gives me an encoding error. UnicodeDecodeError: 'ascii' codec can't decode byte 0x9c in position 351: ordinal not in range(128) Code: filepath = os.path.join(settings.MEDIA_ROOT, documentName) fileContents = open(filepath, "r").read() requestBody = "\r\n\r\n--BOUNDARY\r\n" + \ "Content-Type: application/json\r\n" + \ "Content-Disposition: form-data\r\n" + \ "\r\n" + \ envelopeDef + "\r\n\r\n--BOUNDARY\r\n" + \ "Content-Type: text/plain\r\n" + \ "Content-Disposition: file; filename=\"test_doc.txt\"; documentId=1\r\n" + \ "\r\n" + \ fileContents + "\r\n" + \ "--BOUNDARY--\r\n\r\n" # append "/envelopes" to the baseUrl and use in the request url = baseUrl + "/envelopes"; headers = {'X-DocuSign-Authentication': AUTHENTICATION_STR, 'Content-Type': 'multipart/form-data; boundary=BOUNDARY', 'Accept': 'application/json'}; http = httplib2.Http() response, content = http.request(url, 'POST', headers=headers, body=requestBody) I tried encoding in UTF-8 import codecs fileContents = codecs.open(filepath,mode='r', encoding='utf-8').read() Still it doesnt help. I also tried changing the `Content-Type` to : `application/pdf` Can anyone suggest a way of doing it? # Docusign Answer: What is your terminal setting.... it should be UTF-8. Also, take a look at this [article](http://www.joelonsoftware.com/articles/Unicode.html) to get more clear picture about unicode. Try this: import sys reload(sys) sys.setdefaultencoding("utf-8") **EDIT:** Defining source code encoding also helps me a lot like : # -*- coding: utf-8 -*- Take a look at [PEP 0263](http://legacy.python.org/dev/peps/pep-0263/) docs
No Such Resource 404 error Question: I want to run index.html. so when I type localhost:8080 then index.html should be executed in browser. but its giving no such resource. I am specifying the entire path of index.html. please help me out.?? from twisted.internet import reactor from twisted.web.server import Site from twisted.web.static import File resource = File('/home/venky/python/twistedPython/index.html') factory = Site(resource) reactor.listenTCP(8000, factory) reactor.run() Answer: This is related to the difference between a URL ending with a slash and one without. It appears that Twisted considers a URL at the top level (like your `http://localhost:8000`) to include an implicit trailing slash (`http://localhost:8000/`). That means that the URL path includes an empty segment. Twisted then looks in the `resource` for a child named `''` (empty string). To make it work, add that name as a child: from twisted.internet import reactor from twisted.web.server import Site from twisted.web.static import File resource = File('/home/venky/python/twistedPython/index.html') resource.putChild('', resource) factory = Site(resource) reactor.listenTCP(8000, factory) reactor.run() Also, your question has port `8080` but your code has `8000`.
How can i print columns in same rows with different 'codes' using csv python Question: Here is my code.csv file: one,two,three 1,2,3 2,3,4 3,4,5 and code2.csv file: ,two,three ,2,3 ,3,4 ,4,5 this is my code.py file: import csv with open('code.csv', 'rb') as input, open('result.csv', 'wb') as output: reader = csv.DictReader(input) rows = [row for row in reader] writer = csv.writer(output, delimiter = ',') writer.writerow(["new_one", "new_two", "new_three"]) for row in rows: if 'two' in row: writer.writerow(['',row["two"]]) for row in rows: if 'one' in row: writer.writerow([row["one"]]) The problem is that output is printed in different rows: new_one,new_two,new_three ,2 ,3 ,4 1 2 3 How can I make the for row in rows: if 'one' in row: writer.writerow([row["one"]]) to be printed like this new_one,new_two,new_three 1,2 2,3 3,4 Without having to type it like this for row in rows: if 'one' in row and 'two' in row: writer.writerow([row["one"],row["two"]]) Now if i would have code2.csv instead of code.csv, the latter (`if 'one' in row and 'two' in row:`) would give me error "'one' not found". So I need to have something like maybe "`for row in rows[1]:`" or something. Obviously that doesn't work, but something similar? Answer: You **must** write row by row, not column by column. I think this should do it: for row in rows: writer.writerow([row.get("one", ""), row.get("two", "")])
Sorting a list of dates in Python Question: I have a list in python that is directories who's names are the date they were created; import os ConfigDir = "C:/Config-Archive/" for root, dirs, files in os.walk(ConfigDir): if len(dirs) == 0: # This directory has no subfolder ConfigListDir = root + "/../" # Step back up one directory ConfigList = os.listdir(ConfigListDir) print(ConfigList) ['01-02-2014', '01-03-2014', '01-08-2013', '01-09-2013', '01-10-2013'] I want the most recent directory which is that example is `01-03-2014`, the second in the list. The dates are DD-MM-YYYY. Can this be sorted using the lamba sort key or should I just take the plunge and write a simple sort function? Answer: You'd parse the date in a sorting key: from datetime import datetime sorted(ConfigList, key=lambda d: datetime.strptime(d, '%d-%m-%Y')) Demo: >>> from datetime import datetime >>> ConfigList = ['01-02-2014', '01-03-2014', '01-08-2013', '01-09-2013', '01-10-2013'] >>> sorted(ConfigList, key=lambda d: datetime.strptime(d, '%d-%m-%Y')) ['01-08-2013', '01-09-2013', '01-10-2013', '01-02-2014', '01-03-2014']
convert python sqlite db to hdf5 Question: A Pandas DataFrame can be converted to a hdf5 file like this; `df.to_hdf('test_store.hdf','test',mode='w')` I have an sqlite db file which has to be converted to a hdf5 file and then I would read the hdf5 file through pandas using `pd.read_hdf`. But first how do I convert a python sqlite db to a hdf5 file ? EDIT: I am aware of using the `.read_sql` method in pandas. But I would like to convert the db to hdf5 first. Answer: This is surprisingly simple: Use pandas! pandas supports [reading data directly from a SQL database](http://pandas.pydata.org/pandas-docs/stable/io.html#io-sql) into a DataFrame. Once you've got the DataFrame, you can do with it as you wish. Short example, taken [from the docs](http://pandas.pydata.org/pandas- docs/stable/io.html#io-sql): import sqlite3 from pandas.io import sql # Create your connection. cnx = sqlite3.connect('mydbfile.sqlite') # read the result of the SQL query into a DataFrame data = sql.read_sql("SELECT * FROM data;", cnx) # now you can write it into a HDF5 file data.to_hdf('test_store.hdf','test',mode='w')
3D plot with an 2D array python matplotlib Question: I have 2 1D arrays with the values of x and y, and also a 2D array with the values of z for each point where the columns correspond to the x values and the rows to the y values. Is there any way to get a plot_surface with this data? when I try to do it it returns me no plot. Here is the code: (calculate_R is a function I made for the program) x=np.arange(0,10,1) y=np.arange(0,1,0.2) lx= len(x) ly=len(y) z=np.zeros((lx,ly)) for i in range(lx): for j in range(ly): z[i,j]=calculate_R(y[j],x[i]) fig = plt.figure() ax = Axes3D(fig) x, y = np.meshgrid(x, y) ax.plot_surface(x, y, z, rstride=1, cstride=1, cmap='hot') Answer: You forgot to call [`plt.show()`](http://matplotlib.org/1.3.0/api/pyplot_api.html#matplotlib.pyplot.show) to display your plot. Note that you might be able to exploit numpy vectorization to speed up the calculation of `z`: import numpy as np import matplotlib.pyplot as plt from mpl_toolkits.mplot3d.axes3d import Axes3D x = np.arange(0,10,1) y = np.arange(0,1,0.2) xs, ys = np.meshgrid(x, y) # z = calculate_R(xs, ys) zs = xs**2 + ys**2 fig = plt.figure() ax = Axes3D(fig) ax.plot_surface(xs, ys, zs, rstride=1, cstride=1, cmap='hot') plt.show() Here, I used a simple function, since you didn't supply a fully working example.
How can I get a list like this [30,31,32,33,34,35] when i give "in between 30 and 35" to a python function Question: As I am not good in regular expression, please help me to get the define the method. I have a method which takes string as argument and returns a list 1. get_values("IN BETWEEN 30 AND 35") => [30,31,32,33,34,35] 2. get_values("(in between 35 and 40) and (in [56,57,58])") => [35,36,37,38,39,40,56,57,58] 3. get_values("(in between 30 and 35) and (IN BETWEEN 40 AND 45)") =>[30,31,32,33,34,35,40,41,42,43,44,45] These and their combinations are the possible cases Answer: This is a potential solution, but this should really be handled by properly parsing the SQL syntax using some kind of parser: import re def get_values(sql): sql = sql.upper() between_regex = '(\d+)\s+AND\s+(\d+)' ranges = [range(int(a), int(b)) for a, b in re.findall(between_regex, sql)] in_regex = '\[(.*)]' ranges += [[int(y) for y in x.split(',')] for x in re.findall(in_regex, sql)] return [x for r in ranges for x in r] print get_values("IN BETWEEN 30 AND 35") print get_values("(in between 35 and 40) and (in [56,57,58])") print get_values("(in between 30 and 35) and (IN BETWEEN 40 AND 45)") #[30, 31, 32, 33, 34] #[35, 36, 37, 38, 39, 56, 57, 58] #[30, 31, 32, 33, 34, 40, 41, 42, 43, 44]
Fast way to convert rgb to lab in python Question: Is there a quick way to convert RGB to LAB in Python3 using D50 sRGB? [Python-Colormath](https://github.com/gtaylor/python-colormath) too slow [skimage](http://scikit-image.org/docs/0.9.x/api/skimage.color.html#xyz2lab) use D65 Answer: For now, the white reference in skimage cannot be passed as a parameter (pull request welcome), but here is a workaround: from skimage import color color.colorconv.lab_ref_white = np.array([0.96422, 1.0, 0.82521]) lab = color.rgb2lab(image)
relative import from __init__.py file throws error Question: So I'm using a template set by a co-worker and as a newbie to python I may be missing something very obvious. The main directory has the init file which has a module I need for the main python file that generates the error. Co-worker used: from . import X Where X was the module, but when copying this (and a populated init file) to my own directory it generates this error: > ValueError: Attempted relative import in non-package From google and SO I gather that this is perfectly fine and logical so I'm wondering, as a newbie, what I've missed. Answer: You have to understand how Python handles modules. When you start the interpreter with a script, this script becomes the main module, with the matching name `__main__`. When using `import`, other modules are searched in the search path, that you can also access (and change) using `sys.path`. The first entry of `sys.path` is usually empty and stands for the current directory. A directory within the search path is a package if it contains a `__init__.py` file. Now, when you execute a script within a directory that contains an `__init__.py` file, this script will become `__main__` and the directory is not regarded as a package, as it is not in `sys.path`! For example, consider the following directory layout: root/ pkg/ __init__.py b.py c.py a.py When you run `python a.py` from the `root/` directory, you can import `pkg/` and use relative imports within this package (e.g., `from . import c` in `b.py` or `__init__.py`). When you run `python b.py` from the `pkg` directory, you cannot use relative imports since Python does not recognize `pkg` as a package: it is not in `sys.path`. For Python, `pkg` is an ordinary directory, no matter if it contains a `__init__.py`. The fully qualified name of `c.py` is just `c`, not `pkg.c`, so a relative `from . import c` won't work.
AttributeError: 'float' object has no attribute 'getLow' using Pyalgotrade in Python Question: I trying to write a Stochastic Oscillator in python using the list function in Pyalgotrade library. Pyalgotrade library is a Python library for backtesting stock trading strategies. Let’s say you have an idea for a trading strategy and you’d like to evaluate it with historical data and see how it behaves. PyAlgoTrade allows you to do so with minimal effort. The python code is like this: from pyalgotrade.tools import yahoofinance from pyalgotrade import strategy from pyalgotrade.barfeed import yahoofeed from pyalgotrade.technical import stoch from pyalgotrade import dataseries from pyalgotrade.technical import ma from pyalgotrade import technical from pyalgotrade.technical import highlow class MyStrategy(strategy.BacktestingStrategy): def __init__(self, feed, instrument): strategy.BacktestingStrategy.__init__(self, feed) self.__stoch = stoch.StochasticOscillator(feed[instrument].getCloseDataSeries(),20, dSMAPeriod=3, maxLen=3) self.__instrument = instrument def onBars(self, bars): bar = bars[self.__instrument] self.info("%s %s" % (bar.getClose(), self.__stoch[-1])) # Downdload then Load the yahoo feed from the CSV file yahoofinance.download_daily_bars('AAPL', 2013, 'aapl.csv') feed = yahoofeed.Feed() feed.addBarsFromCSV("AAPL", "aapl.csv") # Evaluate the strategy with the feed's bars. myStrategy = MyStrategy(feed, "AAPL") myStrategy.run() The error is like this,including all the trace back. Traceback (most recent call last): File "/Users/johnhenry/Desktop/simple_strategy.py", line 47, in <module> myStrategy.run() File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pyalgotrade/strategy/__init__.py", line 519, in run self.__dispatcher.run() File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pyalgotrade/dispatcher.py", line 102, in run eof, eventsDispatched = self.__dispatch() File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pyalgotrade/dispatcher.py", line 90, in __dispatch if self.__dispatchSubject(subject, smallestDateTime): File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pyalgotrade/dispatcher.py", line 68, in __dispatchSubject ret = subject.dispatch() is True File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pyalgotrade/feed/__init__.py", line 101, in dispatch dateTime, values = self.getNextValuesAndUpdateDS() File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pyalgotrade/feed/__init__.py", line 85, in getNextValuesAndUpdateDS ds.appendWithDateTime(dateTime, value) File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pyalgotrade/dataseries/bards.py", line 49, in appendWithDateTime self.__closeDS.appendWithDateTime(dateTime, value.getClose()) File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pyalgotrade/dataseries/__init__.py", line 134, in appendWithDateTime self.getNewValueEvent().emit(self, dateTime, value) File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pyalgotrade/observer.py", line 59, in emit handler(*args, **kwargs) File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pyalgotrade/technical/__init__.py", line 89, in __onNewValue newValue = self.__eventWindow.getValue() File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pyalgotrade/technical/stoch.py", line 60, in getValue lowestLow, highestHigh = get_low_high_values(self.__barWrapper, self.getValues()) File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pyalgotrade/technical/stoch.py", line 42, in get_low_high_values lowestLow = barWrapper.getLow(currBar) File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pyalgotrade/technical/stoch.py", line 31, in getLow return bar_.getLow(self.__useAdjusted) AttributeError: 'float' object has no attribute 'getLow' Answer: You're not building the StochasticOscillator properly. You passing the close dataseries, and as explained in the doc, you need to pass in the bar dataseries: self.__stoch = stoch.StochasticOscillator(feed[instrument], 20, dSMAPeriod=3, maxLen=3)
Implementing Facebook FQL in Python Question: It will probably be obvious soon enough, but I am new to coding and StackOverflow -- apologies if I come off as a bit oblivious. I have been trying to query Facebook with FQL out of a function on my views.py page in a Django app. I did have a working solution utilizing the Facebook Graph API, but it was ultimately a poor solution since I am aiming to retrieve the user’s newsfeed. While there are a number of answers relating to Facebook FQL in PHP, there are no explicit examples in Python. Instead, most of the questions are just related to the syntax of the query, and not how to actually integrate it into an actual function. The query I am looking to make is: SELECT post_id, app_id, source_id, updated_time, filter_key, attribution, message, action_links, likes, permalink FROM stream WHERE filter_key IN (SELECT filter_key FROM stream_filter WHERE uid = me() AND type = 'newsfeed’) As I understand, the best way to make this request is using Requests but frankly, I am just looking for a working solution. I considered posting some of my non-working code up here, but it has pretty much spiraled into a mess. Any help or direction is greatly appreciated! **_UPDATE_** Just wanted to document where I am at, with Sohan Jain's help, I've gotten to this point: def get_fb_post(request): user_id = UserSocialAuth.objects.get(user=request.user) api = facebook.GraphAPI(user_id.tokens) # response gets deserialized into a python object response = api.fql('''SELECT post_id, app_id, source_id, updated_time, filter_key, attribution, message, action_links, likes, permalink FROM stream WHERE filter_key IN (SELECT filter_key FROM stream_filter WHERE uid = me() AND type = 'newsfeed')''') print(response) data = {'profile': '...something...' } # what should be going in here? return HttpResponse(json.dumps(data), mimetype='application/json') In PyCharm I am getting the following (link to image if you prefer: <http://i.stack.imgur.com/8sZDF.png>): /Library/Python/2.7/site-packages/facebook.py:52: DeprecationWarning: django.utils.simplejson is deprecated; use json instead. from django.utils import simplejson as json In my browser I am getting this(image link again: <http://i.stack.imgur.com/njXo8.png>): GraphAPIError at /fbpost/ I am not sure how to fix the DeprecationWarning. I tried at the top of the file putting "from django.utils import simplejson as json" but that didn't work (I thought it was probably a bit too simplistic, but worth a shot). If I replace the query with this: response = api.fql("SELECT name, type, value, filter_key FROM stream_filter WHERE uid = me()") I do get a very long response that looks like this: [{u'filter_key': u'nf', u'type': u'newsfeed', u'name': u'News Feed', u'value': None}, {u'filter_key'... ...}] It goes on and on and does appear to be returning valid information. Answer: I have figured out how to get a response, the code looks something like this: from facepy import GraphAPI def get_fb_post(request): user_id = UserSocialAuth.objects.get(user=request.user) access_token = user_id.tokens graph = GraphAPI(access_token) data = graph.fql('''SELECT post_id, app_id, source_id, updated_time, filter_key, attribution, message, action_links, likes, permalink FROM stream WHERE filter_key IN (SELECT filter_key FROM stream_filter WHERE uid = me() AND type = 'newsfeed')''') return HttpResponse(json.dumps(data), mimetype='application/json') This is returning the information that I was looking for, which looks something like this: {u'data': [{u'filter_key': u'nf', u'permalink': u'facebook-link', u'attribution': None, u'app_id': u'123456789', u'updated_time': 1398182407, u'post_id': u'1482173147_104536679665087666', u'likes': ...etc, etc, etc.... Now, I am just going to try and randomize the displayed post by randomly iterating through the JSON -- granted, this is outside of the scope of my question here. Thanks to those who helped.
I made a copy of a working Django poll, however i did something wrong, because my poll does not work Question: I am trying to post a value to my database. I have been looking for a long time now at a working poll app, but i cannot seem to get my poll working. Hereunder the parts used by the poll app where somewhere the error must be. Thanks in advance for any help. The error i get when i dont make a choice for the poll is: **NoReverseMatch at /wedding/2/vote/ Reverse for 'vote' with arguments '('',)' and keyword arguments '{}' not found. 1 pattern(s) tried: [u'wedding/(?P\d+)/vote/$']** The error i get when i do make a choice for the poll is: **ValueError at /wedding/2/vote/ invalid literal for int() with base 10: ''** urls.py from django.conf.urls import patterns, url from wedding import views urlpatterns = patterns('', url(r'^$', views.IndexView.as_view(), name='index'), url(r'^(?P<pk>\d+)/$', views.DetailView.as_view(), name='detail'), url(r'^(?P<pk>\d+)/results/$', views.ResultsView.as_view(), name='results'), url(r'^(?P<invitee_id>\d+)/vote/$', views.vote, name='vote'), ) views.py from django.shortcuts import render, get_object_or_404 from django.http import HttpResponseRedirect, HttpResponse from django.core.urlresolvers import reverse from django.views import generic from django.template import RequestContext, loader # Create your views here. from wedding.models import Invitee, Invitee_extra class IndexView(generic.ListView): template_name = 'wedding/index.html' context_object_name = 'party_list' def get_queryset(self): """Return the party names""" return Invitee.objects.all().order_by('-party_name')[:5] class DetailView(generic.DetailView): model = Invitee template_name = 'wedding/detail.html' class ResultsView(generic.DetailView): model = Invitee template_name = 'wedding/results.html' def vote(request, invitee_id): p = get_object_or_404(Invitee, pk=invitee_id) try: selected_choice = p.invitee_extra_set.get(pk=request.POST['choice']) except (KeyError, Invitee_extra.DoesNotExist): # Redisplay the poll voting form. return render(request, 'wedding/detail.html', { 'wedding': p, 'error_message': "You didn't select a attendance.", }) else: selected_choice.attend += 1 selected_choice.save() # Always return an HttpResponseRedirect after successfully dealing # with POST data. This prevents data from being posted twice if a # user hits the Back button. return HttpResponseRedirect(reverse('details:results', args=(p.id,))) details.html <h1>name: {{ invitee.party_name }} id: {{ invitee.id }} </h1> {% if error_message %}<p><strong>{{ error_message }}</strong></p>{% endif %} <form action="{% url 'wedding:vote' invitee.id %}" method="post"> {% csrf_token %} {% for guests in invitee.invitee_extra_set.all %} <input type="radio" name="choice" id="choice{{ forloop.counter }}" value="{{ choice.id }}" /> <label for="choice{{ forloop.counter }}">{{ guests.guest }}</label><br /> {% endfor %} <input type="submit" value="Update gegevens" /> </form> models.py from django.db import models # Create your models here. class Invitee(models.Model): party_name = models.CharField(max_length=50) created_at = models.DateTimeField(auto_now_add=True) updated_at = models.DateTimeField(auto_now=True) def __unicode__(self): # Python 3: def __str__(self): return self.party_name class Invitee_extra(models.Model): invitee = models.ForeignKey(Invitee) guest = models.CharField(max_length=50) attend = models.IntegerField(default=0) def __unicode__(self): # Python 3: def __str__(self): return self.invitee Full traceback when i do select a radiobutton Environment: Request Method: POST Request URL: http://127.0.0.1:8000/wedding/2/vote/ Django Version: 1.6.2 Python Version: 2.7.5 Installed Applications: ('django.contrib.admin', 'django.contrib.auth', 'django.contrib.contenttypes', 'django.contrib.sessions', 'django.contrib.messages', 'django.contrib.staticfiles', 'wedding', 'food', 'polls') Installed Middleware: ('django.contrib.sessions.middleware.SessionMiddleware', 'django.middleware.common.CommonMiddleware', 'django.middleware.csrf.CsrfViewMiddleware', 'django.contrib.auth.middleware.AuthenticationMiddleware', 'django.contrib.messages.middleware.MessageMiddleware', 'django.middleware.clickjacking.XFrameOptionsMiddleware') Traceback: File "/Library/Python/2.7/site-packages/django/core/handlers/base.py" in get_response 114. response = wrapped_callback(request, *callback_args, **callback_kwargs) File "/Users/patrick/python/mysite/wedding/views.py" in vote 28. selected_choice = p.invitee_extra_set.get(pk=request.POST['choice']) File "/Library/Python/2.7/site-packages/django/db/models/manager.py" in get 151. return self.get_queryset().get(*args, **kwargs) File "/Library/Python/2.7/site-packages/django/db/models/query.py" in get 298. clone = self.filter(*args, **kwargs) File "/Library/Python/2.7/site-packages/django/db/models/query.py" in filter 590. return self._filter_or_exclude(False, *args, **kwargs) File "/Library/Python/2.7/site-packages/django/db/models/query.py" in _filter_or_exclude 608. clone.query.add_q(Q(*args, **kwargs)) File "/Library/Python/2.7/site-packages/django/db/models/sql/query.py" in add_q 1198. clause = self._add_q(where_part, used_aliases) File "/Library/Python/2.7/site-packages/django/db/models/sql/query.py" in _add_q 1234. current_negated=current_negated) File "/Library/Python/2.7/site-packages/django/db/models/sql/query.py" in build_filter 1125. clause.add(constraint, AND) File "/Library/Python/2.7/site-packages/django/utils/tree.py" in add 104. data = self._prepare_data(data) File "/Library/Python/2.7/site-packages/django/db/models/sql/where.py" in _prepare_data 79. value = obj.prepare(lookup_type, value) File "/Library/Python/2.7/site-packages/django/db/models/sql/where.py" in prepare 352. return self.field.get_prep_lookup(lookup_type, value) File "/Library/Python/2.7/site-packages/django/db/models/fields/__init__.py" in get_prep_lookup 369. return self.get_prep_value(value) File "/Library/Python/2.7/site-packages/django/db/models/fields/__init__.py" in get_prep_value 613. return int(value) Exception Type: ValueError at /wedding/2/vote/ Exception Value: invalid literal for int() with base 10: '' and the fulltraceback if i dont make a choice: Environment: Request Method: POST Request URL: http://127.0.0.1:8000/wedding/1/vote/ Django Version: 1.6.2 Python Version: 2.7.5 Installed Applications: ('django.contrib.admin', 'django.contrib.auth', 'django.contrib.contenttypes', 'django.contrib.sessions', 'django.contrib.messages', 'django.contrib.staticfiles', 'wedding', 'food', 'polls') Installed Middleware: ('django.contrib.sessions.middleware.SessionMiddleware', 'django.middleware.common.CommonMiddleware', 'django.middleware.csrf.CsrfViewMiddleware', 'django.contrib.auth.middleware.AuthenticationMiddleware', 'django.contrib.messages.middleware.MessageMiddleware', 'django.middleware.clickjacking.XFrameOptionsMiddleware') Template error: In template /Users/patrick/python/mysite/wedding/templates/wedding/detail.html, error at line 5 Reverse for 'vote' with arguments '('',)' and keyword arguments '{}' not found. 1 pattern(s) tried: [u'wedding/(?P<invitee_id>\\d+)/vote/$'] 1 : <h1>name: {{ invitee.party_name }} id: {{ invitee.id }} </h1> 2 : 3 : {% if error_message %}<p><strong>{{ error_message }}</strong></p>{% endif %} 4 : 5 : <form action=" {% url 'wedding:vote' invitee.id %} " method="post"> 6 : {% csrf_token %} 7 : {% for guests in invitee.invitee_extra_set.all %} 8 : <input type="radio" name="choice" id="choice{{ forloop.counter }}" value="{{ choice.id }}" /> 9 : <label for="choice{{ forloop.counter }}">{{ guests.guest }}</label><br /> 10 : {% endfor %} 11 : <input type="submit" value="Update gegevens" /> 12 : </form> Traceback: File "/Library/Python/2.7/site-packages/django/core/handlers/base.py" in get_response 114. response = wrapped_callback(request, *callback_args, **callback_kwargs) File "/Users/patrick/python/mysite/wedding/views.py" in vote 33. 'error_message': "You didn't select a attendance.", File "/Library/Python/2.7/site-packages/django/shortcuts/__init__.py" in render 53. return HttpResponse(loader.render_to_string(*args, **kwargs), File "/Library/Python/2.7/site-packages/django/template/loader.py" in render_to_string 169. return t.render(context_instance) File "/Library/Python/2.7/site-packages/django/template/base.py" in render 140. return self._render(context) File "/Library/Python/2.7/site-packages/django/template/base.py" in _render 134. return self.nodelist.render(context) File "/Library/Python/2.7/site-packages/django/template/base.py" in render 840. bit = self.render_node(node, context) File "/Library/Python/2.7/site-packages/django/template/debug.py" in render_node 78. return node.render(context) File "/Library/Python/2.7/site-packages/django/template/defaulttags.py" in render 447. six.reraise(*exc_info) File "/Library/Python/2.7/site-packages/django/template/defaulttags.py" in render 433. url = reverse(view_name, args=args, kwargs=kwargs, current_app=context.current_app) File "/Library/Python/2.7/site-packages/django/core/urlresolvers.py" in reverse 509. return iri_to_uri(resolver._reverse_with_prefix(view, prefix, *args, **kwargs)) File "/Library/Python/2.7/site-packages/django/core/urlresolvers.py" in _reverse_with_prefix 429. (lookup_view_s, args, kwargs, len(patterns), patterns)) Exception Type: NoReverseMatch at /wedding/1/vote/ Exception Value: Reverse for 'vote' with arguments '('',)' and keyword arguments '{}' not found. 1 pattern(s) tried: [u'wedding/(?P<invitee_id>\\d+)/vote/$'] Answer: In your vote view, if the submission is not valid, you re-render the template but you don't pass the Invitee to it - or rather you do, but you call it `wedding` rather than `invitee`. So when the template tries to calculate the URL of the vote submission for the invitee, it can't find the if value to use. You need to be sure to pass the data with the correct names. Note this would have been easier to debug if you'd provided more information about the error, such as the full traceback and what you did leading up to it.
How to obtain random access of a gzip compressed file Question: According to [this FAQ on zlib.net](http://www.zlib.net/zlib_faq.html#faq28) it is possible to: > access data randomly in a compressed stream I know about the module Bio.bgzf of [Biopyton 1.60](http://news.open- bio.org/news/2012/06/biopython-1-60-released/), which: > supports reading and writing BGZF files (Blocked GNU Zip Format), a variant > of GZIP with efficient random access, most commonly used as part of the BAM > file format and in tabix. This uses Python’s zlib library internally, and > provides a simple interface like Python’s gzip library. But for my use case I don't want to use that format. Basically I want something, which emulates the code below: import gzip large_integer_new_line_start = 10**9 with gzip.open('large_file.gz','rt') as f: f.seek(large_integer_new_line_start) but with the efficiency offered by the native zlib.net to provide random access to the compressed stream. How do I leverage that random access capability in Python? Answer: I gave up on doing random access on a gzipped file using Python. Instead I converted my gzipped file to a block gzipped file with a [block compression/decompression utility](http://samtools.sourceforge.net/tabix.shtml) on the command line: zcat large_file.gz | bgzip > large_file.bgz Then I used [BioPython](http://biopython.org/) and tell to get the virtual_offset of line number 1 million of the bgzipped file. And then I was able to rapidly seek the virtual_offset afterwards: from Bio import bgzf file='large_file.bgz' handle = bgzf.BgzfReader(file) for i in range(10**6): handle.readline() virtual_offset = handle.tell() line1 = handle.readline() handle.close() handle = bgzf.BgzfReader(file) handle.seek(virtual_offset) line2 = handle.readline() handle.close() assert line1==line2 I would like to also point to the [SO answer by Mark Adler](http://stackoverflow.com/a/14242594/778533) here on [examples/zran.c](https://github.com/madler/zlib/blob/master/examples/zran.c) in the [zlib](http://zlib.net/) distribution.
Python module equivalent to the unix command "fmt"? Question: There is some module with similar functionality to the unix command ["fmt"](http://www.openbsd.org/cgi- bin/man.cgi?query=fmt&apropos=0&sektion=0&manpath=OpenBSD%20Current&arch=i386&format=html)?. `fmt` is pretty intelligent reflowing text and I would like to use something similar with some big strings. Answer: import textwrap with open('long_text.txt', 'r') as f: long_text = f.read() # Get a list of wrapped lines (default width 70) long_text_lines = textwrap.wrap(long_text) # Get a single string containing the wrapped text # Same as: "\n".join(textwrap.wrap(long_text, ...)) long_text_string = textwrap.fill(long_text)
Python Tkinter: obtain tree node information Question: Python 2.7 Linux I am only using idlelib.TreeWidget to create a tree in Tkinter.Canvas, nothing else. How do I go about getting the information of the selected tree node (eg. name)? I need to access this information later. I am able to call a function when the Canvas is selected / double-clicked, but not sure how with the tree nodes: self.canvas.bind('<Double-Button-1>', self.onSave) Please run the following code (Note that there are 2 trees, 1 tree in each Canvas): from Tkinter import Tk, Frame, BOTH, Canvas from xml.dom.minidom import parseString from idlelib.TreeWidget import TreeItem, TreeNode class DomTreeItem(TreeItem): def __init__(self, node): self.node = node def GetText(self): node = self.node if node.nodeType == node.ELEMENT_NODE: return node.nodeName elif node.nodeType == node.TEXT_NODE: return node.nodeValue def IsExpandable(self): node = self.node return node.hasChildNodes() def GetSubList(self): parent = self.node children = parent.childNodes prelist = [DomTreeItem(node) for node in children] itemlist = [item for item in prelist if item.GetText().strip()] return itemlist data = ''' <angel> <digital_core> <radio_top>d</radio_top> <uart_top>e</uart_top> </digital_core> <digital_core> <c>f</c> </digital_core> </angel> ''' class Application(Frame): def __init__(self, parent): Frame.__init__(self, parent, background = "white") self.parent = parent # Maximize window self.screenWidth = self.parent.winfo_screenwidth() - 5 self.screenHeight = self.parent.winfo_screenheight() - 110 self.parent.geometry('%dx%d+%d+%d' % (self.screenWidth, self.screenHeight, 0, 0)) self.parent.resizable(0, 0) dom = parseString(data) item = DomTreeItem(dom.documentElement) self.canvas = Canvas(self, bg = "cyan") self.canvas.grid(column = 0, row = 0, rowspan = 2, sticky = 'NSWE', padx = 5, pady = 5) node = TreeNode(self.canvas, None, item) node.update() self.canvas2 = Canvas(self, bg = "yellow") self.canvas2.grid(column = 1, row = 0, rowspan = 2, sticky = 'NSWE', padx = 5, pady = 5) node2 = TreeNode(self.canvas2, None, item) node2.update() parent.configure(bg = "black") self.pack(fill = BOTH, expand = True, padx = 20, pady = 20) def main(): root = Tk() Application(root) root.mainloop() if __name__ == '__main__': main() Answer: The most direct approach I have seen is accessing the fields of the `TreeNode` to retrieve content passed into the `TreeNode` constructor. For instance, node.parent node.canvas node.item To get the text from the `DomTreeItem`, you can do node.item.GetText() You can also get additional information by looking at the methods in dir(node.item)
Pythonic way to extract first line of a tabular file to a list Question: This is a function that takes the tabular file as input and return the first row as list: def firstline_to_list(fvar): """ Input tab separated file. Output first row as list. """ import csv lineno = 0 with open(fvar, 'r') as tsvfile: tabreader = csv.reader(tsvfile, delimiter='\t') for row in tabreader: lineno += 1 if lineno == 1: return row break Is there a better way to do it than this clunky code of mine? Answer: Just replace your for loop with a single call of `next` on the iterator `tabreader`. In python 2.7, this should be `tabreader.next()`, and in python 3, I think it's `next(tabreader)`. You might also want to wrap the call in `try except` block for `StopIteration` exception, just in case the file is empty. So putting everything together, here's version that's compatible with python 2 and 3: def firstline_to_list(fvar): """ Input tab separated file. Output first row as list. """ import csv, sys with open(fvar, 'r') as tsvfile: tabreader = csv.reader(tsvfile, delimiter='\t') try: if sys.version > '3': result = next(tabreader) else: result = tabreader.next() except StopIteration: result = None return result
python types in list during comprehension Question: I have a sql query string such as the following: intro text, id int, description varchar(50) I am trying to create a string of types, with the goal of finding pieces of text that do not match the types defined in the sql schema. The way I am extracting the types from the sql text is as follows: types = [re.sub('[^a-zA-Z]','',x.split()[1]) for x in schema] types = [re.sub('varchar',types.StringType,x) for x in types] types = [re.sub('text',types.StringType,x) for x in types] types = [re.sub('bigint',types.IntType,x) for x in types] types = [re.sub('decimal',types.IntType,x) for x in types] However the interpreter complains that types = [re.sub('varchar',types.StringTypes,x) for x in types] AttributeError: 'list' object has no attribute 'StringTypes' A SSCCE With the following schema file intro text, id int, description varchar(50) and code (note, with fix as suggested by oscar below, but now with other error) import csv import sys import re import types sch = open(sys.argv[1], "rb") #--------------------------------- # read schema #--------------------------------- with sch as f: schema = f.read().splitlines() #--------------------------------- # extract schema types #--------------------------------- foundtypes = [re.sub('[^a-zA-Z]','',x.split()[1]) for x in schema] foundtypes = [re.sub('varchar',str,x) for x in foundtypes] foundtypes = [re.sub('text',str,x) for x in foundtypes] foundtypes = [re.sub('int',int,x) for x in foundtypes] foundtypes = [re.sub('bigint',int,x) for x in foundtypes] foundtypes = [re.sub('decimal',int,x) for x in foundtypes] print foundtypes I am using Python 2.7.5 thank you Answer: You overwrote the binding (see: [variable shadowing](http://en.wikipedia.org/wiki/Variable_shadowing)) to the `types` [module](https://docs.python.org/2/library/types.html), in this line: types = [re.sub('[^a-zA-Z]','',x.split()[1]) for x in schema] After that, `types` is no longer pointing to the module, but to a list. Just use another name in all the assignments: my_types = [re.sub('[^a-zA-Z]','',x.split()[1]) for x in schema] my_types = [re.sub('varchar',types.StringType,x) for x in my_types] my_types = [re.sub('text',types.StringType,x) for x in my_types] my_types = [re.sub('bigint',types.IntType,x) for x in my_types] my_types = [re.sub('decimal',types.IntType,x) for x in my_types] **UPDATE** I think you overdesigned the solution, except for the first line this is not a good fit for using regular expressions. A simple `if-elif-else` will work just fine: def transform(typestr): if typestr in ('varchar', 'text'): return types.StringType elif typestr in ('int', 'bigint', 'decimal'): return types.IntType else: return None my_types = [re.sub(r'[^a-zA-Z]', '', x.split()[1]) for x in schema] [transform(x) for x in my_types] => [<type 'str'>, <type 'int'>, <type 'str'>]
python SIP log file processing Question: i have a sniff/log file for VoIP/SIP generated by python scapy in format time | src | srcport | dst | dstport | payload the sniff python script looks like this: ## Import Scapy module from scapy.all import * import sys sys.stdout = open('data.txt', 'w') pkts = sniff(filter="udp and port 5060 and not port 22", count=0,prn=lambda x:x.sprintf("%sent.time% | %IP.src% | %IP.sport% | %IP.dst% | %IP.dport% | Payload {Raw:%Raw.load%\n}")) each packet in one line and each line can have different size depends on SIP message type (Register, 200 OK, Invite, Notify and so on...) What i would like to get from the file are fields `time, src, srcport, dst, dstport` and from `Payload` type (just right after Payload) of `SIP message, From, To, Call-iD, Contact` and the whole payload and then prepare these to insert into MySQL database. 1st msg: 07:57:01.894990 | 192.168.1.10 | 5060 | 192.168.1.1 | 5060 | Payload 'INVITE sip:[email protected] SIP/2.0\r\nVia: SIP/2.0/UDP 192.168.1.10:5060;rport;branch=z9hG4bK-9cbb0ba8\r\nRoute: <sip:192.168.1.1:5060;lr>\r\nFrom: "test-311" <sip:[email protected]>;tag=3d13bd6f\r\n To: <sip:[email protected]>\r\nCall-ID: [email protected]\r\nCSeq: 1 INVITE\r\n Contact: "test-311" <sip:[email protected]:5060;transport=UDP>\r\nMax-Forwards: 70\r\n Supported: 100rel,replaces\r\nAllow: ACK, BYE, CANCEL, INFO, INVITE, OPTIONS, NOTIFY, PRACK, REFER, UPDATE, MESSAGE\r\nContent-Type: application/sdp\r\nContent-Length: 276\r\n\r\nv=0\r\no=- 3506863524 285638052 IN IP4 192.168.1.10\r\ns=-\r\nc=IN IP4 192.168.1.10\r\nt=0 0\r\nm=audio 8000 RTP/AVP 8 0 18 101\r\nc=IN IP4 192.168.1.10\r\na=rtpmap:8 PCMA/8000\r\na=rtpmap:0 PCMU/8000\r\na=rtpmap:18 G729/8000\r\na=rtpmap:101 telephone-event/8000\r\na=fmtp:101 0-15\r\na=ptime:20\r\n' 2nd msg: 07:57:01.902618 | 192.168.1.1 | 5060 | 192.168.1.10 | 5060 | Payload 'SIP/2.0 100 Trying\r\nVia: SIP/2.0/UDP 192.168.1.10:5060;received=192.168.1.10;branch=z9hG4bK-9cbb0ba8;rport=5060\r\nFrom: "test-311" <sip:[email protected]>;tag=3d13bd6f\r\nTo: <sip:[email protected]>\r\nCall-ID: [email protected]\r\nCSeq: 1 INVITE\r\n\r\n' I have tried to read line by line and split but I do not know how to split and take data from payload part. Any help is more then welcome. Answer: Well, you can enter the data into mysql straight from this program too; it might very well be the easiest approach. from scapy.all import * import sys # connect to mysql connection = ... def insert_into_mysql(packet): # now you can use packet.src, packet.sport, packet.dst, packet.dport, and # I believe packet['Raw'].load connection.execute(...) # to not print the packet return None # to print the packet return x.sprintf("%sent.time% | %IP.src% | %IP.sport% | %IP.dst% | %IP.dport% | Payload {Raw:%Raw.load%\n}" pkts = sniff(filter="udp and port 5060", count=0, store=0, prn=insert_into_mysql) But if you need to use the existing log, I think you need to use: for line in open('log.txt'): sent_time, src, sport, dst, dport, payload = line.split(' | ', 6) payload = payload.replace('Payload ', '') # to get the unquoted payload, I'd guess (can't test SIP though) from ast import literal_eval payload = literal_eval(payload)
unable to post tweet on python 3.4 and twitter-1.14.2 api Question: from twitter.api import Api Api = twitter.api(consumer_key='[gdgfdfhgfuff] ', consumer_secret='[jhhjf] ', access_token_key=' [jhvhvvhjvhvhvh]', access_token_secret='[hvghgvvh] ') friends=Api.PostUpdate("First Tweet from PYTHON APP ") error given TTraceback (most recent call last): File "<pyshell#5>", line 1, in <module> from twitter.api import Api ImportError: cannot import name 'Api' I am using python 3.4 and twitter-1.14.2 api Answer: Replace `from twitter.api import Api` with `from twitter.api import Twitter` There is no class or method in [`twitter.api`](https://github.com/sixohsix/twitter/blob/master/twitter/api.py) called `Api`
Strange poco reactor's notifications Question: I have code that implements Poco SocketReactor, as described from Echo example. class TSPConnectionHandler { public: TSPConnectionHandler(const StreamSocket& socket, SocketReactor& reactor) : _socket(socket), _reactor(reactor) { _reactor.addEventHandler(_socket, Poco::NObserver<TSPConnectionHandler, ReadableNotification>(*this, &TSPConnectionHandler::onSocketReadable)); _reactor.addEventHandler(_socket, Poco::NObserver<TSPConnectionHandler, WritableNotification>(*this, &TSPConnectionHandler::onSocketWritable)); _reactor.addEventHandler(_socket, Poco::NObserver<TSPConnectionHandler, ShutdownNotification>(*this, &TSPConnectionHandler::onSocketShutdown)); _reactor.addEventHandler(_socket, Poco::NObserver<TSPConnectionHandler, ErrorNotification>(*this, &TSPConnectionHandler::onSocketError)); _reactor.addEventHandler(_socket, Poco::NObserver<TSPConnectionHandler, TimeoutNotification>(*this, &TSPConnectionHandler::onSocketTimeout)); } virtual ~TSPConnectionHandler() { _reactor.removeEventHandler(_socket, Poco::NObserver<TSPConnectionHandler, ReadableNotification>(*this, &TSPConnectionHandler::onSocketReadable)); _reactor.removeEventHandler(_socket, Poco::NObserver<TSPConnectionHandler, WritableNotification>(*this, &TSPConnectionHandler::onSocketWritable)); _reactor.removeEventHandler(_socket, Poco::NObserver<TSPConnectionHandler, ShutdownNotification>(*this, &TSPConnectionHandler::onSocketShutdown)); _reactor.removeEventHandler(_socket, Poco::NObserver<TSPConnectionHandler, ErrorNotification>(*this, &TSPConnectionHandler::onSocketError)); _reactor.removeEventHandler(_socket, Poco::NObserver<TSPConnectionHandler, TimeoutNotification>(*this, &TSPConnectionHandler::onSocketTimeout)); } void onSocketReadable(const Poco::AutoPtr<ReadableNotification>& pNf) { cout << "READable !!" << endl; try { vector<char> m_buffer; m_buffer.resize(1024, '\0'); LONG32 m_buflen = _socket.receiveBytes(&m_buffer[0], 1024); if (m_buflen == 0) { cout << "Connection reset by peer normally" << endl; delete this; } _socket.sendBytes(&m_buffer[0], m_buflen); } catch(Poco::Net::NetException& e) { cout << "socket read exception: " << e.displayText() << endl; delete this; } } void onSocketWritable(const Poco::AutoPtr<WritableNotification>& pNf) { cout << "WRITEable !!" << endl; } void onSocketShutdown(const Poco::AutoPtr<ShutdownNotification>& pNf) { cout << "SHUTDOWN!!!!!!!!!!!!" << endl; delete(this); } void onSocketError(const Poco::AutoPtr<ErrorNotification>& pNf) { cout << "Error!!" << endl; } void onSocketTimeout(const Poco::AutoPtr<TimeoutNotification>& pNf) { cout << "Timeout!!" << endl; } private: StreamSocket _socket; SocketReactor& _reactor; }; It starts normally somewhere else in program using this code: Poco::Net::ServerSocket tcpsock("9495"); Poco::Net::SocketReactor reactor; Poco::Net::SocketAcceptor<TSPConnectionHandler> acceptor(tcpsock, reactor); Poco::Thread thread; thread.start(reactor); waitForTerminationRequest(); reactor.stop(); thread.join(); return Application::EXIT_OK; Also I have python client to test it: import socket client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) client_socket.connect(('localhost', 9495)) data = raw_input ( "Something:" ) client_socket.send(data) data = client_socket.recv(1024) print "RECIEVED:" , data client_socket.close() And I got list of questions that I don't understand how to resolve: * after python string "client_socket.connect(('localhost', 9495))" is done, server starts to spam "onSocketWritable", how to stop it? I understand I have to be notified if socket become writable, but why do it continue doing that while all socket's life? If that is normal situation, what for was designed WritableNotification? * if I will start python in debug mode and close it before "client_socket.close()", server gets exception and will be deleted throw "socket read exception: ". But errornotification and shutdownnotification will not be dispatched. Why? I never saw them dispatched anyhow. * If I will let "client_socket.close()" be done, on server side I will receive ReadableNotification and will leave throw "Connection reset by peer normally". But still there will be no ShutdownNotification. Why? Answer: 1. As soon as you are connecting to the server a socket will be instantiated and if you registred a writable notification you will get notified about this state. This means only add this event handler when you have to send data. The socket will send the data and when done, this handler is called again (asynchronous socket...). If you don't have to send more block's call removeEventHandler for this event. 2. The socket reactor uses the select command (Socket::select(readable, writable, except, _timeout)) The name errornotification is a little bit misleading (will get some error conditions but also out of bounds data). If a socket closes gracefully onReadable will be called with no available char's, otherwise Poco::Net::ConnectionResetException will be thrown. 3. The ShutdownNotification is sent when the SocketReactor is stopped. You should have a look in SocketRactor.cpp then everything is much clearer.
Why do I get "ImportError: Twisted requires zope.interface 3.6.0 or later." when running stratum mining proxy? Question: The entire return when running "sudo python ./mining_proxy.py" is: Traceback (most recent call last): File "./mining_proxy.py", line 67, in <module> from twisted.internet import reactor, defer File "/Library/Python/2.7/site-packages/Twisted-13.2.0-py2.7-macosx-10.8-intel.egg/twisted/__init__.py", line 53, in <module> _checkRequirements() File "/Library/Python/2.7/site-packages/Twisted-13.2.0-py2.7-macosx-10.8-intel.egg/twisted/__init__.py", line 51, in _checkRequirements raise ImportError(required + ".") ImportError: Twisted requires zope.interface 3.6.0 or later. This leads me to believe that zope.interface is not installed. So I try to install it: sudo easy_install zope.interface Searching for zope.interface Best match: zope.interface 4.1.1 Processing zope.interface-4.1.1-py2.7-macosx-10.8-intel.egg zope.interface 4.1.1 is already the active version in easy-install.pth Using /Library/Python/2.7/site-packages/zope.interface-4.1.1-py2.7-macosx-10.8-intel.egg Processing dependencies for zope.interface Finished processing dependencies for zope.interface I also find [this post](https://github.com/kpdyer/fteproxy/issues/66) which says you basically need to put an **init**.py into the folder. So I do: sudo touch /usr/local/lib/python2.7/site-packages/zope.interface-4.1.1/__init__.py I try to run mining proxy again, same error. Please help. Answer: I had the same error. After googling around I found that the touch should be in a different place: sudo touch /usr/local/lib/python2.7/site-packages/zope/__init__.py however it didn't work. I just fixed it using virtualenv steps here: pip install virtualenv virtualenvwrapper mkvirtual stratum-proxy pip install https://github.com/slush0/stratum-mining-proxy.git pip install zope2 After those step inside the virtualenv stratum-proxy was working successfully. hope it helps
Adding a text control window to a wxMessageDialog box/AboutDialogInfo in wxPython Question: I am working with python v2.7 and wxPython v3.0 on Windows 7 OS. In my app I have a about menu. Upon clicking the about menu I want to display some information about my app. I am trying to create a dialog box/AboutBox exactly as shown in the image below.(This is the about dialog of [notepad++](http://notepad-plus-plus.org/). Click on `?` in the menu bar of notepad++.) The special thing about the dialog box of notepad++ is that I need a text control window too. One can copy the info. ![enter image description here](http://i.stack.imgur.com/F67ou.jpg) I tried to do the same in wxPython, but unfortunately I failed. I tried two different hit and trial approaches. **1.** I tried to add the text control window to the ~~dialog box~~ wxMessageDialog but it doesn't shows up at all. **2.** I tried to use the [AboutBox](http://www.wxpython.org/docs/api/wx- module.html#AboutBox) in wxPython, and tried to add the text control to it but it failed because the AboutDialogInfo is not a window and the parent of the text control should be of a window type. Error: aboutPanel = wx.TextCtrl(info, -1, style = wx.TE_MULTILINE|wx.TE_READONLY|wx.HSCROLL) File "C:\Python27\lib\site-packages\wx-3.0-msw\wx\_controls.py", line 2019, in __init__ _controls_.TextCtrl_swiginit(self,_controls_.new_TextCtrl(*args, **kwargs)) TypeError: in method 'new_TextCtrl', expected argument 1 of type 'wxWindow *' It would be great if someone could provide some idea on how to add a text control windows to a dialog box/AboutBox? **Code:** Here is my code sample for playing around: import wx from wx.lib.wordwrap import wordwrap class gui(wx.Frame): def __init__(self, parent, id, title): wx.Frame.__init__(self,None, id, title, style=wx.DEFAULT_FRAME_STYLE) panel1 = wx.Panel(self, -1) panel1.SetBackgroundColour('#fffaaa') menuBar = wx.MenuBar() file = wx.Menu() file.Append(101, '&About1', 'About1') file.Append(102, '&About2', 'About2') menuBar.Append(file, '&File') self.SetMenuBar(menuBar) wx.EVT_MENU(self, 101, self.onAbout)# Event for the About1 menu wx.EVT_MENU(self, 102, self.onAboutDlg)# Event for the About2 menu def onAbout(self, event): message = 'This fantastic app was developed using wxPython.\nwxPython is c00l :)' dlg = wx.MessageDialog(self, message, 'My APP', wx.OK|wx.ICON_INFORMATION) aboutPanel = wx.TextCtrl(dlg, -1, style = wx.TE_MULTILINE|wx.TE_READONLY|wx.HSCROLL) aboutPanel.WriteText('Experimentation is the part of our life.\n') dlg.ShowModal() dlg.Destroy() def onAboutDlg(self, event): self.panel = wx.Panel(self, -1) info = wx.AboutDialogInfo() info.Name = "My About Box" info.Version = "0.1" info.Copyright = "(C) 2014 xxx" info.Description = wordwrap( "This is an example application that shows the problem " "that I am facing :)", 350, wx.ClientDC(self.panel)) info.WebSite = ("http://stackoverflow.com/users/2382792/pss", "My Home Page") info.Developers = ["PSS"] info.License = wordwrap("Driving license and a AK-47 too :P ", 500,wx.ClientDC(self.panel)) # Uncomment the following line to get the error! #aboutPanel = wx.TextCtrl(info, -1, style = wx.TE_MULTILINE|wx.TE_READONLY|wx.HSCROLL) #aboutPanel.WriteText('Experimentation is the part of our life.\n') wx.AboutBox(info) if __name__ == '__main__': app = wx.App() frame = gui(parent=None, id=-1, title="My-App") frame.Show() app.MainLoop() Thank you for your time! Answer: `wxAboutBox()` uses the standard about dialog for the current platform so it won't help you to achieve your goal. Similarly, `wxMessageDialog` is the native message box dialog which, again, can't have your custom text box. OTOH there is absolutely no problem with building any dialog you want using `wxDialog` and adding elements to it (and using sizers to lay them out). IOW your mistake is to think that the class you need to use is `wxMessageDialog`: it isn't, you need `wxDialog`.
Python CSV file reader : bad cells format for high numbers Question: I'm using the csv file reader of python to read a csv file. My code is the following : with open(self.csv_file, 'rb') as csvfile: data = list(csv.reader(csvfile, delimiter=';')) Everything works fine except for one column of my csv file. I have columns with float numbers that are between 1 and -1 (ex : 0,34430203959) and it works perfectly but one of my column is dealing with very high numbers (ex : 142266963436).Because the cells of the file are formatted as "standards", my CSV file is printig the number 142266963436 as 142.266.963.436 (as shown in the figure below) : ![enter image description here](http://i.stack.imgur.com/53uha.jpg) There is the problem. When I parse my CSV file, he has no problems dealing with little numbers because there is only one "." but when I parse high numbers with a lot of "." python interpret them as "float" and put the "." after the fist number. So, instead of having the number : 142266963436 I have the number : 1.42266963436 Anyone has an idea of how i could fix this ? Thanks for your help ! Answer: Your CSV file contains that oddity; it looks as if all your `z` columns are afflicted (`ankle_pos.z` and `toe_pos.z` in your screenshot). If you are certain these values are meant to be floats then you can use Python to 'repair' these: import csv def repaired_float(c): try: return float(c) except ValueError: # interpret ddd.ddd.ddd.ddd as 0.ddddddddd instead return float('.{}'.format(c.replace('.', '')) with open(filename, 'rb') as infh: reader = csv.reader(infh) next(reader, None) # skip header row for row in reader: row = map(repaired_float, row) # do something with row If you wanted to interpret those values as (large) integers, replace the last 2 lines in `repaired_float()` with: # interpret ddd.ddd.ddd.ddd as ddddddddd instead return int(c.replace('.', ''))
Split Integer List in Python Question: I have a list of integers. I want to split the main list into multiple sub lists of non-zero integers. Example: main_lists = [0,0,0,0,0,0,123,432,5,54,0,654,645,34,23,12,0,0,0,0,0,0,123,1,312,312,132,3,123,0,0,0,0,0,0,0] output = [123,432,5,54,0,654,645,34,23,12] [123,1,312,312,132,3,123] Condition is, If one or two (less than < 5) zero is found in between two non zero values, then it should include those zeros int out put lists. If more that 5 consecutive zero is found then it should split the list from that position. main_lists = [0,0,0,0,0,0,123,432,5,54,0,654,645,34,23,12,0,0,0,0,0,0,123,1,312,312,132,3,123,0,0,0,0,0,0,0] zero_count = 0 non_zero_temp = [] for i in main_lists: if i == 0: zero_count = zero_count + 1 else: if zero_count < 5: non_zero_temp.append(i) zero_count = 0 Thanks in Advance, Answer: from itertools import groupby main_lists = [ 0,0,0,0,0,0,123,432,5,54,0,654,645,34,23,12,0, 0,0,0,0,0,123,1,312,312,132,3,123,0,0,0,0,0,0,0 ] # group numbers into contiguous lists (by 0 or not-0) is_zero = lambda n: not n groups = (list(nums) for zero,nums in groupby(main_lists, key=is_zero)) # group lists into contiguous chunks (by to-keep or to-discard) is_keeper = lambda lst: bool(lst[0]) or len(lst) < 5 chunks = (chunk for keep,chunk in groupby(grouped, key=is_keeper) if keep) # reassemble chunks final = [[i for lst in chunk for i in lst] for chunk in chunks] results in [[123, 432, 5, 54, 0, 654, 645, 34, 23, 12], [123, 1, 312, 312, 132, 3, 123]]
BeautifulSoup Specify table column by number? Question: Using Python 2.7 and BeautifulSoup 4, I'm scraping song names from a table. Right now the script finds links in the row of a table; how can I specify I want the first column? Ideally I'd be able to switch numbers around to change which ones got selected. Right now the code looks like this: from bs4 import BeautifulSoup import requests r = requests.get("http://evamsharma.finosus.com/beatles/index.html") data = r.text soup = BeautifulSoup(data) for table in soup.find_all('table'): for row in soup.find_all('tr'): for link in soup.find_all('a'): print(link.contents) How do I, in effect, index the `<td>` tags within each `<tr>` tag? The URL in there right now is a page on my site where I basically copied the table source from Wikipedia to make the scraping a little simpler. Thanks! evamvid Answer: Find all `td` tags inside `tr` and get the one you need by index: index = 2 for table in soup.find_all('table'): for row in soup.find_all('tr'): try: td = row.find_all('td')[index] except IndexError: continue for link in td.find_all('a'): print(link.contents)
How can I efficiently create a user graph based on transaction data using Python? Question: I'm attempting to create a graph of users in Python using the networkx package. My raw data is individual payment transactions, where the payment data includes a user, a payment instrument, an IP address, etc. My nodes are users, and I am creating edges if any two users have shared an IP address. From that transaction data, I've created a Pandas dataframe of unique [user, IP] pairs. To create edges, I need to find [user_a, user_b] pairs where both users share an IP. Let's call this DataFrame 'df' with columns 'user' and 'ip'. I keep running into memory problems, and have tried a few different solutions outlined before. For reference, the raw transaction list was ~500,000, includes ~130,000 users, ~30,000 IPs, and likely ~30,000,000 links. 1. Join df to itself, sort pairs and remove duplicates (so that [X, Y] and [Y, X] don't both show up as unique pairs). df_pairs = df.join(df, how='inner', lsuffix='l', rsuffix='r') df_sorted_pairs = [np.sort([df_pairs['userl'][i], df_pairs['userr'][i]]) for i in range(len(df_pairs))] edges = np.asarray(pd.DataFrame(df_sorted_pairs).drop_duplicates()) This works pretty well, but gives me a Memory Error fairly quickly, as joining a table to itself grows very quickly. 2. Create a matrix, where users are the rows, IPs are the columns, and matrix elements are 1 if that user transacted on the IP and 0 otherwise. Then X.dot(X.transpose()) is a square matrix whose elements (i,j) represent how many IPs were shared by user i and user j. user_list = df['user'].unique() ip_list = df['ip'].unique() df_x = pd.DataFrame(index=user_list, columns=ip_list) df_x.fillna(0, inplace=True) for row in range(len(df)): df_x[df['ip'][row]][df['user'][row]] = 1 df_links = df_x.dot(df_x.transpose()) This works extremely well unless len(ip_list) > 5000. Just creating the empty dataframe of say, 500,000 rows x 200,000 columns gives a Memory Error. 3. Brute force. Iterate across the users one by one. For each user, find the distinct IPs. For each IP, find the distinct users. Those resulting users are therefore linked to the user in the current iteration. Add that [User1, User2] list to master list of links. user_list = df['user'].unique() ip_list = df['ip'].unique() links=[] for user in user_list: related_ip_list = df[df['user'] == user]['ip'].unique() for ip in related_ip_list: related_user_list = df[df['ip'] == ip]['user'].unique() for related_user in related_user_list: if related_user != user: links.append([user, related_user]) This works, but extremely slow. It ran for 3 hours and finally gave me a Memory Error. Because links was being saved along the way, I could check how big it got - about 23,000,000 links. Any advice would be appreciated. Have I simply gone too far into "Big Data" where traditional methods like the above aren't going to cut it? I didn't think having 500,000 transactions qualified as "Big Data" but I guess storing a 130,000 x 30,000 matrix or creating a list with 30,000,000 elements is pretty large? Answer: I think your problem is that a matrix representation is not going to cut it: Note that memory wise, you do very inefficient stuff. For example, you create a matrix with a lot of zeros that need to be allocated in RAM. It would be a lot more efficient to not have any object in RAM for a connection that does not exist instead of a zero float. You "abuse" linear algebra math to solve your problem, which makes you use a lot of RAM. (The amount of elements is in your matrix is 130k*30k = a gazilion, but you "only" have 30m links that you actually care about) I truly feel for you, because pandas was the first library I learned and I was trying to solve almost every problem with pandas. I noticed over time though that the matrix approach is not optimal for a lot of problems. There is a "spare matrix" somewhere in numpy, but let's not go there. let me suggest another approach: use a simple default dict: from collections import defaultdict # a dict that makes an empty set if you add a key that doesnt exist shared_ips = defaultdict(set) # for each ip, you generate a set of users for k, row in unique_user_ip_pairs.iterrows(): shared_ips[row['ip']].add(row['user']) #filter the the dict for ips that have more than 1 user shared_ips = {k, v for k, v in shared_ips.items() if len(v) > 1} I'm not sure if this is 100% going to solve your usercase, but note the efficiency: This will at most duplicate the RAM usage from your initial unique user-ip pairs object. But you will get the information which ip was shared amongst which users. # The big lesson is this: _If most cells in a matrix represent the same type of information, don't use a matrix approach if you run into memory problems_ I've seen so many pandas solutions for problems that could have been done with the simple usage of pythons builtin types like _dict_ , _set_ , _frozenset_ and _Counters_. Especially people coming to Python from statistical toolboxes like MATLAB and R or Excel are very very prone to it (they sure like them tables). I suggest that one tries to not make pandas his personal builtin library where he resorts to first...
Is there some equivalent function in python for pack from php? Question: I'm not familiar with binary operations in general, so for PHP i did it by examples, but can't find anything for python... I need something in python like in php `pack('H*'` and `pack('a*'`. Answer: The python [`struct`](https://docs.python.org/2/library/struct.html%29) module is what you're looking for. >>> import struct >>> struct.pack("<H", 5) # Little endian short, 2 bytes. '\x05\x00' Do note that [`php.pack()`](http://www.php.net/manual/en/function.pack.php) `H` is not the same as struct `H`. If you want to convert an integer to a hexadecimal: >>> import random >>> hex(random.randint(0, 100)) '0x4c' but in python hexadecimals are strings, so I'm not sure if that's what you're asking. If you want to actually _pack_ the output of `random.randint()` as binary data, pack the value as some integer. You can use the format characters `B, H, I, L, Q` at least.
Multiplying array in python Question: From [this](http://stackoverflow.com/questions/8194959/in-python-how-will-you- multiply-individual-elements-of-an-array-with-a-floating) question I see how to multiply a whole numpy array with the same number (second answer, by JoshAdel). But when I change P into the maximum of a (long) array, is it better to store the maximum on beforehand, or does it calculate the maximum of H just once in the second example? import numpy as np H = [12,12,5,32,6,0.5] P=H.max() S=[22, 33, 45.6, 21.6, 51.8] SP = P*np.array(S) or import numpy as np H = [12,12,5,32,6,0.5] S=[22, 33, 45.6, 21.6, 51.8] SP = H.max()*np.array(S) So does it calculate `H.max()` for every item it has to multiply, or is it smart enough to it just once? In my code `S` and `H` are longer arrays then in the example. Answer: There is little difference between the 2 methods: In [74]: import numpy as np H = np.random.random(100000) %timeit P=H.max() S=np.random.random(100000) %timeit SP = P*np.array(S) %timeit SP = H.max()*np.array(S) 10000 loops, best of 3: 51.2 µs per loop 10000 loops, best of 3: 165 µs per loop 1000 loops, best of 3: 217 µs per loop Here you can see that the individual step of pre-calculating `H.max()` is no different from calculating it in a single line
How to use a Matplotlib proxy artist with stackplot? Question: Example (runs in `ipython --pylab`): x = arange(25) Y = maximum(0,2+randn(7,25)) stackplot(x,Y) legend(('A','B','C','D','E','F','G')) **The problem:** instead of a proper legend, I get an empty rectangle. This is a [known issue](https://github.com/matplotlib/matplotlib/issues/1943) and one work-around is using another plot element that supports legend, also called a _[proxy artist](http://matplotlib.org/users/legend_guide.html#using-proxy- artist)_. Now I wonder how this idiom is translated to my case with seven data series. Here is what I tried: proxy = [Rectangle((0,0), 0,0) for _ in Y] legend(proxy, ('A','B','C','D','E','F','G')) Now I have a legend with 7 elements, but they are all blue. How can I have the proxy artists match the stackplot colors? Answer: You can read the color from the `PolyCollections` which form the stackplot. import numpy as np import matplotlib.pyplot as plt import matplotlib as mpl x = np.arange(25) Y = np.maximum(0,2+np.random.randn(7,25)) fig, ax = plt.subplots() sp = ax.stackplot(x,Y) proxy = [mpl.patches.Rectangle((0,0), 0,0, facecolor=pol.get_facecolor()[0]) for pol in sp] ax.legend(proxy, ('A','B','C','D','E','F','G')) ![enter image description here](http://i.stack.imgur.com/FxD0B.png)
Save utf-8 strings into sqlite table with python (sqlite3 module) Question: I am using python 2.7.6 and sqlite3. Here the part of code which must create the table named goods: c.execute("""create table goods( Art varchar(12) primary key, Name_G varchar(30), Meas varchar(3), Price_G double unsigned, check (Meas in ('кг.','л.','шт.')))""") Don't blame me for such method, it's the exercise requirement. THe field Meas can contain only one of three strings. They are listed in constraint and they are in Russian. This query executes succesfully but if I check the data in database I see it stores the following SQL: CREATE TABLE goods( Art varchar(12) primary key, Name_G varchar(30), Meas varchar(3), Price_G double unsigned, check (Meas in ('кг.','л.','шт.'))) As you can see, it's not Russian. Is there any method to store correct data in the database? encode() method, u'' didn't work for me. Answer: The following instructions work correctly for me: alex@rhyme ~/tmp $ echo $LANG ru_RU.UTF-8 alex@rhyme ~/tmp $ python Python 2.7.6 (default, Feb 5 2014, 11:50:47) [GCC 4.7.2 20121109 (ALT Linux 4.7.2-alt8)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import sqlite3 >>> db = sqlite3.connect('sample1.db') >>> c = db.cursor() >>> c1 = c.execute('PRAGMA encoding="UTF-8";') >>> c1 = c.execute('CREATE TABLE sample (id INTEGER PRIMARY KEY AUTOINCREMENT, t VARCHAR(3) NOT NULL DEFAULT "руб");') >>> c1 = c.execute('INSERT INTO sample DEFAULT VALUES;') >>> db.commit()
Analyse frequency of mp3 files with python Question: I am trying to write a Python script to read an MP3 file and perform some analysis on the frequencies in it. In particular, I want a spectrogram (frequency vs time) as output. However, when I read the file using open() and piped the contents to a file, I got something like this: 3763 1e65 0311 1814 b094 d3e3 25b3 641b 15a1 f146 62d6 ade6 7708 c5ec 1a0d 7395 201c 46e6 65a9 5276 688a 47eb 80e8 617e 4d66 2d82 2677 f74e e664 6220 69fa 1b46 On further research, I figured that these were somehow related to the MP3 headers and data discussed in this wiki: <http://en.wikipedia.org/wiki/MP3#File_structure> How can I use this information to extract frequency data of the file? PS: I specifically want to analyse MP3 files, NOT WAV files. A workaround would be to convert the MP3 to WAV format and then work on that, as there is a Python module to handle WAV files. But is there a solution to this problem without this conversion? Thanks in advance. Answer: If you went with .wav files, there is a python standard library that can handle them (<https://docs.python.org/2/library/wave.html>). I have played with this in the past and found it quite easy to use. For mp3 the mutagen package is an option <https://code.google.com/p/mutagen/> Also, this SO question my help: [Importing sound files into Python as NumPy arrays (alternatives to audiolab)](http://stackoverflow.com/questions/2356779/importing-sound-files- into-python-as-numpy-arrays-alternatives-to-audiolab)
Flask - Setting root directory Question: I have a folder structure that looks like so: myproject/ - flask_app/ - app.py - templates/ - module1.py - module2/ - db.py - models/ I'm running into ImportErrors in my Flask application when trying to do the following: from module2 import db # or something else like import module1 from flask import Flask app = Flask(__name__) if __name__ == "__main__": app.run(debug=True) This is obviously because the Flask app is running from its own subdirectory "flask_app". I normally would try and get around this by running it like so: python -m flask_app.app But this doesn't seem to solve the problem. Is there a way I run my flask app from the root folder without resorting to relative imports (using older version of Python) Answer: When you run `python -m flask_app.app`, most likely `sys.path` won't include the `myproject` path. Easiest would be to put a top-level script in the `myproject` directory; lets call it `runsite.py`: from flask_app.app import app app.run(debug=True) and run that with Python: $ python runsite.py
Crossplatform sound with Python standard library Question: I have searched plenty to find an answer, I have seen winsound repeatedly but that is just for windows and other modules seem to all be outside of the standard library. Is there a simple way to play a `.wav` or any sound file using something from the standard library that will work on most platforms? Answer: You can find all the information here: <https://wiki.python.org/moin/Audio/> You can see that there are some built in modules like `wave` and others which are probably way better and are also platform independent. If you choose to go with external libraries, you can plenty options like `PyMedia`, `PySDL`, `wxPython` and many others. For example, using `PyMedia`: import pymedia.audio.sound as sound f = wave.open('myFile.wav', 'rb') snd = sound.Output( f.getframerate(), f.getnchannels(), sound.AFMT_S16_LE ) s = f.readframes( 300000 ) snd.play(s)
Python openCV: I get an unchanged image when I use cvtColor Question: I have an image as a numpy array with the shape (480,640) in grayscale. I want to lay a colored mask over the image and need to get the image in the same shape to do it, which is (480,640,3). Here is what I tried: print str(img.shape) +' '+ str(type(img)) +' '+ str(img.dtype) # prints: (480, 640) <type 'numpy.ndarray'> uint8 cv2.cvtColor(img, cv2.COLOR_GRAY2BGR, img, 3) # this line seems to have no effect although I set it to 3 channels print str(img.shape) +' '+ str(type(img)) +' '+ str(img.dtype) # prints: (480, 640) <type 'numpy.ndarray'> uint8 rowCounter = 0 while rowCounter < img.shape[0]: columnCounter = 0 while columnCounter < img.shape[1]: if img[rowCounter, columnCounter] == 0: img[rowCounter, columnCounter] = [0, 0, 0] else: img[rowCounter, columnCounter] = [255, 255, 255] columnCounter += 1 rowCounter += 1 Ok, the code stops on the line where I want to assign the three values ([0, 0, 0]) instead of the single value (0). The error message reads as follows: ValueError: setting an array element with a sequence. How can I change from single value to three values? Is there a function I am not finding? Thank you! Answer: The main thing is that you need to assign the converted image to a new name. I'm not sure if using the c++ format of providing the target image as an argument works. I would just do it the usual python (cv2) way of assigning to a name (same name is fine). Also, you don't need to assign the number of channels. The conversion type takes care of that. # cv2.cvtColor(img, cv2.COLOR_GRAY2BGR, img, 3) color_mask = cv2.cvtColor(img, cv2.COLOR_GRAY2BGR) Does that get you the image you want? By the way, as long as you are using numpy/opencv you probably want to look into ways of making it more efficient. If you do individual pixel access across a whole image/numpy array, that's a red flag (for opencv in python). Below is code that shows the conversion but then ignores that and shows (as I understand it) how to apply a more efficient mask. # Copy-Paste Working (and More Efficient) Example import cv2 import numpy as np # setup an original image (this will work for anyone without needing to load one) shape = (480, 640) img_gray = np.ndarray(shape, dtype=np.uint8) img_gray.fill(127) img_gray[0:40, 100:140] = 0 # some "off" values cv2.imshow('original grayscale image', img_gray) cv2.waitKey(0) # press any key to continue # convert the gray image to color (not used. just to demonstrate) img_color = cv2.cvtColor(img_gray, cv2.COLOR_GRAY2BGR) cv2.imshow('color converted grayscale image (not used. just to show how to use cvtColor)', img_color) cv2.waitKey(0) # press any key to continue # a simplified version of what your code did to apply a mask # make a white image. # and then set it to black wherever the original grayscale image is 0 img_color = np.ndarray(img_gray.shape + (3,), dtype=np.uint8) img_color.fill(255) cv2.imshow('base color image', img_color) cv2.waitKey(0) # press any key to continue # this is not the fastest way, but I think it's more logical until you need more speed # the fastest way specifically to black out parts of the image would # be np.bitwise_and(...) black_points = np.where(img_gray == 0) print('found {} points to mask'.format(len(black_points[0]))) img_color[black_points] = (0, 0, 0) # a more efficient and still straightforward method you could use: img_color[img_gray==0] = (0, 0, 0) cv2.imshow('masked color image', img_color) cv2.waitKey(0) # press any key to continue # clean up explicitly cv2.destroyAllWindows()
PyGame: draw.rect() has invalid parameters Question: I'm trying to learn mouse events with PyGame, and I'm trying to draw a box wherever the user clicks. I'm setting a variable equal to pygame.mouse.get_pos(), and calling individual tuple members according to the mouse's x, y position. Here's the code: import pygame, sys pygame.init() screen = pygame.display.set_mode((800, 600)) mousepos = pygame.mouse.get_pos() while True: for event in pygame.event.get(): if event.type == pygame.QUIT: sys.exit() if event.type == pygame.MOUSEBUTTONDOWN: pygame.draw.rect(mousepos[0], mousepos[1], 20, 20) The game starts up, but when I click, it crashes, giving this error: Traceback (most recent call last): File "C:\Users\User\Documents\proj\Python\mouse.py", line 13, in <module> pygame.draw.rect(mousepos[0], mousepos[1], 20, 20) TypeError: must be pygame.Surface, not int I know what I'm doing wrong: my parameters for `draw.rect()` are of invalid types, but I don't know how to change the parameters so they're appropriate. So how do I fix this? Answer: Lets take a look at the function definition: pygame.draw.rect(Surface, Color, Rect, Thickness) * Surface is a surface where you want to draw * Color is a tupple with RGB values defining the color to be used * Rect is a tupple in the format: (x,y,width,height) * x,y are the coordinates of the upper left hand corner * width, height are the width and height of the rectangle * Thickness is the thickness of the line. If it is zero, the rectangle is filled. Based on this, you shoud do something like: redColor = (255,0,0) pygame.draw.rect(screen, redColor, (mousepos[0], mousepos[1], 20, 20), 1) ## Sources: The official documentation for `python.draw` can be found here: <http://www.pygame.org/docs/ref/draw.html> Mind the usefull `Search examples for <function>` button under every function description, which can lead you to multiple real world examples of usage. Useful tutorials can also be found on the official pages: <http://www.pygame.org/wiki/tutorials> Other unofficial tutorials, like [this one](http://inventwithpython.com/pygame/chapter2.html), can be found with a bit of Googling effort.
How to find URL containing one word AND another using re in Python? Question: Say I have two types of links in a html file. I want to filter out all links with type 1. How would I do it in Python using the `re` module? Type 1: http://www.domain.com/firstlevel/02-02-13/secondlevel-slug.html Type 2: http://www.domain.com/levelone/02-02-13/secondlevel-slug.html I want to find all links that contain both `firstlevel` AND `secondlevel`. This is how I tried it: import re text = "here goes the code with various links of type 1 and type 2…" findURL = re.findall('.*firstlevel.*secondlevel.*',text) Here is what I thought the regex means: find all strings that has ONE OR MORE occurances of ANY CHARACTER followed by the word firstlevel followed by ONE OR MORE occurances of ANY CHARACTER followed by the word secondlevel followed by ONE OR MORE occurances of ANY CHARACTER However I get an empty list as result. What do I do wrong? Answer: You must determine start and end of link. I.e. findURL = re.findall('http:.*firstlevel.*secondlevel.*\.html', text)
Why will my unit tests only run on a my apps, not my entire project? Question: I've just started writing my first unit tests for a django project, but have come across an issue when attempting to run all the projects tests. If I run the tests for a specific module/app it works fine: ./manage.py test my_project.api --settings=my_project.settings.test But when I attempt to run all tests in the project: ./manage.py test my_project --settings=my_project.settings.test I get an error for every tests.py that's found: ====================================================================== ERROR: my_project.api.tests.tests (unittest.loader.ModuleImportFailure) ---------------------------------------------------------------------- ImportError: Failed to import test module: my_project.api.tests.tests Traceback (most recent call last): File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/unittest/loader.py", line 252, in _find_tests module = self._get_module_from_name(name) File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/unittest/loader.py", line 230, in _get_module_from_name __import__(name) ImportError: No module named my_project.api.tests.tests I am using virtualenvwrapper with the following, python 2.7.1 django 1.6.1 Anyone know why this might be happening? **EDIT** This is an abbreviated view of my project structure: my_project_root | | |--- my_project | | | |--- api | | | | | ---- tests | | | | | --- tests.py | |--- core | | | | | ---- tests | | | | | --- tests.py | --- settings | | | ---- test.py | | --- manage.py Reading the django docs, "Test discovery is based on the unittest module's built-in test discovery. By default, this will discover tests in any file named “test*.py” under the current working directory." Which is /my_project_root/ Answer: This problem was (partially) solved within the comments, it was a combination of an environment configuration error and how test discovery works. Put simply, `__init__.py` should not be present within `my_project_root`. To make heroku be able to discover `wsgi.py`, the `$PYTHONPATH` environment variable should be adjusted to include `my_project_root`. Additionally, you can specify heroku config:set WSGI_PATH=path/to/my/file/wsgi.py
wxPython thread that does not block the GUI? Question: I am new to wxPython and threading. I am trying to move some code into a thread so that it no longer blocks my GUI while executing, and I can push another button to kill the thread. Having done this, however, the code still blocks my GUI. How can I write this code so that my thread does not block the GUI? import wx, sys import threading import time class mywxframe(wx.Frame): global sizer2, WorkerThread def __init__(self): wx.Frame.__init__(self, None) pnl = wx.Panel(self) szr = wx.BoxSizer(wx.VERTICAL) pnl.SetSizer(szr) szr2 = sizer2(self, pnl) szr.Add(szr2, 1, wx.ALL | wx.EXPAND, 10) log = wx.TextCtrl(pnl, -1,style=wx.TE_MULTILINE, size=(300,-1)) szr.Add(log, 1, wx.ALL, 10) btn3 = wx.Button(pnl, -1, "Stop") btn3.Bind(wx.EVT_BUTTON, self.OnStop) szr.Add(btn3, 0, wx.ALL, 10) redir = RedirectText(log) sys.stdout=redir szr.Fit(self) self.Show() def sizer2(self, panel): sizer = wx.BoxSizer(wx.HORIZONTAL) btn2 = wx.Button(panel, -1, "OK",) self.Bind(wx.EVT_BUTTON, self.OnStart, btn2) sizer.Add(btn2, 0, wx.ALL, 10) return sizer def WorkerThread(self): self.dead = False while (not self.dead): for i in range(0,10): print "printing", i time.sleep(3) def OnStart(self, event): our_thread = threading.Thread(target=WorkerThread(self)) our_thread.start() def OnStop(self, event): self.dead = True class RedirectText(object): def __init__(self, aWxTextCtrl): self.out=aWxTextCtrl def write(self, string): self.out.WriteText(string) app = wx.PySimpleApp() frm = mywxframe() app.MainLoop() Answer: You've got a couple problems there. First of all, if you're going to define `sizer2` and `WorkerThread` as methods, you should use them as methods, not globals. Next, when you were creating the thread you were calling `WorkerThread` and passing its return value (None) to the thread. This is where you were blocking the GUI. def OnStart(self, event): our_thread = threading.Thread(target=WorkerThread(self)) our_thread.start() Instead you should be passing a callable object (`WorkerThread` without the `()`) to the thread so it will then be able to call it in the context of the new thread. Finally, since `self.out.WriteText` manipulates a UI object it must be called in the context of the GUI thread. Using `wx.CallAfter` is an easy way to do that. Here is your example updated with these changes: import wx, sys import threading import time print wx.version() class mywxframe(wx.Frame): def __init__(self): wx.Frame.__init__(self, None) pnl = wx.Panel(self) szr = wx.BoxSizer(wx.VERTICAL) pnl.SetSizer(szr) szr2 = self.sizer2(pnl) szr.Add(szr2, 1, wx.ALL | wx.EXPAND, 10) log = wx.TextCtrl(pnl, -1,style=wx.TE_MULTILINE, size=(300,-1)) szr.Add(log, 1, wx.ALL, 10) btn3 = wx.Button(pnl, -1, "Stop") btn3.Bind(wx.EVT_BUTTON, self.OnStop) szr.Add(btn3, 0, wx.ALL, 10) redir = RedirectText(log) sys.stdout=redir szr.Fit(self) self.Show() def sizer2(self, panel): sizer = wx.BoxSizer(wx.HORIZONTAL) btn2 = wx.Button(panel, -1, "OK",) self.Bind(wx.EVT_BUTTON, self.OnStart, btn2) sizer.Add(btn2, 0, wx.ALL, 10) return sizer def WorkerThread(self): self.dead = False while (not self.dead): for i in range(0,10): print "printing", i if self.dead: break time.sleep(3) print 'thread exiting' def OnStart(self, event): our_thread = threading.Thread(target=self.WorkerThread) our_thread.start() def OnStop(self, event): self.dead = True class RedirectText(object): def __init__(self, aWxTextCtrl): self.out=aWxTextCtrl def write(self, string): wx.CallAfter(self.out.WriteText, string) app = wx.App() frm = mywxframe() app.MainLoop()
Push rejected, failed to compile Python app Question: I'm getting a rejected error when trying to deploy a Django app to Heroku. I looked at possible solutions here: 1. [Heroku push rejected, failed to compile Python/django app (Python 2.7)](http://stackoverflow.com/questions/13896736/heroku-push-rejected-failed-to-compile-python-django-app-python-2-7) 2. [Error pushing Django project to Heroku](http://stackoverflow.com/questions/14492538/error-pushing-django-project-to-heroku) But neither worked for me. This is my flow from initiating the push to heroku: git push heroku master Initializing repository, done. Counting objects: 7024, done. Delta compression using up to 4 threads. Compressing objects: 100% (5915/5915), done. Writing objects: 100% (7024/7024), 8.77 MiB | 104 KiB/s, done. Total 7024 (delta 2183), reused 0 (delta 0) -----> Python app detected -----> No runtime.txt provided; assuming python-2.7.6. -----> Preparing Python runtime (python-2.7.6) -----> Installing Setuptools (2.1) -----> Installing Pip (1.5.4) -----> Installing dependencies using Pip (1.5.4) Downloading/unpacking Django==1.6.2 (from -r requirements.txt (line 1)) Downloading/unpacking argparse==1.2.1 (from -r requirements.txt (line 2)) argparse an externally hosted file and may be unreliable Running setup.py (path:/tmp/pip_build_u16439/argparse/setup.py) egg_info for package argparse no previously-included directories found matching 'doc/_build' no previously-included directories found matching 'env24' no previously-included directories found matching 'env25' no previously-included directories found matching 'env26' no previously-included directories found matching 'env27' Downloading/unpacking distribute==0.6.24 (from -r requirements.txt (line 3)) Running setup.py (path:/tmp/pip_build_u16439/distribute/setup.py) egg_info for package distribute warning: no files found matching 'Makefile' under directory 'docs' warning: no files found matching 'indexsidebar.html' under directory 'docs' Downloading/unpacking dj-database-url==0.3.0 (from -r requirements.txt (line 4)) Downloading dj_database_url-0.3.0-py2.py3-none-any.whl Downloading/unpacking dj-static==0.0.5 (from -r requirements.txt (line 5)) Downloading dj-static-0.0.5.tar.gz Running setup.py (path:/tmp/pip_build_u16439/dj-static/setup.py) egg_info for package dj-static Downloading/unpacking django-toolbelt==0.0.1 (from -r requirements.txt (line 6)) Downloading django-toolbelt-0.0.1.tar.gz Running setup.py (path:/tmp/pip_build_u16439/django-toolbelt/setup.py) egg_info for package django-toolbelt Downloading/unpacking gunicorn==18.0 (from -r requirements.txt (line 7)) Running setup.py (path:/tmp/pip_build_u16439/gunicorn/setup.py) egg_info for package gunicorn Downloading/unpacking psycopg2==2.5.2 (from -r requirements.txt (line 8)) Running setup.py (path:/tmp/pip_build_u16439/psycopg2/setup.py) egg_info for package psycopg2 Downloading/unpacking pystache==0.5.3 (from -r requirements.txt (line 9)) Running setup.py (path:/tmp/pip_build_u16439/pystache/setup.py) egg_info for package pystache pystache: using: version '2.1' of <module 'setuptools' from '/app/.heroku/python/lib/python2.7/site-packages/setuptools-2.1-py2.7.egg/setuptools/__init__.pyc'> Downloading/unpacking static==1.0.2 (from -r requirements.txt (line 10)) Downloading static-1.0.2.tar.gz Running setup.py (path:/tmp/pip_build_u16439/static/setup.py) egg_info for package static Installing collected packages: Django, argparse, distribute, dj-database-url, dj-static, django-toolbelt, gunicorn, psycopg2, pystache, static Running setup.py install for argparse no previously-included directories found matching 'doc/_build' no previously-included directories found matching 'env24' no previously-included directories found matching 'env25' no previously-included directories found matching 'env26' no previously-included directories found matching 'env27' Running setup.py install for distribute Before install bootstrap. Scanning installed packages Setuptools installation detected at /app/.heroku/python/lib/python2.7/site-packages/setuptools-2.1-py2.7.egg Egg installation Patching... Renaming /app/.heroku/python/lib/python2.7/site-packages/setuptools-2.1-py2.7.egg into /app/.heroku/python/lib/python2.7/site-packages/setuptools-2.1-py2.7.egg.OLD.1397160440.32 Patched done. Relaunching... Traceback (most recent call last): File "<string>", line 1, in <module> NameError: name 'install' is not defined Complete output from command /app/.heroku/python/bin/python -c "import setuptools, tokenize;__file__='/tmp/pip_build_u16439/distribute/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-7JPdSe-record/install-record.txt --single-version-externally-managed --compile: Before install bootstrap. Scanning installed packages Setuptools installation detected at /app/.heroku/python/lib/python2.7/site-packages/setuptools-2.1-py2.7.egg Egg installation Patching... Renaming /app/.heroku/python/lib/python2.7/site-packages/setuptools-2.1-py2.7.egg into /app/.heroku/python/lib/python2.7/site-packages/setuptools-2.1-py2.7.egg.OLD.1397160440.32 Patched done. Relaunching... Traceback (most recent call last): File "<string>", line 1, in <module> NameError: name 'install' is not defined ---------------------------------------- Cleaning up... Command /app/.heroku/python/bin/python -c "import setuptools, tokenize;__file__='/tmp/pip_build_u16439/distribute/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-7JPdSe-record/install-record.txt --single-version-externally-managed --compile failed with error code 1 in /tmp/pip_build_u16439/distribute Storing debug log for failure in /app/.pip/pip.log ! Push rejected, failed to compile Python app My `requirements.txt` Django==1.6.2 argparse==1.2.1 distribute==0.6.24 dj-database-url==0.3.0 dj-static==0.0.5 django-toolbelt==0.0.1 gunicorn==18.0 psycopg2==2.5.2 pystache==0.5.3 static==1.0.2 wsgiref==0.1.2 `Procfile` web: gunicorn app.wsgi I've followed the instructions from the Heroku website. Any idea what I'm missing? Answer: This is apparently a [bug in the `distribute` package](https://bitbucket.org/tarek/distribute/issue/91/install-glitch-when- using-pip-virtualenv), which doesn't seem likely to get fixed: > Distribute is now considered deprecated and replaced by setuptools. I > suggest replacing 'distribute==0.6.28' in requirements.txt with > 'setuptools==1.0' or similar. The latest versions of pip (>=1.4) and > setuptools (>=0.7) have better support for the unified code and upgrades and > seek to obviate issues like the one encountered here.
How to apply SVG Filter to Group using svgwrite with Python? Question: Does anybody have an example of how to apply SVG filter to a SVG group using svgwrite? Here's what I'm trying to do: import svgwrite dwg = svgwrite.Drawing('test.svg', profile='full') grp = dwg.g() grp.add(dwg.rect(insert=(5,5),size=(20,20))) filtr = dwg.defs.add( dwg.filter(id="Ga",filterUnits="userSpaceOnUse") ) feGauss = filtr.feGaussianBlur() grp.filter = feGauss # This does not work dwg.add(grp) dwg.save() The result does not pass filter onto the group as expected. >>> dwg.tostring() u'<svg baseProfile="full" height="100%" version="1.1" width="100%" xmlns="http://www.w3.org/2000/svg" xmlns:ev="http://www.w3.org/2001/xml-events" xmlns:xlink="http://www.w3.org/1999/xlink"><defs /><g><rect height="20" width="20" x="5" y="5" /></g></svg>' Any help is highly appreciated! Answer: Below is an example of using a simple blur filter on a group with a single rectangle. More of my svgwrite examples can be found at <https://docs.google.com/folder/d/0BwFQiTKfux0qY1Y2d1hRdndtSEk/edit> #!/usr/bin/python3 # License: MIT import svgwrite progname = 'example_filter_on_group' def create_svg(name): svg_size_w = 900 svg_size_h = 1500 title_size = 20 y = 0 title = name + ': example of filter on a group' dwg = svgwrite.Drawing(name, (svg_size_w, svg_size_h), debug=True) # background will be white. dwg.add(dwg.rect(insert=(0, 0), size=('100%', '100%'), fill='white')) # create simple filter to blur rectangle blur6_filter = dwg.defs.add(dwg.filter()) blur6_filter.feGaussianBlur(in_='SourceGraphic', stdDeviation=6) # group with filter g_f = dwg.add(dwg.g(filter=blur6_filter.get_funciri())) g_f.add( dwg.rect(insert=(50, 50), size=(50, 50), fill='aqua')) dwg.save() if __name__ == '__main__': create_svg(progname + '.svg') * Lawrence
Python code not reading file, says file has no lines Question: I had an assignment due that asked to read a file and display the top 10 lines of the file, or all of the lines if the file is less than 10 lines long. When I tried to run my code on my computer, it registered the file as having 0 lines (no matter what file I used) and displayed only a blank line as output. I would like to understand where I went wrong so I can avoid my mistake for the next assignment. Any style or other tips are also welcome. Here is my code: #Displays the top 10 lines in a file import sys # Make sure the input is correct, take file name if len(sys.argv) == 2: filename = sys.argv[1] else: print("You must start the program with 1 command line parameter.") quit() # open file fle = open(filename, "r") #Count number of lines linecount = 0 for line in fle: linecount = linecount + 1 # If the file is less than 10 lines, print the entire file # If the file has more than 10 lines, print only first 10. lines = fle.readlines() if linecount < 10: for line in fle: print(line,) else: for i in range(10): print(lines[i]) Answer: Could it be that for line in fle: linecount = linecount + 1 reads every line from the file so that, after the loop is done, there are no more lines to read from that file in `lines = fle.readlines()`? Try inserting a `fle.seek(0)` before `lines = fle.readlines()` to "rewind" the file to the beginning before re-reading it. (See also [here](http://stackoverflow.com/questions/10255273/iterating-on-a- file-using-python) for example.)
RegEx pattern returning all words except those in parenthesis Question: I have a text of the form: > können {konnte, gekonnt} Verb And I want to get a match for all words in it that are not in parenthesis. That means: > können = 1st match, Verb = 2nd match Unfortunately I still don't get the knock of regular expression. There is a lot of testing possibility but not much help for creation unless you want to read a book. I will use them in Java or Python. Answer: In Python you could do this: import re regex = re.compile(r'(?:\{.*?\})?([^{}]+)', re.UNICODE) print 'Matches: %r' % regex.findall(u'können {konnte, gekonnt} Verb') Result: Matches: [u'können ', u' Verb'] Although I would recommend simply replacing everything between `{` and `}` like so: import re regex = re.compile(r'\{.*?\}', re.UNICODE) print 'Output string: %r' % regex.sub('', u'können {konnte, gekonnt} Verb') Result: Output string: u'können Verb'
Biopython Large Sequence splitting Question: I'm a newbie in the field of python programming. As I was trying to do some analysis,(I've tried to find the answer on other posts, but nothing) I decided to post my first and probably very foolish question. Why does this create only one output file although in this example there were supposed to be at least 8 (sequence is more than 8000 characters). Thank you for your answer upfront. def batch_iterator(iterator, batch_size) : entry = True while entry : batch = [] while len(batch) < batch_size : try : entry = iterator.next() except StopIteration : entry = None if entry is None : #End of file break batch.append(entry) if batch : yield batch from Bio import SeqIO record_iter = SeqIO.parse(open("some.fasta"),"fasta") for i, batch in enumerate(batch_iterator(record_iter, 1000)) : #I think sth is wrong here? filename = "group_%i.fasta" % (i+1) handle = open(filename, "w") count = SeqIO.write(batch, handle, "fasta") handle.close() print "Wrote %i records to %s" % (count, filename) Answer: ### Sequence chunks After a long discussion with the OP, here is my very restructured proposal, using the generator function defined in [this other SO thread](http://stackoverflow.com/questions/312443/how-do-you-split-a-list- into-evenly-sized-chunks-in-python) # file: main.py from Bio import SeqIO from Bio.Seq import Seq from Bio.SeqRecord import SeqRecord def chunks(l, n): """Yield successive n-sized chunks from l.""" for i in xrange(0, len(l), n): yield l[i:i+n] if __name__ == '__main__': handle = open('long.fasta', 'r') records = list(SeqIO.parse(handle, "fasta")) record = records[0] for pos, chunk in enumerate(chunks(record.seq.tostring(), 1000)): chunk_record = SeqRecord(Seq( chunk, record.seq.alphabet), id=record.id, name=record.name, description=record.description) outfile = "group_%d.fasta" % pos SeqIO.write(chunk_record, open(outfile, 'w'), "fasta") Note that your original code does something very different: it takes **new records** from the generator provided by the `SeqIO.parse` function, and tries to store them in different files. If you want to split **a single record** in smaller sub-sequences, you have to access the record's internal data, which is done by `record.seq.tostring()`. The `chunks` generator function, as described in the other thread linked above, returns as many chunks as is possible to build from the passed in sequence. Each of them is stored as a new fasta record in a different file (if you want to keep just the sequence, write the `chunk` directly to the opened `outfile`). ### Check that it works Consider the following code: # file: generate.py from Bio.Seq import Seq from Bio.SeqRecord import SeqRecord from Bio.Alphabet import IUPAC from Bio import SeqIO long_string = "A" * 8000 outfile = open('long.fasta', 'w') record = SeqRecord(Seq( long_string, IUPAC.protein), id="YP_025292.1", name="HokC", description="toxic membrane protein, small") SeqIO.write(record, outfile, "fasta") It writes a single record to a file named "long.fasta". This single record has a Sequence inside that is 8000 characters long, as generated in `long_string`. How to use it: $ python generate.py $ wc -c long.fasta 8177 long.fasta The overhead over 8000 characters is the file header. How to split that file in chunks of 1000 length each, with the code snippet above: $ python main.py $ ls generate.py group_1.fasta group_3.fasta group_5.fasta group_7.fasta main.py group_0.fasta group_2.fasta group_4.fasta group_6.fasta long.fasta $ wc -c group_* 1060 group_0.fasta 1060 group_1.fasta 1060 group_2.fasta 1060 group_3.fasta 1060 group_4.fasta 1060 group_5.fasta 1060 group_6.fasta 1060 group_7.fasta 8480 total
Max retries exceeded with URL Question: I'm trying to get the content of this url "<https://itunes.apple.com/in/genre/ios-business/id6000?mt=8>" and its showing this error Traceback (most recent call last): File "/home/preetham/Desktop/eg.py", line 17, in <module> page1 = requests.get(ap) File "/usr/local/lib/python2.7/dist-packages/requests/api.py", line 55, in get return request('get', url, **kwargs) File "/usr/local/lib/python2.7/dist-packages/requests/api.py", line 44, in request return session.request(method=method, url=url, **kwargs) File "/usr/local/lib/python2.7/dist-packages/requests/sessions.py", line 383, in request resp = self.send(prep, **send_kwargs) File "/usr/local/lib/python2.7/dist-packages/requests/sessions.py", line 486, in send r = adapter.send(request, **kwargs) File "/usr/local/lib/python2.7/dist-packages/requests/adapters.py", line 378, in send raise ConnectionError(e) requests.exceptions.ConnectionError: HTTPSConnectionPool(host='itunes.apple.com', port=443): Max retries exceeded with url: /in/app/adobe-reader/id469337564?mt=8 (Caused by <class 'socket.gaierror'>: [Errno -2] Name or service not known) the code is url="https://itunes.apple.com/in/genre/ios-business/id6000?mt=8" page = requests.get(url) tree = html.fromstring(page.text) flist=[] plist=[] for i in range(0,100): app = tree.xpath("//div[@class='column first']/ul/li/a/@href") ap=app[0] page1 = requests.get(ap) when I try the range with (0,2) it works but when I put the range in 100's it shows this error. Answer: What happened here is that **itunes** server refuses your connection (you're sending too many requests from same ip address in short period of time) > Max retries exceeded with url: /in/app/adobe-reader/id469337564?mt=8 error trace is misleading it should be something like **"No connection could be made because the target machine actively refused it"**. There is an issue at about python.requests lib at Github, check it out [here](https://github.com/kennethreitz/requests/issues/1198) To overcome this issue (not so much an issue as it is misleading debug trace) you should catch connection related exceptions like so: try: page1 = requests.get(ap) except requests.exceptions.ConnectionError: r.status_code = "Connection refused" Another way to overcome this problem is if you use enough time gap to send requests to server this can be achieved by `sleep(timeinsec)` function in python (don't forget to import sleep) from time import sleep All in all requests is awesome python lib, hope that solves your problem.
how to read "\n\n" in python module pandas? Question: There is a data file which has `\n\n` at the end of every line. <http://pan.baidu.com/s/1o6jq5q6> My system:win7+python3.3+R-3.0.3 In R sessionInfo() [1] LC_COLLATE=Chinese (Simplified)_People's Republic of China.936 [2] LC_CTYPE=Chinese (Simplified)_People's Republic of China.936 [3] LC_MONETARY=Chinese (Simplified)_People's Republic of China.936 [4] LC_NUMERIC=C [5] LC_TIME=Chinese (Simplified)_People's Republic of China.936 In python: chcp 936 I can read it in R. read.table("test.pandas",sep=",",header=TRUE) It is so simple. and I can read it in python to get almost same output. fr=open("g:\\test.pandas","r",encoding="gbk").read() data=[x for x in fr.splitlines() if x.strip() !=""] for id,char in enumerate(data): print(str(id)+","+char) When i read it in python module pandas, import pandas as pd pd.read_csv("test.pandas",sep=",",encoding="gbk") I found two problems in the output: 1)how to make right alignment(the problem i have asked in other post) [how to set alignment in pandas in python](http://stackoverflow.com/questions/23008636/how-to-set-alignment-in- pandas-in-python) 2)there is a NaN line in every real data. Can i improve my pandas code to get better display in console? ![enter image description here](http://i.stack.imgur.com/tRQJZ.jpg) ![enter image description here](http://i.stack.imgur.com/iiMFh.jpg) ![enter image description here](http://i.stack.imgur.com/UahIb.jpg) Answer: Your file when read with `open('test.pandas', 'rb')` seems to contain '\r\r\n' as its line terminators. Python 3.3 does seem to convert this to '\n\n' while Python 2.7 converts it to '\r\n' when read with `open('test.pandas', 'r', encoding='gbk')`. [pandas.read_csv](http://pandas.pydata.org/pandas- docs/stable/generated/pandas.read_csv.html?highlight=lineterminator) does have a lineterminator parameter but it only accepts single character terminators, so that doesn't help us. What you can do is process the file a bit before passing it to `pandas.read_csv()`, and you can use [StringIO](https://docs.python.org/3.3/library/io.html?#io.StringIO) which will wrap a string buffer in a file interface so that you don't need to write out a temporary file first. import pandas as pd from io import StringIO contents = open('test.pandas', 'r', encoding='gbk') contents = contents.replace('\n\n', '\n') df = pd.read_csv(StringIO(contents)) (I don't have the GBK charset for the output below.) >>> df[0:10] ??????? ??? ???????? 0 HuangTianhui ?? 1948/05/28 1 ?????? ? 1952/03/27 2 ??? ? 1994/12/09 3 LuiChing ? 1969/08/02 4 ???? ?? 1982/03/01 5 ???? ?? 1983/08/03 6 YangJiabao ? 1988/08/25 7 ?????????????? ?? 1979/07/10 8 ?????? ? 1949/10/20 9 ???»? ? 1951/10/21 In Python 2.7 `StringIO()` was in module `StringIO` instead of `io`.
Check if string contains a certain amount of words of another string Question: Say we have a string 1 `A B C D E F` and a string 2 `B D E` (The letters are just for demo, in reality they are words). Now I would like to find out if there are any `n` conscutive "words" from string 2 in string 1. To convert the string to "words", I'd use `string.split()`. For example for `n` equals 2, I would like to check whether `B D` or `D E` is - **in this order** \- in string 1. `B D` is not in this order in the string, but `D E` is. Does anyone see a pythonic way of doing this? I do have a solution for `n` equals 2 but realized that I need it for arbitrary n. Also it is not particularily beautiful: def string_contains_words_of_string(words_str, words_to_check_str): words = words_str.split() words_to_check = words_to_check_str.split() found_word_index = None for word in words: start = 0 if found_word_index is None else found_word_index + 1 for i, word_to_check in enumerate(words_to_check[start:]): if word_to_check == word: if found_word_index is not None: return True found_word_index = i break else: found_word_index = None return False Answer: This is easy with a regex: >>> import re >>> st1='A B C D E F' >>> st2='B D E' >>> n=2 >>> pat=r'(?=({}))'.format(r's+'.join(r'\w+' for i in range(n))) >>> print [(s, s in st1) for s in re.findall(pat, st2)] [('B D', False), ('D E', True)] The key is to use a zero width look ahead to find overlapping matches in the string. So: >>> re.findall('(?=(\\w+\\s+\\w+))', 'B D E') ['B D', 'D E'] Now build that for `n` repetitions of the word found by `\w+` with: >>> n=2 >>> r'(?=({}))'.format(r's\+'.join(r'\w+' for i in range(n))) '(?=(\\w+\\s+\\w+))' Now since you have two strings, use Python's `in` operator to produce a tuple of the result of `s` from the regex matches to the target string. * * * Of course if you want a non-regex to do this, just produce substrings n words by n: >>> li=st2.split() >>> n=2 >>> [(s, s in st1) for s in (' '.join(li[i:i+n]) for i in range(len(li)-n+1))] [('B D', False), ('D E', True)] And if you want the index (either method) you can use [str.find](https://docs.python.org/2/library/stdtypes.html#str.find): >>> [(s, st1.find(s)) for s in (' '.join(li[i:i+n]) for i in range(len(li)-n+1)) ... if s in st1] [('D E', 6)] * * * For regex that goes word by word, make sure you use a word boundary anchor: >>> st='wordW wordX wordY wordZ' >>> re.findall(r'(?=(\b\w+\s\b\w+))', st) ['wordW wordX', 'wordX wordY', 'wordY wordZ']
Access to ctypes **argv from binary file through Python Question: I have the following struct output in a binary file from hashcat restore file: typedef struct { uint32_t version_bin; char cwd[256]; uint32_t argc; char **argv; uint32_t pid; uint32_t devices_cnt; uint32_t dictpos; uint32_t maskpos; uint64_t *pw_off; uint64_t *pw_num; uint64_t pw_cur; uint32_t digests_cnt; uint32_t digests_done; uint *digests_shown; uint32_t salts_cnt; uint32_t salts_done; uint *salts_shown; float ms_running; } restore_data_t; I'm trying to import the raw data and parse it with a Python script using the ctypes data structure as follows: class RestoreStruct(Structure): _fields_ = [ ("version_bin", c_uint32), ("cwd", c_char*256), ("argc", c_uint32), ("argv", POINTER(POINTER(c_char))), ("pid", c_uint32), ("devices_cnt", c_uint32), ("dictpos", c_uint32), ("maskpos", c_uint32), ("pw_off", POINTER(c_uint64)), ("pw_NUM", POINTER(c_uint64)), ("pw_CUR", c_uint64), ("digests_cnt", c_uint32), ("digests_done", c_uint32), ("digests_shown", POINTER(c_uint32)), ("salts_cnt", c_uint32), ("salts_done", c_uint32), ("salts_shown", POINTER(c_uint*30)), ("ms_running", c_float) ] with open("cudaHashcat.restore", "rb") as restore_file: status = [] struct = RestoreStruct() while restore_file.readinto(struct) == sizeof(struct): status.append((struct.version_bin, struct.cwd, struct.argc, struct.argv, \ struct.pid, struct.devices_cnt, struct.dictpos, struct.maskpos, struct.pw_off, \ struct.pw_NUM, struct.pw_CUR, struct.digests_cnt, struct.digests_done, struct.digests_shown, \ struct.salts_cnt, struct.salts_done, struct.salts_shown, struct.ms_running)) print struct._fields_[0][0], status[0][0] print struct._fields_[1][0], status[0][1] print struct._fields_[2][0], status[0][2] print struct._fields_[3][0], status[0][3] print struct._fields_[4][0], status[0][4] print struct._fields_[5][0], status[0][5] print struct._fields_[6][0], status[0][6] print struct._fields_[7][0], status[0][7] print struct._fields_[8][0], status[0][8] print struct._fields_[9][0], status[0][9] print struct._fields_[10][0], status[0][10] print struct._fields_[11][0], status[0][11] print struct._fields_[12][0], status[0][12] print struct._fields_[13][0], status[0][13] print struct._fields_[14][0], status[0][14] print struct._fields_[15][0], status[0][15] print struct._fields_[16][0], status[0][16] print struct._fields_[17][0], status[0][17] This issue I'm having is how to access the data in the pointer ctypes (argv,pw_off, etc)? I've tried the "contents", but I get "NULL pointer access" error. argv should be an array of char arrays, and the others should be a simple pointer to an int. How would I access the actual data that the pointers are addressing? Am I completely off on how I'm going about this? Here is a base64 encoded version of the restore file: > ZQAAAEU6XG9jbEhhc2hjYXQtMS4wMQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA > AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA > AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA > AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA > AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAJAAAACBdvAHwiAAABAAAAAAAAAAAAAAAA > AAAAAAAAAAAAAAABACgBAAAAAA8AAAAFAAAAAAAAAAEAAAAAAAAAAAAAAEDPnkYAAAAAY3VkYUhh > c2hjYXQzMgotbQoxMDAwCi1hCjAKLXIKcnVsZXNccmljaF9wd19ydWxlcy5ydWxlCi4uXHBsYWlu > X3RleHRfaGFzaC50eHQKLi5cMTZfV2Fsa19taW4udHh0Cv//JwEAAAAAAAAIAAAAAAAAAAAAAQAA > AAAAAAABAAAAAQAAAAAAAAAAAAAAAAAAAAEAAAAAAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA As pointed out in the comments it looks like the argv values are stored in the file as plain text. My issue is still how to read this information into a struct properly. All of the other values in the restore struct are read in and stored correctly in the python object, but the code above. Any pointer structure though doesn't read in as easy. Answer: Taking eryksun's advice here what I did to get the argv values. class RestoreStruct(Structure): _fields_ = [ ("version_bin", c_uint32), ("cwd", c_char*256), ("argc", c_uint32), ("argv", POINTER(POINTER(c_char))), ("pid", c_uint32), ("devices_cnt", c_uint32), ("dictpos", c_uint32), ("maskpos", c_uint32), ("pw_off", POINTER(c_uint64)), ("pw_NUM", POINTER(c_uint64)), ("pw_CUR", c_uint64), ("digests_cnt", c_uint32), ("digests_done", c_uint32), ("digests_shown", POINTER(c_uint32)), ("salts_cnt", c_uint32), ("salts_done", c_uint32), ("salts_shown", POINTER(c_uint*30)), ("ms_running", c_float) ] with open("cudaHashcat.restore", "rb") as restore_file: status = [] struct = RestoreStruct() restore_file.readinto(struct) rest = restore_file.read() print struct.version_bin # Print rest of variables that are not pointers print rest.splitlines()[0:struct.argc] # Prints a list structure of argv values