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Rounding logic in Python?
Question: In my original code I was trying to compute some indices out of some float
values and I faced the following problem:
>>> print int((1.40-.3)/.05)
21
But:
>>> print ((1.40-.3)/.05)
22.0
I am speechless about what is going on. Can somebody please explain?
Answer: This is caused by floating point inaccuracy:
>>> print repr((1.40-.3)/.05)
21.999999999999996
You could try using the `Decimal` type instead:
>>> from decimal import Decimal
>>> Decimal
<class 'decimal.Decimal'>
and then
>>> (Decimal('1.40') - Decimal('.3')) / Decimal('.05')
Decimal('22')
The `fractions.Fraction` class would work too. Or, you could just round:
>>> round((1.40-.3)/.05, 10) # round to 10 decimal places
22.0
|
How can I access a file in a completely different directory based on absolute path (Python)
Question:
import os
test = os.path.exists("c:/conf.txt")
if test == False:
with open("c:/conf.txt", "w") as Inc:
Inc.write("0")
Inc.close()
quit()
if test == True:
f = open("c:/conf.txt", 'r')
b = int(f.readline())
b +=1
with open("c:/conf.txt", 'w') as writeinc:
writeinc.write(str(b))
writeinc.close()
using `open(c:/conf.txt)` doesn't work (also tried c:\\.)
I get the following error message:
IOError: [Errno 22] invalid mode ('w') or filename: 'c:/conf.txt'
Is there a way to access a different directory using `open()` according to
absolute path rather than relative?
Answer: Sounds to me like you don't have permission to write to the root path of your
drive. In Windows 7 and 8, you cannot create files in the root directory:
> In Windows 7 or 8 (may be Vista), users (even administrators) are not
> allowed to create files in the C drive root directory, otherwise, an error
> message like “A required privilege is not held by the client” or “access is
> denied” will be prompted.
[Source](http://www.mkyong.com/computer-tips/cant-create-file-in-the-c-drive-
root-directory-windows-8/)
The article goes on how to modify the registry if you want to get around this
restriction.
> 1. Press keys “Windows Key + R”, type regedit
> 2. Locate
> HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA
> 3. Update the EnableLUA value to 0 (turn if off)
> 4. Restart Windows.
>
|
StatementError: SQLite Date type only accepts Python date objects as input
Question: I am using Flask-Security, the code seems fine, but when inserting a data from
register view it gives the bellow error. Since I made SECURITY_TRACKABLE =
True I added some extra fields in my models and the problem might be there :(
sqlalchemy.exc.StatementError
StatementError: SQLite Date type only accepts Python date objects as input.
(original cause: TypeError: SQLite Date type only accepts Python date objects as input.)
'INSERT INTO user (name, surname, email, password, birth_date, active, confirmed_at, last_login_at, current_login_at, last_login_ip, current_login_ip, login_count)
VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)' [{'surname': u'Example', 'name': u'Test',
'confirmed_at': None, 'login_count': None, 'last_login_ip': None, 'active': True,
'last_login_at': None, 'current_login_at': None, 'birth_date': u'1989-04-27',
'password': '$6$rounds=100000$yvVNKKdF5OFZY4Ur$bOpszUhnYVeMkY1fNwkjEcsA.BzOGCyelnPq9eKqmJFoTJ52Zd5cngYDqFQaPTZwSHoFq851IWGbl/gTqEUC1.',
'email': u'[email protected]', 'current_login_ip': None}]
here is the form that I wrote to extend my RegisterForm:
from wtforms.validators import Required
from werkzeug.security import generate_password_hash, \
check_password_hash
# to override the default RegisterForm
from flask_security.forms import RegisterForm, ConfirmRegisterForm, Form,\
TextField, BooleanField, \
PasswordField, validators
from flask.ext.security import Security, SQLAlchemyUserDatastore
class LoginForm(Form):
"""this class is used for user
access to the web application"""
username = TextField('username',
validators = [Required()])
password = PasswordField('password',
validators = [Required()])
remember_me = BooleanField('remember_me', default = False)
#unhash the password
def password_unhash(self, hashed_passw, submited_passw):
return check_password_hash(hashed_passw, submited_passw)
class ExtendedConfirmRegisterForm(ConfirmRegisterForm):
name = TextField('Name',
[validators.Length(max=255),
validators.Required()])
surname = TextField('Surname',
[validators.Length(max=255)])
birth_date = TextField('Date of birth',
[validators.Length(max=10)])
class ExtendedRegisterForm(RegisterForm):
"""RegisterForm class needed for retrieving data from user"""
#returns false if the email exists
def email_unique(self, email):
if models.User.query.\
filter_by(email = email).\
first() != None:
self.email.errors.\
append('This E-mail address is already in use. '
'Please choose another one.')
return False
else:
return True
this is my models.py:
from app import db
from flask.ext.security import UserMixin, RoleMixin
#association table that stores users and their roles
roles_users = db.Table('roles_users',
db.Column('user_id', db.Integer(), db.ForeignKey('user.id')),
db.Column('role_id', db.Integer(), db.ForeignKey('role.id')))
#orm table that stores information on roles
class Role(db.Model, RoleMixin):
id = db.Column(db.Integer(), primary_key=True)
name = db.Column(db.String(80), unique=True)
description = db.Column(db.String(255))
class User(db.Model, UserMixin):
"""a class that used to create ORM Database and
objects related to the class"""
id = db.Column(db.Integer, primary_key = True)
name = db.Column(db.String(255))
surname = db.Column(db.String(255))
email = db.Column(db.String(255), unique = True)
password = db.Column(db.String(255))
birth_date = db.Column(db.Date)
active = db.Column(db.Boolean())
roles = db.relationship('Role', secondary=roles_users,
backref=db.backref('users', lazy='dynamic'))
#SECURITY_CONFIRMABLE
confirmed_at = db.Column(db.DateTime())
#SECURITY_TRACKABLE
last_login_at = db.Column(db.DateTime())
current_login_at = db.Column(db.DateTime())
last_login_ip = db.Column(db.String(40))
current_login_ip = db.Column(db.DateTime())
login_count = db.Column(db.Integer(6))
Answer: You have a `birth_date` column but used a text field in the form. Flask-
Security uses [WTForms](http://wtforms.readthedocs.org/en/latest/) for the
form definitions; it has a dedicated [`DateField`
type](http://wtforms.readthedocs.org/en/latest/fields.html#wtforms.fields.DateField)
which I think should be used instead:
from wtforms.fields import DateField
class ExtendedConfirmRegisterForm(ConfirmRegisterForm):
name = TextField('Name',
[validators.Length(max=255),
validators.Required()])
surname = TextField('Surname',
[validators.Length(max=255)])
birth_date = DateField('Date of birth')
|
Why is requests.get() retrieving different HTML using Python than browser?
Question: I am attempting to extract data from an HTML table, but it appears that the
HTML isn't loading correctly when using `requests.get()`. Instead, a line in
the source reads:
> "JavaScript is not enabled and therefore this page may not function
> correctly."
When I navigate to the page in Google Chrome, the HTML appears as it should.
How do I get a Python script to load the proper HTML?
Answer: Welcome to the wonderful world of web-crawling. The problem you are
experiencing is that `requests.get()` would just get you the initial page that
the browser receives at the beginning of a page load. But, this is not the
page you see in the browser since there could be so much involved in forming
the web page: javascript function calls, AJAX calls etc.
If you want to programmatically get the HTML you see when you click "Show
source" in a web browser after the page was loaded - you would need a real
browser. This is there [`selenium`](http://selenium-python.readthedocs.org/)
could be a good option:
from selenium import webdriver
browser = webdriver.Firefox()
browser.get(url)
print browser.page_source
Note that `selenium` itself is very powerful in terms of [locating
elements](http://selenium-python.readthedocs.org/locating-elements.html) \-
you don't need a separate HTML parser for extracting the data out of the page.
Hope that helps.
|
Porting algorithm from Python to Go
Question: I am trying to port this python code to Go but there is no **beta()** in math
package. Where can i find beta and other functions required for this?
from numpy import *
from scipy.stats import beta
class BetaBandit(object):
def __init__(self, num_options=2, prior=(1.0,1.0)):
self.trials = zeros(shape=(num_options,), dtype=int)
self.successes = zeros(shape=(num_options,), dtype=int)
self.num_options = num_options
self.prior = prior
def add_result(self, trial_id, success):
self.trials[trial_id] = self.trials[trial_id] + 1
if (success):
self.successes[trial_id] = self.successes[trial_id] + 1
def get_recommendation(self):
sampled_theta = []
for i in range(self.num_options):
#Construct beta distribution for posterior
dist = beta(self.prior[0]+self.successes[i],
self.prior[1]+self.trials[i]-self.successes[i])
#Draw sample from beta distribution
sampled_theta += [ dist.rvs() ]
# Return the index of the sample with the largest value
return sampled_theta.index( max(sampled_theta) )
Answer: If you are talking about
[`numpy.random.beta`](http://docs.scipy.org/doc/numpy/reference/generated/numpy.random.beta.html),
the Beta distribution which is a special case of the Dirichlet distribution,
and is related to the Gamma distribution, you can check the project
[**`gostat`**](https://code.google.com/p/gostat/).
It has a [`beta.go` source
code](https://code.google.com/p/gostat/source/browse/stat/beta.go) which
implements that function.
|
Biopython SeqIO processing NNNNN in *.ab1 files
Question: Thanks for your help. I apologize in advance if there is a function built into
Biopython that handles this, I read the whole manual and couldn't find
anything.
**Goal:** Read in a raw sequencing file (*.ab1) and process using
sequence.seq.translate(11) However, I get this error -
"Bio.Data.CodonTable.TranslationError: Codon 'NNN' is invalid"
**My Solution:** I added an additional table to the CodonTable and commented
out the ambiguous checker in Bio.Data.CodonTable (had to do this to make it
work)
register_ncbi_table(
name = 'bacteria sequencing table',
alt_name = None,
id = 24,
table = {
'TTT': 'F', 'TTC': 'F', 'TTA': 'L', 'TTG': 'L', 'TCT': 'S',
'TCC': 'S', 'TCA': 'S', 'TCG': 'S', 'TAT': 'Y', 'TAC': 'Y',
'TGT': 'C', 'TGC': 'C', 'TGG': 'W', 'CTT': 'L', 'CTC': 'L',
'CTA': 'L', 'CTG': 'L', 'CCT': 'P', 'CCC': 'P', 'CCA': 'P',
'CCG': 'P', 'CAT': 'H', 'CAC': 'H', 'CAA': 'Q', 'CAG': 'Q',
'CGT': 'R', 'CGC': 'R', 'CGA': 'R', 'CGG': 'R', 'ATT': 'I',
'ATC': 'I', 'ATA': 'I', 'ATG': 'M', 'ACT': 'T', 'ACC': 'T',
'ACA': 'T', 'ACG': 'T', 'AAT': 'N', 'AAC': 'N', 'AAA': 'K',
'AAG': 'K', 'AGT': 'S', 'AGC': 'S', 'AGA': 'R', 'AGG': 'R',
'GTT': 'V', 'GTC': 'V', 'GTA': 'V', 'GTG': 'V', 'GCT': 'A',
'GCC': 'A', 'GCA': 'A', 'GCG': 'A', 'GAT': 'D', 'GAC': 'D',
'GAA': 'E', 'GAG': 'E', 'GGT': 'G', 'GGC': 'G', 'GGA': 'G',
'GGG': 'G', 'AAN': 'X', 'TAN': 'X', 'GAN': 'X', 'CAN': 'X',
'ATN': 'X', 'TTN': 'X', 'GTN': 'X', 'CTN': 'X', 'ACN': 'X',
'TCN': 'X', 'GCN': 'X', 'CCN': 'X', 'AGN': 'X', 'TGN': 'X',
'GGN': 'X', 'CGN': 'X', 'ANA': 'X', 'TNA': 'X', 'GNA': 'X',
'CNA': 'X', 'ANT': 'X', 'TNT': 'X', 'GNT': 'X', 'CNT': 'X',
'ANC': 'X', 'TNC': 'X', 'GNC': 'X', 'CNC': 'X', 'ANG': 'X',
'TNG': 'X', 'GNG': 'X', 'CNG': 'X', 'NAA': 'X', 'NTA': 'X',
'NGA': 'X', 'NCA': 'X', 'NAT': 'X', 'NTT': 'X', 'NGT': 'X',
'NCT': 'X', 'NAC': 'X', 'NTC': 'X', 'NGC': 'X', 'NCC': 'X',
'NAG': 'X', 'NTG': 'X', 'NGG': 'X', 'NCG': 'X', 'NNN': 'X',
'ANN': 'X', 'TNN': 'X', 'GNN': 'X', 'CNN': 'X', 'NAN': 'X',
'NTN': 'X', 'NGN': 'X', 'NCN': 'X', 'NNA': 'X', 'NNT': 'X',
'NNG': 'X', 'NNC': 'X', 'NNN': 'X'},
stop_codons = ['TAA', 'TAG', 'TGA'],
start_codons = ['TTG', 'CTG', 'ATT', 'ATC', 'ATA', 'ATG', 'GTG'])
**ambiguous checker**
for n in ambiguous_generic_by_id:
assert ambiguous_rna_by_id[n].forward_table["GUU"] == "V"
assert ambiguous_rna_by_id[n].forward_table["GUN"] == "V"
if n != 23 :
#For table 23, UUN = F, L or stop.
assert ambiguous_rna_by_id[n].forward_table["UUN"] == "X" # F or L
#R = A or G, so URR = UAA or UGA / TRA = TAA or TGA = stop codons
if "UAA" in unambiguous_rna_by_id[n].stop_codons and\
"UGA" in unambiguous_rna_by_id[n].stop_codons:
try:
print(ambiguous_dna_by_id[n].forward_table["TRA"])
assert False, "Should be a stop only"
except KeyError:
pass
assert "URA" in ambiguous_generic_by_id[n].stop_codons
assert "URA" in ambiguous_rna_by_id[n].stop_codons
assert "TRA" in ambiguous_generic_by_id[n].stop_codons
assert "TRA" in ambiguous_dna_by_id[n].stop_codons
del n
**Question 1:** I would prefer not to edit the root `CodonTable.py` file. Any
suggestions on how to avoid that?
**Question 2:** I really don't want to comment out the ambiguous checker. Can
someone help me write an exception to the ambiguous checker that will ignore
my new codon table?
Answer: When you load an ABI file, Biopython set the Seq alphabet as
`IUPACUnambiguousDNA()`. My first approach is to set the alphabet to
`SingleLetterAlphabet()`:
from Bio import SeqIO
from Bio.Alphabet import SingleLetterAlphabet
for rec in SeqIO.parse("prots.ab1", "abi", alphabet=SingleLetterAlphabet()):
print rec.seq.translate(11)
Now the seq translates with "X" and "N".
|
Fast and efficient way to detect if two images are visually identical in Python
Question: Given two images:
image1.jpg
image2.jpg
What's a fast way to detect if they are visually identical in Python? For
example, they may have different EXIF data which would yield different
checksums, even though the image data is the same).
Imagemagick has an excellent tool, "identify," that produces a visual hash of
an image, but it's very processor intensive.
Answer: Using PIL/Pillow:
from PIL import Image
im1 = Image.open('image1.jpg')
im2 = Image.open('image2.jpg')
if list(im1.getdata()) == list(im2.getdata()):
print "Identical"
else:
print "Different"
|
drmaa error with sun grid engine - No active session
Question: Hi I've installed gridengine on a 4-node cluster using the following command:
sudo apt-get install gridengine-client gridengine-qmon gridengine-exec gridengine-master
sudo apt-get install gridengine-exec gridengine-client
And it returned:
SGE_ROOT: /var/lib/gridengine
SGE_CELL: bms
I've therefore done all the necessary step to configure the gridengine and it
works.
However I want to run my job using python drmaa library and I've installed on
the master node:
sudo apt-get install libdrmaa-dev
pip install drmaa
So if i query the system with following script:
#!/usr/bin/env python
import drmaa
def main():
"""Query the system."""
s = drmaa.Session()
s.initialize()
print 'A DRMAA object was created'
print 'Supported contact strings: ' + s.contact
print 'Supported DRM systems: ' + str(s.drmsInfo)
print 'Supported DRMAA implementations: ' + str(s.drmaaImplementation)
print 'Version ' + str(s.version)
print 'Exiting'
s.exit()
if __name__=='__main__':
main()
It returns:
A DRMAA object was created
Supported contact strings: session=NGS-1.9217.1679116461
Supported DRM systems: GE 6.2u5
Supported DRMAA implementations: GE 6.2u5
Version 1.0
Exiting
But if I try to run a job with the script suggested by the link:
<http://code.google.com/p/drmaa-python/wiki/Tutorial#Running_a_Job>
It returns
drmaa.errors.NoActiveSessionException: code 5: No active session
Could anyone help me? What's wrong. The drmaa library looks like is able to
communicate with gridengine but it cannot run a job. Why it raise this error?
I would really appreciate any kind of help.
Answer: you will find that the example of running job using DRMAA does not initialize
the session so just add s.initialize() after creating new session s =
drmaa.Session() as following:
#!/usr/bin/env python
import drmaa
import os
def main():
"""Submit a job.
Note, need file called sleeper.sh in current directory.
"""
s = drmaa.Session()
s.initialize()
print 'Creating job template'
jt = s.createJobTemplate()
jt.remoteCommand = os.getcwd() + '/sleeper.sh'
jt.args = ['42','Simon says:']
jt.joinFiles=True
jobid = s.runJob(jt)
print 'Your job has been submitted with id ' + jobid
print 'Cleaning up'
s.deleteJobTemplate(jt)
s.exit()
if __name__=='__main__':
main()
|
How can I log a functions arguments in a reusable way in Python?
Question: I've found myself writing code like this several times:
def my_func(a, b, *args, **kwargs):
saved_args = locals() # Learned about this from http://stackoverflow.com/a/3137022/2829764
local_var = "This is some other local var that I don't want to log"
try:
a/b
except Exception as e:
logging.exception("Oh no! My args were: " + str(saved_args))
raise
Running `my_func(1, 0, "spam", "ham", my_kwarg="eggs")` gives this output on
stderr:
ERROR:root:Oh no! My args were: {'a': 1, 'args': (u'spam', u'ham'), 'b': 0, 'kwargs': {'my_kwarg': u'eggs'}}
Traceback (most recent call last):
File "/Users/kuzzooroo/Desktop/question.py", line 17, in my_func
a/b
ZeroDivisionError: division by zero
My question is, can I write something reusable so that I don't have to save
locals() at the top of the function? And can it be done in a nice Pythonic
way?
EDIT: one more request in response to @mtik00: ideally I'd like some way to
access saved_args or the like from within my_func so that I can do something
other than log uncaught exceptions (maybe I want to catch the exception in
my_func, log an error, and keep going).
Answer: **Decorators** are what you are looking for. Here's an example:
import logging
from functools import wraps
def arg_logger(func):
@wraps(func)
def new_func(*args, **kwargs):
saved_args = locals()
try:
return func(*args, **kwargs)
except:
logging.exception("Oh no! My args were: " + str(saved_args))
raise
return new_func
@arg_logger
def func(arg1, arg2):
return 1 / 0
if __name__ == '__main__':
func(1, 2)
Here, I'm using arg_logger() as a _decorator_. Apply the decorator to any
function you want to have this new behavior.
There's a good discussion about decorators
[here](http://en.wikipedia.org/wiki/Python_syntax_and_semantics#Decorators).
|
python button does not work when image is added
Question: When I try to add and image to the button, the program will run, but the
button will be blank and you cannot click on it. If I change
`image=Tkinter.PhotoImage(file="C:/TeDOC/OpenFolder.gif")` to `text='Open
Directory` it works fine and you are able to click the button. I have no idea
why when I change it to an img, it does not work. Any help will be
appreciated.
Here is my code:
import Tkinter, Tkconstants, tkFileDialog
class TkFileDialogExample(Tkinter.Frame):
def __init__(self, root):
Tkinter.Frame.__init__(self, root)
# options for buttons
button_opt = {'fill': Tkconstants.BOTH, 'padx': 5, 'pady': 5}
# define buttons
Tkinter.Button(self, image=Tkinter.PhotoImage(file="C:/TeDOC/OpenFolder.gif"), command=self.askdirectory).pack(**button_opt)
# defining options for opening a directory
self.dir_opt = options = {}
options['initialdir'] = 'C:\\'
options['mustexist'] = False
options['parent'] = root
options['title'] = 'This is a title'
def askdirectory(self):
#Returns a selected directoryname.
return tkFileDialog.askdirectory(**self.dir_opt)
if __name__=='__main__':
root = Tkinter.Tk()
TkFileDialogExample(root).pack()
root.mainloop()
Answer: First you have to define your image, using the self.image. So try:
self.image = Tkinter.PhotoImage(file="C:/TeDOC/OpenFolder.gif")
Then under your button, put:
Tkinter.Button(self, image=self.image, command=self.askdirectory).pack(**button_opt)
|
Continuing code after executing a File - Python
Question: I have made a Simple GUI that launches when i run my Twitch TV IRC Bot. But,
the main bot doesn't continue until after i close the GUI. How would i make it
so the Script runs at the same time as the GUI? This is the GUI:
##--GUI--##
def whitelist_wipe():
execfile('command_whitelist_wipe.py')
def modpack():
modpack = modpack_input.get()
return
root = Tk()
modpack_input = StringVar()
root.title('Geekster_Bot')
root.geometry('450x450+500+300')
WhitelistButton = Button(root, text = 'Clear Whitelist!', command + whitelist_wipe).pack()
SubmitButton = Button(root, text = 'Change Modpack', command = modpack).pack()
ModpackName = Entry(root, textvariable=modpack_input).pack()
root.mainloop()
This is the part where it launches the GUI from the main Bot scrpit:
try:
execfile('GUI.py')
except:
print('Error loading GUI')
How would i continue the code with the GUI open?
EDIT
GUI.py;
##--GUI--##
def whitelist_wipe():
execfile('command_whitelist_wipe.py')
def modpack_var():
modpack_input = modpack_user.get()
root = Tk()
modpack_user = StringVar()
root.title('Geekster_Bot')
root.geometry('350x100+500+300')
Label1 = Label(root, text = 'Geekster_Bot Controls!').pack()
WhitelistButton = Button(root, text = 'Clear Whitelist!', command =whitelist_wipe).pack(side = LEFT)
SubmitButton = Button(root, text = 'Change Modpack', command = modpack_var).pack()
ModpackName = Entry(root, textvariable=modpack_user).pack()
root.mainloop()
Main Bot;
try:
#Create thread
gui_thread = threading.Thread( target = execfile, args = ('GUI.py',) )
#Start thread
gui_thread.start()
#Code to run in the main thread
except:
print('Error loading GUI')
def message(msg): #function for sending messages to the IRC chat
global queue
queue = queue + 1
print queue
if queue < 20: #ensures does not send >20 msgs per 30 seconds.
twitch = ('OUTPUT ON ' + channel + ' :' + msg + '\r\n')
irc.send('PRIVMSG ' + channel + ' :' + msg + '\r\n')
print (twitch)
else:
print 'Message deleted'
def socialtimer(): #function for announcing social every 3 minutes
global ntimer
z = open(r'E:\Geekster_Bot\Twitter.txt')
SOCIAL = z.read()
message (SOCIAL)
print 'Social Timers Started!'
ntimer = threading.Timer(1200,socialtimer)
ntimer.start()
def queuetimer(): #function for resetting the queue every 30 seconds
global queue
print 'queue reset'
queue = 0
threading.Timer(30,queuetimer).start()
def modpack_var():
modpack_input = modpack_user.get()
##--Main Bot--##
#General variables
newsmsg = 'whitelist'
modpack = modpack_input
Answer: Since the gui itself runs in a loop it blocks the thread you start it in until
you stop the loop (close the gui). You need to start the gui in a different
thread from the main one.
You can do this using the threading module:
import threading
try:
#Create thread
gui_thread = threading.Thread( target = execfile, args = ('GUI.py',) )
#Start thread
gui_thread.start()
#Code to run in the main thread
except:
print('Error loading GUI')
In this code the `gui_thread` object is a thread, which runs the `execfile`
callable (a function in this case) with the parameter `'GUI.py'` on start.
Check the threading module documentation for further info:
<https://docs.python.org/3.3/library/threading.html>
|
psutil - getting process name is blank
Question: I'm trying to run this code and I'm not getting the list of processes by name:
import psutil
PROCNAME = "python.exe"
for proc in psutil.process_iter():
if proc.name == PROCNAME:
print proc
What I get is nothing even though the process is running.
Answer: I was experiencing the same problem. Changing `proc.name` to `proc.name()`
solved it for me if anyone else was having similar issues.
|
Create a Student-Age graph in Python-Matplotlib
Question:
import matplotlib.pyplot as plt
x = ['Eric','Jhon','bill','Daniel']
y = [10, 17, 12.5, 20]
plt.plot(x,y)
plt.show()
When I run this code, I get this error `ValueError: could not convert string
to float:`
I want all names in list `x` at x-axis and corresponding ages are in second
list `y` which will be used in bar graph.
So here I have 1 more question Is it a good way to do in my case(I mean if we
can create a list of tuples(name,age)) and that would be easy?? or something
else.
Answer: The error occurs because matplotlib is expecting numerical data but you're
providing strings (the names).
What you can do instead is plot your data using some numerical data and then
replace the ticks on the x-axis using
[`plt.xticks`](http://matplotlib.org/1.3.1/api/pyplot_api.html#matplotlib.pyplot.xticks)
as below.
import matplotlib.pyplot as plt
names = ['Eric','John','Bill','Daniel']
x = range(len(names))
y = [10, 17, 12.5, 20]
plt.plot(x, y)
plt.xticks(x, names)
plt.show()
|
Comparing two strings in Python - depends on string source...?
Question: I have the following python script:
import sys
import io
str1 = 'asd'
str2 - 'asd'
if (str2.find(str1)==-1):
print('FALSE')
else:
print('TRUE')
#Prints "TRUE"
It works fine. No problem. The problem starts if I take the string, put it in
a file (save it) and then read the content of the file to str1 and str2, like
so:
import sys
import io
fHandler = open(r'C:\dev\1.pub','r')
str1 = fHandler.read()
str2 = fHandler.read()
if (str2.find(str1)==-1):
print('FALSE')
else:
print('TRUE')
#Prints "FALSE"
Why is the behaviour different?
Thanks!
Answer: If you try to call `fHandler.read()` twice, then the second one will return n
empty string (or empty bytes if you read binary). `fHandler.read()` reads
everything until the end and the second call will start reading at the end
until the end, so it returns an empty string. Try adding `fHandler.seek(0)`
beetween your function calls and it should work.
|
How to execute sql Python script in Windows command Prompt?
Question: I have a simple script that uses sqlite3 in Python.
However, when I run this from cmd.exe in Windows I get an "Open With" window.
If I click 'cancel' it says "Access is denied." in cmd.exe.
import sqlite3
connection = sqlite3.connect("test_database.db")
c = connection.cursor()
c.execute("CREATE TABLE People(FirstName TEXT, LastName TEXT, Age INT)")
c.execute("INSERT INTO People VALUES('Ron','Obvious',42)")
connection.commit()
connection.close()
I can run Python scripts fine from cmd.exe. I just have this problem because
I'm using sqlite?
(Also, I have the sqlite path in PATH)
How can I stop this "Open with" window appearing, and actually get my script
to run correctly from cmd.exe?
Answer: Running myscript.py in cmd does not work if I use import sqlite. Instead, I
ran "python myscript.py" and the script runs fine.
Thanks to @nerdwaller.
|
Check whether an entry present in python list and add the elements
Question: I have two python list of the form
list1 = [('TGFB1', 'TGFB1', 1), ('TGFB1', 'CRP', 0.4),('BRCA2', 'TP53', 0.3)]
list2 = [('BRCA1', 'TP53', 2), ('TGFB1', 'CRP', 0.4),('BRCA2', 'TP53', 0.3)]
I need to check whether each entry in list2 is present in list1 . If present
add the integer part and store in a new list. If not present just append that
entry to the newly created list. So here my newly created list3 should look
like
list3 = [('TGFB1', 'TGFB1', 1), ('TGFB1', 'CRP', 0.8),('BRCA2', 'TP53', 0.6),('BRCA1', 'TP53', 2) ]
Answer: Following my above comment, this is what you might want:
from copy import copy
d3 = copy(dict(((x, y), z) for x, y, z in list1))
d2 = dict(((x, y), z) for x, y, z in list2)
for key, value in d2.iteritems():
d3[key] = (d3[key] if key in d3 else 0.0) + value
If you do really want to turn `d3` then back to a list of the same structure
use:
list3 = [key + (value,) for key, value in d3.iteritems()]
|
What is the canonical way to check if a function has been called in Python unittest without use of a mock?
Question: If I have a class similar to the 1 below and I want to test the various cases
for the bar function, how can I accomplish this without mocking the private
functions? In other words, how in Python's unittest library could I achieve
something similar to this:
def test_bar():
f = Foo()
f.bar(3)
expect(self._is_positive_number).toBeCalled()
**foo.py**
class Foo():
def bar(self, x):
if type(x) is not int:
print('Please enter a valid integer')
return False
if x > 0:
self._is_positive_number()
elif x == 0:
self._is_zero()
else
self._is_negative()
def _is_positive_number(self):
print('Positive')
return True
def _is_zero(self):
print('Zero')
return True
def _is_negative_number(self):
print('Negative')
return True
Answer: As far as I know, there's no way to do this without mocking out the private
methods. However, the `mock` library (available as `unittest.mock` in the
standard library as of 3.3, a separate installation otherwise) makes this
relatively painless:
try:
# Python 3.3 or later
import unittest.mock as mock
except ImportError:
# Make sure you install it first
import mock
class TestFoo(unittest.TestCase):
def setUp(self):
self.f = Foo()
def test_bar(self):
with mock.patch.object(self.f, '_is_positive_number') as is_pos:
self.f.bar(3)
self.assertTrue(is_pos.called)
|
Create a matrix of tf-idf values
Question: I have a set of `documents` like:
D1 = "The sky is blue."
D2 = "The sun is bright."
D3 = "The sun in the sky is bright."
and a set of `words` like:
"sky","land","sea","water","sun","moon"
I want to create a matrix like this:
x D1 D2 D3
sky tf-idf 0 tf-idf
land 0 0 0
sea 0 0 0
water 0 0 0
sun 0 tf-idf tf-idf
moon 0 0 0
Something like the example table given here:
<http://www.cs.duke.edu/courses/spring14/compsci290/assignments/lab02.html>.
In the given link, it uses the same words from the document but I need to use
the set of `words` that I have mentioned.
If the particular word is present in the document then I put the `tf-idf`
values, else I put a `0` in the matrix.
Any idea how I might build some sort of matrix like this? Python will be best
but R also appreciated.
I am using the following code but am not sure whether I am doing the right
thing or not. My code is:
from sklearn.feature_extraction.text import CountVectorizer
from sklearn.feature_extraction.text import TfidfTransformer
from nltk.corpus import stopwords
train_set = "The sky is blue.", "The sun is bright.", "The sun in the sky is bright." #Documents
test_set = ["sky","land","sea","water","sun","moon"] #Query
stopWords = stopwords.words('english')
vectorizer = CountVectorizer(stop_words = stopWords)
#print vectorizer
transformer = TfidfTransformer()
#print transformer
trainVectorizerArray = vectorizer.fit_transform(train_set).toarray()
testVectorizerArray = vectorizer.transform(test_set).toarray()
#print 'Fit Vectorizer to train set', trainVectorizerArray
#print 'Transform Vectorizer to test set', testVectorizerArray
transformer.fit(trainVectorizerArray)
#print
#print transformer.transform(trainVectorizerArray).toarray()
transformer.fit(testVectorizerArray)
#print
tfidf = transformer.transform(testVectorizerArray)
print tfidf.todense()
I am getting very absurd results like this (values are only `0` and `1` while
I am expecting values between 0 and 1).
[[ 0. 0. 1. 0.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 1.]
[ 0. 0. 0. 0.]
[ 1. 0. 0. 0.]]
I am also open to other libraries for calculating `tf-idf`. I just want a
correct matrix which I mentioned above.
Answer: A R solution could look like this:
library(tm)
docs <- c(D1 = "The sky is blue.",
D2 = "The sun is bright.",
D3 = "The sun in the sky is bright.")
dict <- c("sky","land","sea","water","sun","moon")
mat <- TermDocumentMatrix(Corpus(VectorSource(docs)),
control=list(weighting = weightTfIdf,
dictionary = dict))
as.matrix(mat)[dict, ]
# Docs
# Terms D1 D2 D3
# sky 0.5849625 0.0000000 0.2924813
# land 0.0000000 0.0000000 0.0000000
# sea 0.0000000 0.0000000 0.0000000
# water 0.0000000 0.0000000 0.0000000
# sun 0.0000000 0.5849625 0.2924813
# moon 0.0000000 0.0000000 0.0000000
|
Asserting execution order in python unittest
Question: I have a function that creates a temporary directory, switches to that
temporary directory, performs some work, and then switches back to the
original directory. I am trying to write a unit test that tests this. I don't
have a problem verifying that the current directory was changed to the temp
dir and changed back again, but I'm having a problem verifying that the
important stuff took place in between those calls.
My original idea was to abstract the function into three sub functions so that
I could test the call order. I can replace each of the three sub functions
with mocks to verify that they are called -- however, I am still presented
with the issue of verifying the order. On a mock I can use assert_has_calls,
but upon what object do I call that function?
Here is the class I'm trying to test:
import shutil
import os
import subprocess
import tempfile
import pkg_resources
class Converter:
def __init__(self, encoded_file_path):
self.encoded_file_path = encoded_file_path
self.unencoded_file_path = None
self.original_path = None
self.temp_dir = None
def change_to_temp_dir(self):
self.original_path = os.getcwd()
self.temp_dir = tempfile.mkdtemp()
os.chdir(self.temp_dir)
def change_to_original_dir(self):
os.chdir(self.original_path)
shutil.rmtree(self.temp_dir)
def do_stuff(self):
pass
def run(self):
self.change_to_temp_dir()
self.do_stuff()
self.change_to_original_dir()
This is as far as I got writing the test case:
def test_converter(self, pkg_resources, tempfile, subprocess, os, shutil):
encoded_file_path = Mock()
converter = Converter(encoded_file_path)
converter.change_to_temp_dir = Mock()
converter.do_stuff= Mock()
converter.change_to_original_dir = Mock()
assert converter.encoded_file_path == encoded_file_path
assert converter.unencoded_file_path is None
converter.run()
Now that I have each function mocked, I can verify THAT they were called, but
not in what ORDER. How do I go about doing this?
Answer: One workaround would to be to create a separate mock object, attach methods to
it and use
[`assert_has_calls()`](http://www.voidspace.org.uk/python/mock/mock.html#mock.Mock.assert_has_calls)
to check the call order:
converter = Converter(encoded_file_path)
converter.change_to_temp_dir = Mock()
converter.do_stuff = Mock()
converter.change_to_original_dir = Mock()
m = Mock()
m.configure_mock(first=converter.change_to_temp_dir,
second=converter.do_stuff,
third=converter.change_to_original_dir)
converter.run()
m.assert_has_calls([call.first(), call.second(), call.third()])
|
How do I keep the focus on the command prompt when calling pylab.show?
Question: I am calling a python script from the comandline (bash under Ubuntu):
> python myScript.py
within this script, I create a figure, show it (nonblocking) with PyLab and
wait for a user entry:
import matplotlib as mpl
mpl.use('TkAgg')
import pylab as pl
fig = pylab.figure()
# Figure gets some content here
pl.show(block=False)
inp = raw_input('Please enter your choice: ') # Prompt window has no focus
Now my problem is, that the figure window, that is poping up, has the focus.
But I want the focus to stay at or return to the command line window for
interaction with the raw_input...
Any suggestions how to achieve this?
Thanks in advance!
Answer: Some other lower level backends tend not to do it, try:
import matplotlib as mpl
mpl.use('Agg')
|
Spyder SymPy Wont Print Symbolic Math
Question: I setup Anaconda 2.0.0 (Win 64). It has SymPy 0.7.5.
I configured Spyder (2.3.0rc that came with Anaconda) to use symbolic math:
_Tools > Preferences > iPython console > Advanced Settings > Symbolic
Mathematics_
I create a new project and a new file:
# -*- coding: utf-8 -*-
from sympy import *
init_printing(use_unicode=False, wrap_line=False, no_global=True)
x = Symbol('x')
integrate(x, x)
print("Completed.")
When I run this (Python or iPython console) it does not print the integral --
it only prints _Completed._
But what is weird is that while in the console that just did the run if I then
re-type:
integrate(x, x)
It does print the integral.
So running from a file never prints any symbolic math but typing in the
console manually does?
Can anyone help with this issue -- maybe it some sort of configuration?
Thank you!
Answer: Running a script is not the same as executing code in IPython. When you run
the code in a cell or prompt in IPython, it captures the output of the last
command and displays it to you. When you run a script, the script is just run,
and the only thing that is displayed is what is printed to the screen.
I don't think there is a way to send the IPython display object (which would
be needed to get pretty latex output) from a script, but I may be
misunderstanding how spyder executes the code in IPython, or missing some
hooks that it has. You can try
from IPython.display import display
display(integrate(x, x))
|
Merging two Excel files by ID and combining columns with same name (python, pandas)
Question: I am new to stackoverflow and pandas for python. I found part of my answer in
the post [Looking to merge two Excel files by ID into one Excel file using
Python 2.7](http://stackoverflow.com/questions/17661836/looking-to-merge-two-
excel-files-by-id-into-one-excel-file-using-python-2-7)
However, I also want to merge or combine columns from the two excel files with
the same name. I thought the following post would have my answer but I guess
it's not titled correctly: [Merging Pandas DataFrames with the same column
name](http://stackoverflow.com/questions/20862068/merging-pandas-dataframes-
with-the-same-column-name)
Right now I have the code:
import pandas as pd
file1 = pd.read_excel("file1.xlsx")
file2 = pd.read_excel("file2.xlsx")
file3 = file1.merge(file2, on="ID", how="outer")
file3.to_excel("merged.xlsx")
file1.xlsx
ID,JanSales,FebSales,test
1,100,200,cars
2,200,500,
3,300,400,boats
file2.xlsx
ID,CreditScore,EMMAScore,test
2,good,Watson,planes
3,okay,Thompson,
4,not-so-good,NA,
what I get is merged.xlsx
ID,JanSales,FebSales,**test_x** ,CreditScore,EMMAScore,**test_y**
1,100,200,cars,NaN,NaN,
2,200,500,,good,Watson,planes
3,300,400,boats,okay,Thompson,
4,NaN,NaN,,not-so-good,NaN,
what I want is merged.xlsx
ID,JanSales,FebSales,CreditScore,EMMAScore,**test**
1,100,200,NaN,NaN,cars
2,200,500,good,Watson,planes
3,300,400,okay,Thompson,boats
4,NaN,NaN,not-so-good,NaN,NaA
In my real data, there are 200+ columns that correspond to the "test" column
in my example. I want the program to find these columns with the same names in
both file1.xlsx and file2.xlsx and combine them in the merged file.
Answer: OK, here is a more dynamic way, after merging we assume that clashes will
occur and result in 'column_name_x' or '_y'.
So first figure out the common column names and remove 'ID' from this list
In [51]:
common_columns = list(set(list(df1.columns)) & set(list(df2.columns)))
common_columns.remove('ID')
common_columns
Out[51]:
['test']
Now we can iterate over this list to create the new column and use `where` to
conditionally assign the value dependent on which value is not null.
In [59]:
for col in common_columns:
df3[col] = df3[col+'_x'].where(df3[col+'_x'].notnull(), df3[col+'_y'])
df3
Out[59]:
ID JanSales FebSales test_x CreditScore EMMAScore test_y test
0 1 100 200 cars NaN NaN NaN cars
1 2 200 500 NaN good Watson planes planes
2 3 300 400 boats okay Thompson NaN boats
3 4 NaN NaN NaN not-so-good NaN NaN NaN
[4 rows x 8 columns]
Then just to finish off drop all the extra columns:
In [68]:
clash_names = [elt+suffix for elt in common_columns for suffix in ('_x','_y') ]
clash_names
df3.drop(labels=clash_names, axis=1,inplace=True)
df3
Out[68]:
ID JanSales FebSales CreditScore EMMAScore test
0 1 100 200 NaN NaN cars
1 2 200 500 good Watson planes
2 3 300 400 okay Thompson boats
3 4 NaN NaN not-so-good NaN NaN
[4 rows x 6 columns]
The snippet above is from this :[Prepend prefix to list elements with list
comprehension](http://stackoverflow.com/questions/3330880/prepend-prefix-to-
list-elements-with-list-comprehension)
|
Dynamically assign values - python
Question: looking to improve the efficiency of my code, as while my current method
works, i feel it can be improved
currently this is my code :
if ouroraddrlen == (4,):
ouropip = struct.unpack(">bbbb", payload[6:10]) # Need to change this to accept ipv6 as well
print "Our I.P : ", ouropip
notheirip = struct.unpack(">b", payload[10])
print "No. of their I.P's : ", notheirip
theiroripv = struct.unpack(">b", payload[11])
print "Their I.P version:: ", theiroripv
theiroraddrlen = struct.unpack(">b", payload[12])
print "Length of their Ip : ", theiroraddrlen
theirfirstip = struct.unpack(">bbbb", payload[13:17])
print "First Ip : ", theirfirstip
theirsecondip = struct.unpack(">bbbb", payload[18:22])
print "Second Ip : ", theirsecondip
the output is :
Time : (1401734263,)
Our onion address :
Ip version : (4,)
Ip length : (4,)
Our I.P : ( )
No. of their I.P's : (2,)
Their I.P version:: (4,)
Length of their Ip : (4,)
First Ip : ( )
Second Ip : ( )
i have removed the real ip's but they are just ipv4 addresses
however what i am wondering, is if it is possible to include an if statement
after this section of code :
notheirip = struct.unpack(">b", payload[10])
print "No. of their I.P's : ", notheirip
where if the notheirip is greater than zero and depending on the length of :
theiroraddrlen = struct.unpack(">b", payload[12])
print "Length of their Ip : ", theiroraddrlen
which would be either 4 or 16 then it would set the payload values of the next
section
for example if notheirip = (2,) and theiroraddrlen = (4,) then i would want it
to print out
theirip = struct.unpack(">b << the number of b required so either 4 or 16 and
then the range, this will always start at 13 and go up to either 4 or 16 in
the future and loop until all the ip's are displayed
not sure if that is clear but hopefully it is :)
Thanks
Answer:
>>> from collections import namedtuple
>>> Record = namedtuple("Record","IP NoIP IPV LenIP FirstIP SecondIP")
>>> Record._asdict(Record._make(struct.unpack(">LbbbLL",payload[6:])))
{'FirstIP': 1145324612, 'NoIP': 17, 'SecondIP': 1431655765, 'IP': 3140690449L,
IPV': 34, 'LenIP': 51}
>>>
I think would work (you might want different 4 byte type than L) (keep in mind
i totally made up the payload so I would expect different results with a real
one)
if you want to get 4 digit tuples for the ips just unpack the new value
new_record["IP"] = stuct.unpack("bbbb",new_record["IP"])
|
Python ginput not allowing new points to be plotted
Question: This code asks the user to digitize three points (using ginput), then should
plot those points to the screen atop the imshow plot. It does not. Any ideas
why?
from pylab import show, ginput, rand, imshow, plot
from matplotlib.figure import Figure
import numpy as np
x1 = rand(103, 53)
figure = Figure(figsize=(4, 4), dpi=100)
axes = figure.add_subplot(111)
imshow(x1)
# Get user input
x = ginput(3)
x = np.array(x)
# Plot the user's points to the screen
plot(x[:, 0], x[:, 1], 'k*', ms=50)
show()
Answer: Not sure which way you are trying to plot, the star and the background or vice
versa but you need to change the order of your calls.
plot(10, 30, 'k*', ms=100)
x = ginput(2)
imshow(x1)
show()
This will show a star then when you click two points show your rand data.
This is a nice example of using ginput taken from
[here](http://matplotlib.org/examples/pylab_examples/ginput_manual_clabel.html):
import time
import numpy as np
import matplotlib.pyplot as plt
def tellme(s):
print(s)
plt.title(s,fontsize=16)
plt.draw()
##################################################
# Define a triangle by clicking three points
##################################################
plt.clf()
plt.axis([-1.,1.,-1.,1.])
plt.setp(plt.gca(),autoscale_on=False)
tellme('You will define a triangle, click to begin')
plt.waitforbuttonpress()
happy = False
while not happy:
pts = []
while len(pts) < 3:
tellme('Select 3 corners with mouse')
pts = np.asarray( plt.ginput(3,timeout=-1) )
if len(pts) < 3:
tellme('Too few points, starting over')
time.sleep(1) # Wait a second
ph = plt.fill( pts[:,0], pts[:,1], 'r', lw=2 )
tellme('Happy? Key click for yes, mouse click for no')
happy = plt.waitforbuttonpress()
# Get rid of fill
if not happy:
for p in ph: p.remove()
|
Skip subdirectory in python import
Question: Ok, so I'm trying to change this:
app/
- lib.py
- models.py
- blah.py
Into this:
app/
- __init__.py
- lib.py
- models/
- __init__.py
- user.py
- account.py
- banana.py
- blah.py
And still be able to import my models using `from app.models import User`
rather than having to change it to `from app.models.user import User` all over
the place. Basically, I want everything to treat the package as a single
module, but be able to navigate the code in separate files for development
ease.
The reason I can't do something like add `for file in __all__: from file
import *` into **init**.py is I have circular references between the model
files. A fix I don't want is to import those models from within the functions
that use them. But that's super ugly. Let me give you an example:
user.py
...
from app.models import Banana
...
banana.py
...
from app.models import User
...
I wrote a quick pre-processing script that grabs all the files, re-writes them
to put imports at the top, and puts it into models.py, but that's hardly an
improvement, since now my stack traces don't show the line number I actually
need to change.
Any ideas? I always though **init** was probably magical but now that I dig
into it, I can't find anything that lets me provide myself this really simple
convenience.
Answer: It depends on what your circular references are for. If you have a class in
user that inherits from Banana and a class in banana that inherits from User,
you can't do this. You also can't do it if each class defines a decorator that
gets used in the other or anything else that gets called during the actual
import.
You can, however, if you are just mutually referencing helper functions, or if
your User object has a method to create new instances of Banana and your
Banana object has a method that creates new instances of User. As long as the
mutual reference doesn't actually get used until something in the module is
called from outside it, then in your model folder, in `__init__.py`, you can
just do something like:
import user
import banana
#etc...
user.banana = banana
banana.user = user
#etc...
User = user.User
Banana = banana.Banana
Then for sake of clarity and not trying to figure out what's going on
|
How to extract the string values "Hello" and "World" from the XML using Python 2.6
Question: I need to extract the strings "Hello" and "World" using Python 2.6. Please
advice.
<Translate_Array_Request>
<App_Id />
<From>language-code</From>
<Options>
<Category xmlns="http://schemas.datacontract.org/2004/07/Microsoft.MT.Web.Service.V2" >string-value</Category>
<Content Type xmlns="http://schemas.datacontract.org/2004/07/Microsoft.MT.Web.Service.V2">text/plain</ContentType>
<Reserved Flags xmlns="http://schemas.datacontract.org/2004/07/Microsoft.MT.Web.Service.V2" />
<State xmlns="http://schemas.datacontract.org/2004/07/Microsoft.MT.Web.Service.V2" >int-value</State>
<Uri xmlns="http://schemas.datacontract.org/2004/07/Microsoft.MT.Web.Service.V2" >string-value</Uri>
<User xmlns="http://schemas.datacontract.org/2004/07/Microsoft.MT.Web.Service.V2" >string-value</User>
</Options>
<Texts>
<string xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays">**Hello**</string>
<string xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays">**World**</string>
</Texts>
<To>language-code</To>
</Translate_Array_Request>
Answer: There are multiple libraries in python that let you parse and extract data
from XML. One way would be to use the [ElementTree XML python
API](https://docs.python.org/2/library/xml.etree.elementtree.html). Assuming
the input is saved as a string `xml_data`, this is what you do:
>>> import xml.etree.ElementTree as ET
>>> root = ET.fromstring(xml_data)
>>> texts = root.find('Texts')
>>> for data in texts:
... print data.text
...
**Hello**
**World**
|
How do I get the "biggest" path?
Question: I need to write some Python code to get the latest version of Android from a
path. For example:
$ ls -l android_tools/sdk/platforms/
total 8
drwxrwxr-x 5 deqing deqing 4096 Mar 21 11:42 android-18
drwxrwxr-x 5 deqing deqing 4096 Mar 21 11:42 android-19
$
In this case I'd like to have `android_tools/sdk/platforms/android-19`.
Answer: The [`max` function](https://docs.python.org/2.7/library/functions.html#max)
can take a `key=myfunc` parameter to specify a function that will return a
comparison value. So you could do something like:
import os, re
dirname = 'android_tools/sdk/platforms'
files = os.listdir(my_dir)
def mykeyfunc(fname):
digits = re.search(r'\d+$', fname).group()
return int(digits)
print max(files, mykeyfunc)
Adjust that regular expression as needed for the actual files you're dealing
with, and that should get you started.
|
python error in get trending topic using tweepy
Question: I am trying to get top 20 trending topic through twitter api based on the
Tweepy library.
Here is my python code:
import tweepy
import json
import time
today = time.strftime("%Y-%m-%d")
CONSUMER_KEY = ""
CONSUMER_SECRET = ""
ACCESS_KEY = ""
ACCESS_SECRET = ""
auth = tweepy.OAuthHandler(CONSUMER_KEY, CONSUMER_SECRET)
auth.set_access_token(ACCESS_KEY, ACCESS_SECRET)
api = tweepy.API(auth)
trends = api.trends_daily(today)
print trends
I am using trends_daily function to get the top 20 trending topics for each
day.
The variable "today" is in **date format** : `today =
time.strftime("%Y-%m-%d")`. And I tried string format as well. However, it
keeps report error message:
File "/Users/Ivy/PycharmProjects/TwitterTrend/trends.py", line 17, in <module>
trends = api.trends_daily("2014-06-03")
File "build/bdist.macosx-10.9-intel/egg/tweepy/binder.py", line 230, in _call
File "build/bdist.macosx-10.9-intel/egg/tweepy/binder.py", line 203, in execute
tweepy.error.TweepError: [{u'message': u'Sorry, that page does not exist', u'code': 34}]
Answer: I believe that you're using tweepy version 1 which is [no longer
supported](https://dev.twitter.com/docs/api/1/get/trends/daily):
<https://api.twitter.com/1/trends/daily.json>
Try to re-install (version 1.1), for example:
<https://api.twitter.com/1.1/trends/available.json>
|
Argparse mutally exclusive by subgrouping
Question: Currently the argparse of my code gives the following:
usage: ir.py [-h] [-q | --json | -d ]
Some text
optional arguments:
-h, --help show this help message and exit
-q gene query terms (e.g. mcpip1)
--json output in JSON format, use only with -q
-d , --file_to_index file to index
What I want it to do is the following:
1. `-q` should be mutually exclusive from `-d`
2. and `--json` should only go with `-q`
What's the way go go about it? This is my argparse code:
parser = argparse.ArgumentParser(description='''Some text''')
group = parser.add_mutually_exclusive_group()
group.add_argument("-q",help="gene query terms (e.g. mcpip1)",metavar="",type=str)
group.add_argument("--json", help="output in JSON format, use only with -q", action="store_true")
group.add_argument("-d","--file_to_index", help="file to index",metavar="",type=str)
args = parser.parse_args()
It currently rejects `-q` with `--json`:
python ir.py --json -q mcpip1
usage: ir.py [-h] [-q | --json | -d ]
ir.py: error: argument -q: not allowed with argument --json
Answer: `-q` and `-d` aren't really options (presumably, one them is required);
they're subcommands, so you should use the subparser feature of `argparse` to
create two subcommands `query` and `index`, and associate `--json` only with
the `query` subcommand.
import argparse
parser = argparse.ArgumentParser(description='''Some text''')
subparsers = parser.add_subparsers()
query_p = subparsers.add_parser("query", help="Query with a list of terms")
query_p.add_argument("terms")
query_p.add_argument("--json", help="output in JSON format, use only with -q", action="store_true")
index_p = subparsers.add_parser("index", help="index a file")
index_p.add_argument("indexfile", help="file to index")
args = parser.parse_args()
Help for the overall program is available with
ir.py -h
Help for each subcommand is displayed separately
ir.py query -h
ir.py index -h
Usage would be something like
ir.py query "list of terms"
ir.py query --json "list of terms"
ir.py index somefile.ext
|
ImportError: No module named ui_imagedialog
Question: I am new to pyQt4. First I installed pyqt4 then installed QTDesigner. And
tried to run the given program( From internet). The file is named as main.py
import sys
from PyQt4.QtGui import QApplication, QDialog
from ui_imagedialog import Ui_ImageDialog
app = QApplication(sys.argv)
window = QDialog()
ui = Ui_ImageDialog()
ui.setupUi(window)
window.show()
sys.exit(app.exec_())
run the program using terminal
python main.py
I got the following error
from ui_imagedialog import Ui_ImageDialog
ImportError: No module named ui_imagedialog
How to solve this??
Answer: You could try running this instead;
import sys
from PyQt4.QtGui import QApplication, QDialog
app = QApplication(sys.argv)
window = QDialog()
window.show()
sys.exit(app.exec_())
And if you are using PyQt5, use this;
import sys
from PyQt5.QtWidgets import QApplication, QDialog
app = QApplication(sys.argv)
window = QDialog()
window.show()
sys.exit(app.exec_())
This will produce an empty window. From the
[documentation](http://pyqt.sourceforge.net/Docs/PyQt5/designer.html), the
**ui_imagedialog** is an imaginary file.
|
Passing thread to threaded object
Question: Quick question on the use of `QThread` in PyQt4 and Python 2.7. I am creating
a process inherited from `QObject`, and assigning this to a `Qthread` I have
created in a separate class (also inherited from `QObject`).
Is it safe to pass the `QThread` object to the process object, so that I can
call `thread.msleep(mseconds)` from within the process itself?
I want to be able to make the thread wait or sleep, but I have read that
time.sleep(seconds) is dodgy when used with PyQt multi-threading.
I did try to send a signal from the process object to a slot in the main
thread (attached to `thread.msleep(mseconds)` for that process object), but I
found that this failed to work; the process object continued executing until
complete, with the slot only being executed after this time. Even after
adjusting priorities, this continued to happen. This is unacceptable since I
want the process loop to run continuously.
Any other recommendations?
Answer: I eventually managed to alter my code to achieve the functionality that I
required in my question: namely the ability to make a thread wait or sleep for
a specified amount of time.
Firstly, my research seems to show that one of the main reasons subclassing
`QThread` became ill-advised in Qt was that a thread should not be able to
manage itself. Though there is no official documentation on my question, I can
only surmise that passing the thread object to the process object running on
it would also be ill-advised, because the thread would again be able to
control itself directly.
The solution I have found is to dispense with `msleep()` altogether. Qt
documentation on QThread recommends that `sleep()` and `wait()` functions are
avoided because they do not fit well with the event driven nature of Qt. They
recommend that `QTimer()` is used to call a function via a signal after it
times out, in place of `msleep()`. By default `QTimer()` is used to send a
repeating signal every time interval, but can also send a signal once using
`QTimer.singleShot()`. It is also stated in the documentation that it is safe
to call `QSleep()` from within a thread.
I only use a repeating `QTimer` to call a single slot `foo()` multiple times,
but to add a delay within `foo()`, `QTimer.singleShot()` could be used to call
a second function `moo()` after a set number of milliseconds.
EDIT: I have decided to include my threading code, which subclasses QObject
and QThread to perform a task on a thread in a continual loop every given time
interval. It is, as far as I can tell, fully functional, though could do with
a little work.
# -*- coding: utf-8 -*-
import sys
from PyQt4 import QtCore, QtGui
# Class to be assigned to a thread.
# This should be subclassed to provide new functionality.
class GenericLoop(QtCore.QObject):
def __init__(self):
super(GenericLoop, self).__init__()
# We use this signal to tell the main thread
# when this thread is finished.
finished_Sig = QtCore.pyqtSignal()
# Default timeout is 0, i.e. do work on thread after
# other events have been dealt with
__timeout = 0
__processTimer = None
__args = None
__kwargs = None
# We use this function to set the arguments used by run(),
# if we want to change them mid-execution
@QtCore.pyqtSlot(tuple, dict)
def changeArgs(self, args, kwargs):
self.__args = args
self.__kwargs = kwargs
# We can change the timeout used to make the thread run
# at given intervals. Note that the timing is not exact,
# since this is impossible with a real time operating system
@QtCore.pyqtSlot(int)
def setTimeout(self, mseconds):
self.__timeout = int(mseconds)
# Call either a singleShot QTimer (one execution),
# or a normal QTimer (repeated), to start the loop
@QtCore.pyqtSlot(bool, tuple, dict)
def startTimer(self, singleShot, args, kwargs):
self.__processTimer = QtCore.QTimer()
# We can't pass args and kwargs directly because QTimer.timeout
# emits a signal with allowing no contained variables
# so we copy args and kwargs to local variables instead
self.changeArgs(args, kwargs)
if singleShot:
self.__processTimer.singleShot(self.__timeout, self.callRun)
else:
self.__processTimer.timeout.connect(self.callRun)
self.__processTimer.start(self.__timeout)
# Call finish from within subclass using self.finish(), or
# from another thread using signals. finish() will stop the
# QTimer causing execution of the loop. The loop can be started again
# by calling startTimer() or stopTimer() from another thread
@QtCore.pyqtSlot()
def stopTimer(self):
if self.__processTimer.isActive():
self.__processTimer.stop()
else:
print "ERROR: stopTimer() has been called but no timer is running!"
# We call this to delete the thread.
@QtCore.pyqtSlot()
def deleteThread(self):
self.finished_Sig.emit()
# This calls run(), in order to enable the passing of
# command line arguments to the loop
@QtCore.pyqtSlot()
def callRun(self):
self.run(self.__args, self.__kwargs)
# run() can be called directly from another thread if required
@QtCore.pyqtSlot(tuple, dict)
def run(self, args, kwargs):
print "ERROR: run() has not been defined! Stopping thread..."
self.stopTimer()
# Class for creating threads
class GenericThread(QtCore.QObject):
# Private variables include the thread.
__sendArguments_Sig = QtCore.pyqtSignal(tuple, dict)
__startTimer_Sig = QtCore.pyqtSignal(int, tuple, dict)
__setTimeout_Sig = QtCore.pyqtSignal(int)
__obj = None
__finished_Sig = None
__thread = QtCore.QThread()
# Object to be threaded must be specified when
# creating a GenericThread object
def __init__(self, obj):
super(GenericThread, self).__init__()
self.__obj = obj
self.moreInit()
# Set up object on thread
def moreInit(self):
self.__thread = QtCore.QThread()
self.__obj.moveToThread(self.__thread)
# Allows thread to delete itself when done
self.__obj.finished_Sig.connect(self.__thread.deleteLater)
self.__sendArguments_Sig.connect(self.__obj.changeArgs)
self.__startTimer_Sig.connect(self.__obj.startTimer)
self.__setTimeout_Sig.connect(self.__obj.setTimeout)
self.__thread.start()
# Sets the QTimer timeout and does some checking
# to make sure that types are as they should be
def setTimeout(self, mseconds):
if mseconds >= 0 and type(mseconds) is type(int()):
self.__setTimeout_Sig.emit(mseconds)
elif mseconds < 0 and type(mseconds) is type(int()):
print "Error: timeout of below 0 ms specified."
else:
print "Error: timeout period is specified with a type other than int."
# Starts a function in the thread via signals, and can pass
# it arguments if required. Function executes until QTimer is stopped
def startLoop(self, *args, **kwargs):
if (self.__thread == None):
print "ERROR: Thread has been deleted!"
else:
self.__startTimer_Sig.emit(False, args, kwargs)
# Starts a function in the thread via signals, once
def startOnce(self, *args, **kwargs):
if (self.__thread == None):
print "ERROR: Thread has been deleted!"
else:
self.__startTimer_Sig.emit(True, args, kwargs)
# Calls a very simple GUI just to show that the program is responsive
class GUIBox(QtGui.QWidget):
def __init__(self):
super(GUIBox, self).__init__()
self.initUI()
def initUI(self):
self.resize(250, 150)
self.setWindowTitle('Threading!')
self.show()
# Subclass GenericLoop to reimplement run and such.
class SubClassedLoop(GenericLoop):
def __init__(self):
super(SubClassedLoop, self).__init__()
__i = 0
@QtCore.pyqtSlot(tuple, dict)
def run(self, args, kwargs):
if self.__i>=50:
self.stopTimer()
return
print self.__i, args
self.__i += 1
app = QtGui.QApplication(sys.argv)
ex = GUIBox()
# Create 3 worker objects to do the actual calculation
worker1 = SubClassedLoop()
worker2 = SubClassedLoop()
worker3 = SubClassedLoop()
# Create 3 thread managing objects to do the thread control
thread1 = GenericThread(worker1)
thread2 = GenericThread(worker2)
thread3 = GenericThread(worker3)
# Set the threads to execute as soon as there is no work to do
thread1.setTimeout(125)
thread2.setTimeout(125)
thread3.setTimeout(125)
# Start threads
thread1.startLoop(1)
thread2.startLoop(2)
thread3.startLoop(3)
# Quit the program when the GUI window is closed
sys.exit( app.exec_() )
|
Using owl:Class prefix with rdflib and xml serialization
Question: I would like to use the `owl:` prefix in the XML serialization of my RDF
ontology (using rdflib version 4.1.1); unfortunately I'm still getting the
serialization as `rdf:Description` tags. I have looked at the answer about
binding the namespace to the graph at [RDFLib: Namespace prefixes in XML
serialization](http://stackoverflow.com/questions/4427607/rdflib-namespace-
prefixes-in-xml-serialization) but this seems to only work when serializing
using the `ns` format rather than `xml` format.
Let's be more concrete. I'm attempting to get the following ontology (as taken
from [Introducing RDFS and OWL](http://www.linkeddatatools.com/introducing-
rdfs-owl)) in XML as follows:
<!-- OWL Class Definition - Plant Type -->
<owl:Class rdf:about="http://www.linkeddatatools.com/plants#planttype">
<rdfs:label>The plant type</rdfs:label>
<rdfs:comment>The class of all plant types.</rdfs:comment>
</owl:Class>
Here is the python code for constructing such a thing, using `rdflib`:
from rdflib.namespace import OWL, RDF, RDFS
from rdflib import Graph, Literal, Namespace, URIRef
# Construct the linked data tools namespace
LDT = Namespace("http://www.linkeddatatools.com/plants#")
# Create the graph
graph = Graph()
# Create the node to add to the Graph
Plant = URIRef(LDT["planttype"])
# Add the OWL data to the graph
graph.add((Plant, RDF.type, OWL.Class))
graph.add((Plant, RDFS.subClassOf, OWL.Thing))
graph.add((Plant, RDFS.label, Literal("The plant type")))
graph.add((Plant, RDFS.comment, Literal("The class of all plant types")))
# Bind the OWL and LDT name spaces
graph.bind("owl", OWL)
graph.bind("ldt", LDT)
print graph.serialize(format='xml')
Sadly, even with those bind statements, the following XML is printed:
<?xml version="1.0" encoding="UTF-8"?>
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
>
<rdf:Description rdf:about="http://www.linkeddatatools.com/plants#planttype">
<rdfs:subClassOf rdf:resource="http://www.w3.org/2002/07/owl#Thing"/>
<rdfs:label>The plant type</rdfs:label>
<rdfs:comment>The class of all plant types</rdfs:comment>
<rdf:type rdf:resource="http://www.w3.org/2002/07/owl#Class"/>
</rdf:Description>
</rdf:RDF>
Granted, this is still an Ontology, and usable - but since we have various
editors, the much more compact and readable first version using the `owl`
prefix would be far preferable. Is it possible to do this in `rdflib` without
overriding the serialization method?
**Update**
In response to the comments, I'll rephrase my "bonus question" as simple
clarification to my question at large.
**Not a Bonus Question** The topic here involves the construction of the OWL
namespace formatted ontology which is a shorthand for the more verbose RDF/XML
specification. The issue here is larger though than the simple declaration of
a namespace prefix for shorthand for only Classes or Properties, there are
many shorthand notations that have to be dealt with in code; for example
`owl:Ontology` descriptions should be added as good form to this notation. I
am hoping that rdflib has support for the complete specification of the
notation- rather than have to roll my own serialization.
Answer: Instead of using the `xml` format, you need to use the `pretty-xml` format.
It's listed in the documentation, [Plugin
serializers](https://rdflib.readthedocs.org/en/4.1.0/plugin_serializers.html).
That will give you the type of output that you're looking for. That is, you'd
use a line like the following in order to use the
[PrettyXMLSerializer](http://www.rdflib.net/rdflib-2.4.0/html/public/rdflib.syntax.serializers.PrettyXMLSerializer.PrettyXMLSerializer-
class.html):
print graph.serialize(format='pretty-xml')
To address the "bonus question", you can add a line like the following to
create the ontology header, and then serializing with `pretty-xml` will give
you the following output.
graph.add((URIRef('http://stackoverflow.com/q/24017320/1281433/ontology.owl'), RDF.type, OWL.Ontology ))
<?xml version="1.0" encoding="utf-8"?>
<rdf:RDF
xmlns:owl="http://www.w3.org/2002/07/owl#"
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
>
<owl:Ontology rdf:about="http://stackoverflow.com/q/24017320/1281433/ontology.owl"/>
<owl:Class rdf:about="http://www.linkeddatatools.com/plants#planttype">
<rdfs:comment>The class of all plant types</rdfs:comment>
<rdfs:subClassOf rdf:resource="http://www.w3.org/2002/07/owl#Thing"/>
<rdfs:label>The plant type</rdfs:label>
</owl:Class>
</rdf:RDF>
Adding the `x rdf:type owl:Ontology` triple isn't a very OWL-centric way of
declaring the ontology though. It sounds like you're looking for something
more like Jena's OntModel interface (which is just a convenience layer over
Jena's RDF-centric Model), or the OWLAPI, but for RDFLib. I don't know whether
such a thing exists (I'm not an RDFlib user), but you might have a look at:
* [RDFLib/OWL-RL](https://github.com/RDFLib/OWL-RL): It looks like a reasoner, but it might have some of the methods that you need.
* [Inspecting an ontology with RDFLib](http://www.michelepasin.org/blog/2011/07/18/inspecting-an-ontology-with-rdflib/): a blog article with links to source that might do some of what you want.
* [Is there a Python library to handle OWL?](http://stackoverflow.com/q/1719812/1281433): A Stack Overflow question (now off-topic, because library/tool requests are off-topic, but it's an old question) where the accepted answer points out that rdflib is RDF-centric, not OWL-centric, but some of the other answers might be useful, particular [this one](http://stackoverflow.com/a/8379891/1281433), although most of those were outdated, even in 2011.
|
LED fade in python - implementing multithreading
Question: I'm trying to build a program that controls an RGB LED through a RaspberryPi.
I was able to build a simple fade program in python using [pi-
blaster](https://github.com/sarfata/pi-blaster/), which works fine but doesn't
let me do what I want.
Here's my code:
import time
import sys
import os
blue = 21
green = 23
red = 22
def fade(color, direction, step):
if direction == 'up':
for i in range(0, 100, step):
f=(i/float(100))
os.system('echo "%d=%f" > /dev/pi-blaster' % (color, f))
return fade(color, 'down', step)
else:
step=-step
for i in range (100, 0, step):
f=(i/float(100))
os.system('echo "%d=%f" > /dev/pi-blaster' % (color, f))
return fade(color, 'up', step)
input = raw_input("Choose a color (r, g, b): ")
if input == 'r':
fade(red, 'up', 1)
if input == 'g':
fade(green, 'up', 1)
if input == 'b':
fade(blue, 'up', 1)
The problem is that I want to be able to control the fade through an external
script / program.
My idea is to have a script which is always listening for user input, so when
I type "red" it stops the ongoing fade and starts a new red one, by calling
the function I posted before.
I also want to be able to change the speed of the loop but this is already
implemented into the "fade" function.
I don't really understand how I could do this. I've read some things on here
and I think I may have to use the Threading functions, but I don't really
understand how those could work for my project.
Thanks in advance for your help and sorry for my English which is not very
good :)
EDIT:
I solved it using a loop checking continuously for keyboard inputs which then
calls the fade function using multiprocessing.
I can now kill the fade process using processName.terminate()
Answer: to get much better performance (and as a clarification to the first answer) it
is much better to write using python - but you must put a new line after each
write with a '\n'
Otherwise the code @daveydave400 gave is spot on
I'm doing something like this:
f = open('/dev/pi-blaster', 'w')
f.write('0=120\n')
#or
f.write('0=%s\n'%amount)
my actual code is in a function - in case you want to use that:
def changer(pin, amount):
f = open('/dev/pi-blaster', 'w')
f.write('%d=%s\n'%(pin, str(amount)))
if doing for loops using the the system command method you might find that
python stops listening for keyboard input intermittently. This was certainly
happening for me. I found that keyboardinterrupt was very hard to achieve with
ctrl-c and had to repeatedly hit those keys to get the program to halt. Now
i'm writing with python i'm not getting that issue.
|
Find edges in a cycle networkx python
Question: I would like to make an algorithm to find if an edge belongs to a cycle, in an
undirected graph, using networkx in Python. I am thinking to use `cycle_basis`
and get all the cycles in the graph. My problem is that `cycle_basis` returns
a list of nodes. How can I convert them to edges?
Answer: You can construct the edges from the cycle by connecting adjacent nodes.
In [1]: import networkx as nx
In [2]: G = nx.Graph()
In [3]: G.add_cycle([1,2,3,4])
In [4]: G.add_cycle([10,20,30])
In [5]: basis = nx.cycle_basis(G)
In [6]: basis
Out[6]: [[2, 3, 4, 1], [20, 30, 10]]
In [7]: edges = [zip(nodes,(nodes[1:]+nodes[:1])) for nodes in basis]
In [8]: edges
Out[8]: [[(2, 3), (3, 4), (4, 1), (1, 2)], [(20, 30), (30, 10), (10, 20)]]
|
Clustering 500,000 geospatial points in python
Question: I'm currently faced with the problem of finding a way to cluster around
500,000 latitude/longitude pairs in python. So far I've tried computing a
distance matrix with numpy (to pass into the scikit-learn DBSCAN) but with
such a large input it quickly spits out a Memory Error.
The points are stored in tuples containing the latitude, longitude, and the
data value at that point.
In short, what is the most efficient way to spatially cluster a large number
of latitude/longitude pairs in python? For this application, I'm willing to
sacrifice some accuracy in the name of speed.
Edit: The number of clusters for the algorithm to find is unknown ahead of
time.
Answer: I don't have your data so I just generated 500k random numbers into three
columns.
import numpy as np
import matplotlib.pyplot as plt
from scipy.cluster.vq import kmeans2, whiten
arr = np.random.randn(500000*3).reshape((500000, 3))
x, y = kmeans2(whiten(arr), 7, iter = 20) #<--- I randomly picked 7 clusters
plt.scatter(arr[:,0], arr[:,1], c=y, alpha=0.33333);
out[1]:
I timed this and it took 1.96 seconds to run this Kmeans2 so I don't think it
has to do with the size of your data. Put your data in a 500000 x 3 numpy
array and try kmeans2.
|
When I run my fabfile, I am being asked for password although I specified a key. Why?
Question: Good Day,
I have a python script which runs a fabfile. My issue is that I am asked for a
password whenever I run the fabfile from my script. However, the login works
fine with the specified key when I run the fabfile manually from the command
line even though I am using the same fab parameters. Here is the contents of
my fabfile:
[root@ip-10-10-20-82 bakery]# cat fabfile.py
from fabric.api import run
def deploy():
run('wget -P /tmp https://s3.amazonaws.com/LinuxBakery/httpd-2.2.26-1.1.amzn1.x86_64.rpm')
run('sudo yum localinstall /tmp/httpd-2.2.26-1.1.amzn1.x86_64.rpm')
Here is the syntax I use on the command line that works successfully:
fab -u ec2-user -i id_rsa -H 10.10.15.185 deploy
Here is the bit of python code which for some reason is prompting for a
password instead of using the key:
import subprocess
subprocess.call(['fab', '-f', '/home/myhome/scripts/bakery/fabfile.py', '-u ec2-user', '-i', '/home/myhome/scripts/bakery/id_rsa', '-H', bakery_internalip, 'deploy'])
Here is what happens when I run it:
[10.10.15.185] Executing task 'deploy'
[10.10.15.185] run: wget -P /tmp https://s3.amazonaws.com/LinuxBakery/httpd-2.2.26-1.1.amzn1.x86_64.rpm
[10.10.15.185] Login password for ' ec2-user':
Answer: I was being asked for a password even though I had specified a key because
there was an extra space between the "u" and "ec2-user". Here is the snippet
before:
'-u ec2-user'
And here it is after:
'-uec2-user'
The extra space meant that fab was trying to authenticate with " ec2-user"
instead of "ec2-user".
|
Handling an image download popup
Question: I'm trying to download an image using Python's Mechanize, and that's an easy
thing to do with urlretrieve, however this image's 'src' attribute holds a url
which initiates a download popup. There doesn't seem to be a url that points
to the image.
I'm using Python Mechanize, but my research tells me that there's no way to
handle the pop up in Mechanize, and I would have to use something like
Selenium. Is this the case?
Answer: Yes Selenium seems to be the case for this. The following code shows how to
deal with pop-up's.
from selenium import webdriver
from selenium.webdriver.common.alert import Alert
driver = webdriver.Firefox()
driver.get(url)
try:
alert = self.driver.switch_to_alert()
# do something with alert, like download the content
alert.dismiss()
except:
pass
|
Starting script using pyinotofy as daemon process
Question: I have a number of questions regarding starting a script using pyinotify as a
daemon.
I have some code like this:
#!/usr/bin/env python
import sys
import pyinotify
import shutil
import glob
PACKAGES_DIR = '/var/my-packages'
PACKAGES_TEMP_DIR = '/var/www-data/package_temp'
wm = pyinotify.WatchManager()
mask = pyinotify.IN_MOVED_TO
class ProcessPackages(pyinotify.ProcessEvent):
def process_IN_MOVED_TO(self, event):
for directory in glob.glob(PACKAGES_TEMP_DIR + '/*'):
shutil.move(directory, PACKAGES_DIR)
handler = ProcessPackages()
notifier = pyinotify.Notifier(wm, handler)
wdd = wm.add_watch(PACKAGES_TEMP_DIR, mask)
try:
notifier.loop(daemonize=True, pid_file='/tmp/packages.pid', stdout='/tmp/stdout.txt')
except pyinotify.NotifierError, err:
print >> sys.stderr, err
My question now is if I set to the daemonize parameter to True does this mean
that the whole script is run as daemon or is it just pyinotify?
If it is only pyinotify how would I go about running this entire script as a
daemon process?
If I run the script as daemon is it really necessary to make pyinotify a
daemon as well?
My last question is if pyinotify is daemonized would I definitely need a
callback? In my case I just want the script to run forever and being killed
only on system reboot/restart.
The script should also run like any standard startup script without manual
intervention.
FYI,
I am running an Ubuntu 12.04 server.
Thanks in advance, nav
Answer: I run an ipynotify-dependent process as a system service (which is what you
want, by the sound of things), using Upstart - also on Ubuntu 12.04.
Personally, I didn't modify the python script **at all**. I just made sure it
ran fine at the terminal, then created an upstart config file like so:
_/etc/init/myservice.conf_ :
description "MyService"
author "My Name"
start on runlevel [2345]
stop on runlevel [!2345]
# Automatically restart process if crashed
#respawn
exec su myuser -c "/usr/bin/python /path/to/myscript.py > /tmp/myscript.log 2>&1"
When your init file is in place, you'll want to try something like `sudo start
myservice`, then inspect _/tmp/myscript.log_ for any errors.
HTH!
|
How to extract all columns but one from an array (or matrix) in python?
Question: Given a numpy 2d array (or a matrix), I would like to extract all the columns
but the i-th.
E. g. from
1 2 3 4
2 4 6 8
3 6 9 12
I would like to have, e.g.
1 2 3
2 4 6
3 6 9
or
1 2 4
2 4 8
3 6 12
I cannot find a pythonic way to do this. I now that you can extract given
columns by simply
a[:,n]
or
a[:,[n,n+1,n+5]]
But what about extracting all of them but one?
Answer: Take a look at numpy's [advanced
slicing](http://docs.scipy.org/doc/numpy/reference/arrays.indexing.html#boolean)
>>> import numpy as np
>>> a = np.array([[1,2,3,4], [2,4,6,8], [3,6,9,12]])
>>> a[:,np.array([True, True, False, True])]
array([[ 1, 2, 4],
[ 2, 4, 8],
[ 3, 6, 12]])
|
Debug django tests
Question: I see that [TestCase](https://docs.python.org/3/library/unittest.html) has a
method
[Debug()](https://docs.python.org/3/library/unittest.html#unittest.TestCase.debug),
but I can't find any example on how to implement it. As far as I've tried,
nothing works.
Can anyone provide some code as to how to use it?
Answer: ## debugunit.py
from unittest import TestCase
class MyTest(TestCase):
def test1(self):
print 'before'
self.assertEquals(2+2, 5)
print 'after'
## run
> python -i debugunit.py
To run a test interactively, create a `TestCase` instance, giving it the test
name as a parameter. To run it, call the resulting object.
>>> print MyTest('test1')()
before
None
The "2+2!=5" exception is consumed by the unittest machinery. To get the set
to run (with `setUp` and `tearDown`, etc), run the `debug()` method:
>>> MyTest('test1').debug()
before
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python2.7/unittest/case.py", line 400, in debug
getattr(self, self._testMethodName)()
File "debugunit.py", line 6, in test1
self.assertEquals(2+2, 5)
File "/usr/lib/python2.7/unittest/case.py", line 515, in assertEqual
assertion_func(first, second, msg=msg)
File "/usr/lib/python2.7/unittest/case.py", line 508, in _baseAssertEqual
raise self.failureException(msg)
AssertionError: 4 != 5
|
python throwing an error HTTP 401 while accessing https://stream.twitter.com/1.1/statuses/filter.json
Question: This is the Code I am running to get the stream of tweets using Streaming API
by accessing the stream.twitter url mentioned in title. but it is throwing an
error (HTTP error 401) In the code I am trying to track multiple terms
import time
import pycurl
import urllib
import json
import oauth2
API_ENDPOINT_URL = 'https://stream.twitter.com/1.1/statuses/filter.json'
USER_AGENT = 'TwitterStream 1.0'
OAUTH_KEYS = {'consumer_key': 'ABC',
'consumer_secret': 'ABC',
'access_token_key': 'ABC',
'access_token_secret': 'ABC'}
POST_PARAMS = {'include_entities': 0,
'stall_warning': 'true',
'track': 'iphone,ipad,ipod'}
class TwitterStream():
def __init__(self, timeout=False):
#self.oauth_token = Token(key=OAUTH_KEYS['access_token_key'], secret=OAUTH_KEYS['access_token_secret'])
self.oauth_consumer = oauth2.Consumer(key=OAUTH_KEYS['consumer_key'], secret=OAUTH_KEYS['consumer_secret'])
self.oauth_token = oauth2.Token(key=OAUTH_KEYS['access_token_key'], secret=OAUTH_KEYS['access_token_secret'])
self.conn = None #pycurl.Curl()
self.buffer = ''
self.timeout = timeout
self.setup_connection()
def setup_connection(self):
""" Create persistant HTTP connection to Streaming API endpoint using cURL.
"""
if self.conn:
self.conn.close()
self.buffer = ''
self.conn = pycurl.Curl()
# Restart connection if less than 1 byte/s is received during "timeout" seconds
if isinstance(self.timeout, int):
self.conn.setopt(pycurl.LOW_SPEED_LIMIT, 1)
self.conn.setopt(pycurl.LOW_SPEED_TIME, self.timeout)
self.conn.setopt(pycurl.URL, API_ENDPOINT_URL)
self.conn.setopt(pycurl.USERAGENT, USER_AGENT)
# Using gzip is optional but saves us bandwidth.
self.conn.setopt(pycurl.ENCODING, 'deflate, gzip')
self.conn.setopt(pycurl.POST, 1)
self.conn.setopt(pycurl.POSTFIELDS, urllib.urlencode(POST_PARAMS))
self.conn.setopt(pycurl.HTTPHEADER, ['Host: stream.twitter.com',
'Authorization: %s' % self.get_oauth_header()])
# self.handle_tweet is the method that are called when new tweets arrive
self.conn.setopt(pycurl.WRITEFUNCTION, self.handle_tweet)
def get_oauth_header(self):
""" Create and return OAuth header.
"""
params = {'oauth2_version': '1.0',
'oauth2_nonce': oauth2.generate_nonce(),
'oauth2_timestamp': int(time.time())}
req = oauth2.Request(method='POST', parameters=params, url='%s?%s' % (API_ENDPOINT_URL,
urllib.urlencode(POST_PARAMS)))
req.sign_request(oauth2.SignatureMethod_HMAC_SHA1(), self.oauth_consumer, self.oauth_token)
return req.to_header()['Authorization'].encode('utf-8')
def start(self):
""" Start listening to Streaming endpoint.
Handle exceptions according to Twitter's recommendations.
"""
backoff_network_error = 0.25
backoff_http_error = 5
backoff_rate_limit = 60
while True:
self.setup_connection()
try:
self.conn.perform()
except:
# Network error, use linear back off up to 16 seconds
print 'Network error: %s' % self.conn.errstr()
print 'Waiting %s seconds before trying again' % backoff_network_error
time.sleep(backoff_network_error)
backoff_network_error = min(backoff_network_error + 1, 16)
continue
# HTTP Error
sc = self.conn.getinfo(pycurl.HTTP_CODE)
if sc == 420:
# Rate limit, use exponential back off starting with 1 minute and double each attempt
print 'Rate limit, waiting %s seconds' % backoff_rate_limit
time.sleep(backoff_rate_limit)
backoff_rate_limit *= 2
else:
# HTTP error, use exponential back off up to 320 seconds
print 'HTTP error %s, %s' % (sc, self.conn.errstr())
print 'Waiting %s seconds' % backoff_http_error
time.sleep(backoff_http_error)
backoff_http_error = min(backoff_http_error * 2, 320)
def handle_tweet(self, data):
""" This method is called when data is received through Streaming endpoint.
"""
self.buffer += data
if data.endswith('\r\n') and self.buffer.strip():
# complete message received
message = json.loads(self.buffer)
self.buffer = ''
msg = ''
if message.get('limit'):
print 'Rate limiting caused us to miss %s tweets' % (message['limit'].get('track'))
elif message.get('disconnect'):
raise Exception('Got disconnect: %s' % message['disconnect'].get('reason'))
elif message.get('warning'):
print 'Got warning: %s' % message['warning'].get('message')
else:
print 'Got tweet with text: %s' % message.get('text')
if __name__ == '__main__':
ts = TwitterStream()
ts.setup_connection()
ts.start()
Please help me to resolve it.
Answer: You could try updating your clock.
sudo ntpdate ntp.ubuntu.com
From: <http://lembra.wordpress.com/2012/03/08/twitter-stream-
mysterious-401unauthorized-status-with-oauth-and-clock-issue/>
|
Hidden (missing) library dependency, when linking with cl.exe
Question: I've just been exposed to a large non-trivial CMake/Eclipse based C++ project.
One of the build targets is Windows/nmake based. In the final step of building
an executable, the linker throws LNK1104: cannot open file 'python27.lib'.
This is correct, because Python 2.7 hasn't been installed.
Problem is, I cannot find any references to this library in cl.exe's command
line. Also a grep on the whole project directory (including eclipses .metadata
directory) won't find anything plausible. Deleting all the cmake generated
build stuff didn't help too.
The real question is, if MSVC-based libraries (import or static ones) have any
mechanism to request additional libraries during the link step implicitely.
There are a few pre-compiled ones in the mentioned project. I simply need the
vocabulary, where to begin a more qualified search regarding the error cause.
Answer: I found the answer here:
[Puzzling dependency of Boost.Python 1.54 (debug build) to Python27.lib on
Windows](http://stackoverflow.com/questions/19716859/puzzling-dependency-of-
boost-python-1-54-debug-build-to-python27-lib-on-window)
Basically, the culprit is a `#pragma comment()` directive inside the boost
libraries.
|
flask-restless with mod_wsgi can't connect to MySQL server
Question: I am trying to run a flask-restless app in apache using mod_wsgi. This works
fine with the development server. I have read everything I can find and none
of the answers I have seen seem to work for me. The app handles non-database
requests properly but gives the following error when I try to access a url
that requires a database access:
`OperationalError: (OperationalError) (2003, "Can't connect to MySQL server on
'localhost' ([Errno 13] Permission denied)") None None`
I have whittled down to basically the flask-restless quick-start with my
`config` and my flask-sqlalchemy models imported (`from flask import models`).
Here is my python code:
import flask
import flask.ext.sqlalchemy
import flask.ext.restless
import sys
sys.path.insert(0, '/proper/path/to/application')
application = flask.Flask(__name__, static_url_path = "")
application.debug=True
application.config.from_object('config')
db = flask.ext.sqlalchemy.SQLAlchemy(application)
from app import models
# Create the Flask-Restless API manager.
manager = flask.ext.restless.APIManager(application, flask_sqlalchemy_db=db)
# Create API endpoints, which will be available at /api/<tablename> by
# default. Allowed HTTP methods can be specified as well.
manager.create_api(models.Asset, methods=['GET'])
# start the flask loop
if __name__ == '__main__':
application.run()
I assume that mod_wsgi isn't having a problem finding the `config` file which
contains the database access details since I don't get an error when reading
the config and I also don't get an error on `from app import models`.
My research so far has led me to believe that this has something to do with
the sql-alchemy db connection existing in the wrong scope or context and
possibly complicated by the flask-restless API manager. I can't seem to wrap
my head around it.
Answer: Your code under Apache/mod_wsgi will run as a special Apache user. That user
likely doesn't have the privileges required to connect to the database.
Even though it says 'localhost' and you think that may imply a normal socket
connection, some database clients will see 'localhost' and will automatically
instead try and use the UNIX socket for the database. It may not have access
to that UNIX socket connection.
Alternatively, when going through a UNIX socket connection it is trying to
validate whether the Apache user than has access, but if the database hasn't
been setup to allow the Apache user access, it may then fail.
Consider using daemon mode of mod_wsgi and configure daemon mode to run as a
different user to the Apache user and one you know has access to the database.
|
Saving Image in a temporary file in django
Question: I am very new in python and django.I have developed a project using django.
Here all the images are watermarked.I have watermarked all the images using
the following code...
from PIL import Image
def image_watermark(request,image_id):
photo = Photo.objects.get(pk=image_id)
watermark = Image.open('{0}/{1}'.format(settings.MEDIA_ROOT,'wmark.png'))
img = Image.open(photo.photo.file)
img.paste(watermark,(img.size[0]-watermark.size[0],img.size[1]- watermark.size[1]),watermark)
img.save('{0}/{1}'.format(settings.MEDIA_ROOT,photo.photo.name), quality=80)
wrapper = FileWrapper(open(photo.photo.url, 'rb'))
response = StreamingHttpResponse(wrapper, 'image/jpeg')
response['Content-Length'] = os.path.getsize(photo.photo.url)
response['Content-Disposition'] = 'attachment; filename=photo.jpg'
return response
all of my images are watermarked now.But the problem is,as a user ,if i
download these images,i found that the downloaded images are also
watermarked,but i want to download the actual image,not the watermarked
image,how can i solve the problem?
Answer: You need to store the watermarked image into a different file. First you need
to create another column to store the Watermarked image.
class Photo(models.Model):
...
watermarked_photo = ImageField()
Then when you save the watermarked image into that column.
from PIL import Image
def image_watermark(request,image_id):
photo = Photo.objects.get(pk=image_id)
# Only need to watermark when there's no watermark
if not photo.watermarked_photo.name:
photo.watermarked_photo.name = 'watermarked_' + photo.photo.name
watermark = Image.open('{0}/{1}'.format(settings.MEDIA_ROOT,'wmark.png'))
img = Image.open(photo.photo.file)
img.paste(watermark,(img.size[0]-watermark.size[0],img.size[1]- watermark.size[1]),watermark)
img.save('{0}/{1}'.format(settings.MEDIA_ROOT, photo.watermarked_photo.name), quality=80)
photo.save()
wrapper = FileWrapper(open(photo.watermarked_photo.url, 'rb'))
response = StreamingHttpResponse(wrapper, 'image/jpeg')
response['Content-Disposition'] = 'attachment; filename=photo.jpg'
return response
My Django skill is a bit rusty, so this code might not work without some
modification. But the idea should be solid.
If you only want to use a temp file, then try this
from PIL import Image
import tempfile
def image_watermark(request,image_id):
photo = Photo.objects.get(pk=image_id)
watermark = Image.open('{0}/{1}'.format(settings.MEDIA_ROOT,'wmark.png'))
img = Image.open(photo.photo.file)
img.paste(watermark,(img.size[0]-watermark.size[0],img.size[1]- watermark.size[1]),watermark)
tmpfile = tempfile.TemporaryFile()
img.save(tmpfile, img.format, quality=80)
tmpfile.seek(0)
wrapper = FileWrapper(tmpfile)
response = StreamingHttpResponse(wrapper, 'image/jpeg')
response['Content-Disposition'] = 'attachment; filename=photo.jpg'
return response
|
How to read from QTextedit in python?
Question: I created the GUI using QTDesigner and save the file as .ui extension. Then
convert the file to .py file using the following code
pyuic4 -x test.ui -o test.py
Now I want to integrate my project code to this test.py file. Since I am new
to pyqt4, I dont know how to read text from text edit and save to file and
viceversa. Following is my code.
from PyQt4 import QtCore, QtGui
from final_ar_gui import *
try:
_fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
_fromUtf8 = lambda s: s
class Ui_AnaphoraResolution(object):
def setupUi(self, AnaphoraResolution):
AnaphoraResolution.setObjectName(_fromUtf8("AnaphoraResolution"))
AnaphoraResolution.resize(608, 620)
self.textEdit = QtGui.QTextEdit(AnaphoraResolution)
self.textEdit.setGeometry(QtCore.QRect(0, 110, 271, 341))
self.textEdit.setObjectName(_fromUtf8("textEdit"))
self.textEdit_2 = QtGui.QTextEdit(AnaphoraResolution)
self.textEdit_2.setGeometry(QtCore.QRect(310, 110, 271, 341))
self.textEdit_2.setObjectName(_fromUtf8("textEdit_2"))
self.pushButton = QtGui.QPushButton(AnaphoraResolution)
self.pushButton.setGeometry(QtCore.QRect(40, 470, 91, 27))
self.pushButton.setObjectName(_fromUtf8("pushButton"))
self.pushButton_2 = QtGui.QPushButton(AnaphoraResolution)
self.pushButton_2.setGeometry(QtCore.QRect(170, 470, 171, 27))
self.pushButton_2.setObjectName(_fromUtf8("pushButton_2"))
self.pushButton_3 = QtGui.QPushButton(AnaphoraResolution)
self.pushButton_3.setGeometry(QtCore.QRect(370, 470, 81, 27))
self.pushButton_3.setObjectName(_fromUtf8("pushButton_3"))
self.pushButton_4 = QtGui.QPushButton(AnaphoraResolution)
self.pushButton_4.setGeometry(QtCore.QRect(480, 470, 98, 27))
self.pushButton_4.setObjectName(_fromUtf8("pushButton_4"))
self.label = QtGui.QLabel(AnaphoraResolution)
self.label.setGeometry(QtCore.QRect(180, 30, 241, 20))
self.label.setObjectName(_fromUtf8("label"))
self.retranslateUi(AnaphoraResolution)
self.connectActions()
QtCore.QMetaObject.connectSlotsByName(AnaphoraResolution)
def retranslateUi(self, AnaphoraResolution):
AnaphoraResolution.setWindowTitle(QtGui.QApplication.translate("AnaphoraResolution", "Dialog", None, QtGui.QApplication.UnicodeUTF8))
self.pushButton.setText(QtGui.QApplication.translate("AnaphoraResolution", "Enter", None, QtGui.QApplication.UnicodeUTF8))
self.pushButton_2.setText(QtGui.QApplication.translate("AnaphoraResolution", "Pronominal Resolution", None, QtGui.QApplication.UnicodeUTF8))
self.pushButton_3.setText(QtGui.QApplication.translate("AnaphoraResolution", "Clear", None, QtGui.QApplication.UnicodeUTF8))
self.pushButton_4.setText(QtGui.QApplication.translate("AnaphoraResolution", "Quit", None, QtGui.QApplication.UnicodeUTF8))
self.label.setText(QtGui.QApplication.translate("AnaphoraResolution", "Anaphora Resolution in Malayalam", None, QtGui.QApplication.UnicodeUTF8))
def connectActions(self):
self.pushButton.clicked.connect(self.ent)
def ent(self):
%Dont know what code to write
if __name__ == "__main__":
import sys
app = QtGui.QApplication(sys.argv)
AnaphoraResolution = QtGui.QDialog()
ui = Ui_AnaphoraResolution()
ui.setupUi(AnaphoraResolution)
AnaphoraResolution.show()
sys.exit(app.exec_())
When i click enter (push button) the input in the textEdit is read and save
into a file named input.txt. When i click quit (pushbutton) the output in the
outfile.txt is read and write into textEdit_2 . How to solve this ?
Answer: If all you need is the displayed text in your QTextEdit widget, you can access
that by using the
[`toPlainText()`](http://pyqt.sourceforge.net/Docs/PyQt4/qtextedit.html#toPlainText)
method on the widget you need the text from.
Example:
mytext = self.textEdit.toPlainText()
At this point, you can do whatever you want with `mytext`. You can write it to
a file, you can manipulated it, etc.
If you need to (re)populate your `QTextEdit` with the modified value of
`mytext`, you can do that by using
[`setPlainText`](http://pyqt.sourceforge.net/Docs/PyQt4/qtextedit.html#setPlainText)
self.textEdit.setPlainText(mytext)
To write the string to a file, you'll do something like this:
with open('somefile.txt', 'a') as f:
f.write(mytext)
This will append `mytext` to `somefile.txt`
|
Attribute error in python while trying to sign in
Question: I am using python (with selenium webdriver) to sign into yahoo.
Below is the code:
import unittest
from selenium import webdriver
from selenium.common.exceptions import NoSuchElementException
#Set Selenium firefox browser object
browser = webdriver.Firefox()
#Navigate to desired page
browser.get( 'https://www.yahoo.com/' )
try:
element = browser.find_element_by_title( 'Sign In' )
except NoSuchElementException:
self.fail( "found: %s" % 'Sign In' )
Below is the error I see:
element = browser.find_element_by_title( 'Sign In' )
AttributeError: 'WebDriver' object has no attribute 'find_element_by_title'
Any suggestions how to fix this error?
Answer: Use [`find_element_by_link_text()`](http://selenium-
python.readthedocs.org/en/latest/api.html#selenium.webdriver.remote.webelement.WebElement.find_element_by_link_text)
instead:
element = browser.find_element_by_link_text('Sign In')
Demo:
>>> from selenium import webdriver
>>> browser = webdriver.Firefox()
>>> browser.get('https://www.yahoo.com/')
>>> element = browser.find_element_by_link_text('Sign In')
>>> element
<selenium.webdriver.remote.webelement.WebElement object at 0x1087fc5d0>
|
python write files and maintain folder structure
Question: I'm working on a script that will read files from one location, manipulate the
data, and then write the output to a different location. At the command line
the user will use a -p to specify a top-level folder and then the script will
recurse through there and find all the files. I'm doing this using glob right
now and the reading of the file is fine.
But I also want the user to specify an output folder to write the files into
and I want to maintain the folder structure of the input path.
for eachFile in glob(args.path + "/*/*.json"): <- this seems dangerous. Better way?
# do something to the json file
# output the modified data to its new home
#outfile = os.path.join(args.output, os.path.dirname(eachFile), eachFile) <- doesn't work
outfile = os.path.join(args.putout, os.path.dirname(eachFile)[1:], eachFile)
That last line is the best I've done but it has the problem of assuming this
is being run on a posix machine when it strips off the "/" at the front of the
directory. Also, let's say I pass in an input path of ~/Documents/2014 and an
output of /tmp. The files will be written to
/tmp/Users/myusername/Documents/2014/blah/whatever.json.
This seems like a fairly common use case so I'm surprised that I haven't found
someone else that needed to do this or a simple module that does it easily.
Any suggestions?
Answer: Here is a script that does close to what you need. The key thing here, is
instead of glob, you needed os.walk because you want to drill down through the
directory structure. You'll need to add sanity checks, but it's a good start.
# Recurse and process files.
import os
import sys
from fnmatch import fnmatch
import shutil
def process(src_dir, dst_dir, pattern='*'):
"""Iterate through src_dir, processing all files that match pattern and
store them, including their parent directories in dst_dir.
"""
assert src_dir != dst_dir, 'Source and destination dir must differ.'
for dirpath, dirnames, filenames in os.walk(src_dir):
# Filter out files that match pattern only.
filenames = filter(lambda fname: fnmatch(fname, pattern), filenames)
if filenames:
dir_ = os.path.join(dst_dir, dirpath)
os.makedirs(dir_)
for fname in filenames:
in_fname = os.path.join(dirpath, fname)
out_fname = os.path.join(dir_, fname)
# At this point, the destination directory is created and you
# have a valid input / output filename, so you'd call your
# function to process these files. I just copy them :D
shutil.copyfile(in_fname, out_fname)
if __name__ == '__main__':
process(sys.argv[1], sys.argv[2], '*.txt')
|
Running multiple stored procedures using pypyodbc giving incomplete results
Question: I'm running a relatively simple python script that is meant to read a text
file that has a series of stored procedures - one per line. The script should
run the stored procedure on the first line, move to the second line, run the
stored procedure on the second line, etc etc. Running these stored procedures
should populate a particular table.
So my problem is that these procedures aren't populating the table with all of
the results that they should be. For example, if my file looks like
exec myproc 'data1';
exec myproc 'data2';
Where myproc 'data1' should populate this other table with about ~100 records,
and myproc 'data2' should populate this other table with an additional ~50
records. Instead, I end up with about 9 results total - 5 from the first proc,
4 from the second.
I know the procedures work, because if I run the same sql file (with the
procs) through OSQL and I get the correct ~150 records in the other table, so
obviously it's something to do with my script.
Here's the code I'm running to do this:
import pypyodbc
conn = pypyodbc.connect(CONN_STR.format("{SQL Server}",server,database,user,password))
conn.autoCommit = True
procsFile = openFile('otherfile.txt','r+')
#loop through each proc (line) in the file
for proc in procsFile:
#run the procedure
curs = conn.cursor()
curs.execute(proc)
#commit results
conn.commit()
curs.close();
conn.close();
procsFile.close();
I'm thinking this has something to do with the procedures not committing...or
something?? Frankly I don't really understand why only 5/100 records would be
committed.
I dont know. any help or advice would be much appreciated.
Answer: There a couple things to check. One is that your data1 is actually a string
'data1', or if you want the value of data1? If you want the string 'data1',
then you will have to add quotes around it. So your string to execute would
look like this:
exec_string = 'exec my_proc \'data1\';'
* * *
In your case you turn ON auto-commit and also you manually commit for the
entire connection.
I would comment out the auto-commit line:
#conn.autoCommit = True
And then change conn.commit() to the cursor instead
curs.commit()
As a one-liner:
conn.cursor().execute('exec myproc \'data1\';').commit()
* * *
Also, your Python semi-colons (;) at the end of the python line are
unnecessary, and may be doing something weird in your for-loop. (Keep the SQL
ones though.)
|
Encoding with pandas.read_csv when file name has accents
Question: I'm trying to load a CSV with pandas, but am running into a problem if the
file name has accents. It's clearly an encoding problem, but although
`read_csv` lets you set encoding for text within the file, I can't figure out
how to encode the file name properly.
input_file = r'C:\...\Datasets\%s\Provinces\Points\%s.csv' % (country, province)
self.locs = pandas.read_csv(input_file,sep=',',skipinitialspace=True)
The CSV file is Anzoátegui.csv. When I'm getting errors,
input_file = 'C:\\...\Datasets\Venezuela\Provinces\Points\Anzoátegui.csv
Error code:
OSError: File b'C:\\PF2\\QGIS Valmiera\\Datasets\\Venezuela\\Provinces\\Points\\Anzo\xc3\xa1tegui.csv' does not exist
So maybe it's converting my string to bytes? I tried using
`io.StringIO(input_file)` as well, which puts the correct file name as a
column header on an empty `DataFrame`:
Empty DataFrame
Columns: [C:\PF2\QGIS Valmiera\Datasets\Venezuela\Provinces\Points\Anzoátegui.csv]
Index: []
Any ideas on how to get this file to load? Unfortunately I can't just strip
out accents, as I have to interface with software that requires the proper
name, and I have a ton of files to format (not just the one). Thanks!
Edit: Full error
Traceback (most recent call last):
File "C:\PF2\eclipse-standard-kepler-SR2-win32-x86_64\eclipse\plugins\org.python.pydev_3.3.3.201401272249\pysrc\pydevd_comm.py", line 891, in doIt
result = pydevd_vars.evaluateExpression(self.thread_id, self.frame_id, self.expression, self.doExec)
File "C:\PF2\eclipse-standard-kepler-SR2-win32-x86_64\eclipse\plugins\org.python.pydev_3.3.3.201401272249\pysrc\pydevd_vars.py", line 486, in evaluateExpression
result = eval(compiled, updated_globals, frame.f_locals)
File "<string>", line 1, in <module>
File "C:\Python33\lib\site-packages\pandas\io\parsers.py", line 404, in parser_f
return _read(filepath_or_buffer, kwds)
File "C:\Python33\lib\site-packages\pandas\io\parsers.py", line 205, in _read
parser = TextFileReader(filepath_or_buffer, **kwds)
File "C:\Python33\lib\site-packages\pandas\io\parsers.py", line 486, in __init__
self._make_engine(self.engine)
File "C:\Python33\lib\site-packages\pandas\io\parsers.py", line 594, in _make_engine
self._engine = CParserWrapper(self.f, **self.options)
File "C:\Python33\lib\site-packages\pandas\io\parsers.py", line 952, in __init__
self._reader = _parser.TextReader(src, **kwds)
File "parser.pyx", line 330, in pandas.parser.TextReader.__cinit__ (pandas\parser.c:3040)
File "parser.pyx", line 557, in pandas.parser.TextReader._setup_parser_source (pandas\parser.c:5387)
OSError: File b'C:\\PF2\\QGIS Valmiera\\Datasets\\Venezuela\\Provinces\\Points\\Anzo\xc3\xa1tegui.csv' does not exist
Answer: Ok folks, I got a little lost in dependency hell, but it turns out that this
issue was fixed in pandas 0.14.0. Install the updated version to get files
named with accents to import correctly.
[Comments at github](https://github.com/pydata/pandas/issues/7345).
Thanks for the input!
|
How do I load a modified python module?
Question: I'm using the widely used module PySerial
(<http://pyserial.sourceforge.net/index.html#>) for serial communication in
Python. One of it's functions is readline() which reads a line until end of
line '\n'. I created a new function readline_v2() similar to readline() in the
same file serialutil.py. But each time I install the module using "python
install setup.py", it seems as if none of the changes are reflected. The new
function is not detected. What am I doing wrong?
I'm using Windows 8 64 bit. I first downloaded pyserial's source, uncompressed
it, and modified it when I found it didn't work the way I wanted it to.
I tried it using pip also, using "pip install pyserial" but once again there
is no change. I made sure I uninstalled the previous version before
reinstalling. The files don't exist in the "C:/python27/lib/site-packages"
folder after the uninstall. I also deleted all compiled/build files I saw in
the serial package before reinstalling.
Note: In "C:/python27/lib/site-packages", after installation, I can see the
change reflected in the specific file serialutil.py. But I still am unable to
call the function.
Note2: serialutil.py consists of functions of the form-
>
> def readline()
> def readline_v2()
>
This is the only place I added my function since the original function
readline() is defined/used nowhere else.
Final Note: I can't find a fix. But I used a workaround. I defined the new
function in my file after doing an "import serial", instead of modifying the
package itself. Not the ideal solution, but it works fine.
Answer: You need to add the location of your new module to path with sys.path.append()
or alternatively keep the new module in your project directory
|
Kivy Garden in PyInstaller - stuck trying to trace import
Question: I have a Kivy-based Python project that I'm trying to build. It uses the
NavigationDrawer component from Kivy Garden, through an import:
> from kivy.garden.navigationdrawer import NavigationDrawer
I have a PyInstaller spec file for it which builds a distributable version.
This version works well on my machine, but unfortunately not on other
machines. Running the interpreter in the 'dist' version with the -v switch, it
appears that when I run the distributable on my machine, the navigationdrawer
component is not actually coming from inside my build folder. All the other
imports show something like:
> import kivy.graphics.gl_instructions # dynamically loaded from
> C:\Users\me\myapp\dist\RACECA~1\kivy.graphics.gl_instructions.pyd
But the navigationdrawer import says:
> import kivy.garden.navigationdrawer
>
> """directory C:\Users\me\\.kivy\garden\garden.navigationdrawer
> C:\Users\me\\.kivy\garden\garden.navigationdrawer\\__init__.pyc matches
> C:\Users\me\\.kivy\garden\garden.navigationdrawer\\__init__.py import
> kivy.garden.navigationdrawer # precompiled from
> C:\Users\me\\.kivy\garden\garden.navigationdrawer\\__init__.pyc"""
But noo! I don't want you to import them from c:\users. I want them to get
nicely copied into my dist folder like all the other imports. I've tried
adding c:\users\me to PyInstaller's pathex, the system PATH and PYTHONPATH
without any joy. Anyone have any ideas?
Answer: Try installing your garden packages into your app. i.e.
garden install --app navigationdrawer
This will create a libs/garden folder inside the current directory and place
the garden packages in there, which should make it easier to include.
|
Efficient way to aggregate and remove duplicates from very large (password) lists (SOLVED)
Question: Context:
* I am attempting to combine a large amount of separate password list text files into a single file for use in dictionary based password cracking.
* Each text file is line delimited (a single password per line) and there are 82 separate files at the moment. Most (66) files are in the 1-100Mb filesize range, 12 are 100-700Mb, 3 are 2Gb, and 1 (the most problematic) is 11.2Gb.
* In total I estimate 1.75 billion non-unique passwords need processing; of these I estimate ~450 million (%25) will be duplicates and ultimately need to be discarded.
* I am attempting to do this on a device which has a little over 6Gb of RAM free to play with (i.e. 8Gb with 2Gb already consumed).
Problem:
I need a way to a) aggregate all of these passwords together and b) remove
exact duplicates, within my RAM memory constrains and within a reasonable (~7
days, ideally much less but really I don't care if it takes weeks and then I
never need to run it again) time window.
I am a competent Python programmer and thus gave it a crack several times
already. My most successful attempt used sqlite3 to store processed passwords
on the hard disk as it progressed. However this meant that keeping track of
which files had already been completed between processing instances (I
cancelled and restarted several times to make changes) was tediously achieved
by hashing each completed file and maintaining/comparing these each time a new
file was opened. For the very large files however, any progress would be lost.
I was processing the text files in blocks of ~1 billion (at most) lines at a
time to prevent memory exhaustion without having no feedback for extended
periods of time. I know that I could, given a lot of time populate my database
fully as I achieved a DB filesize of ~4.5Gb in 24 hours of runtime so I
estimate that left to run it would take about 4 days at most to get through
everything, but I don't know if/how to most efficiently read/write to it nor
do I have any good ideas on how to tackle the removing of duplicates (do it as
I am populating the DB or make additional passes afterwards...? Is there a
much faster means of doing lookups for uniqueness in a database configuration
I don't know about?).
* * *
My request here today is for advice / solutions to a programming and
optimisation approach on how to achieve my giant, unique password list
(ideally with Python). I am totally open to taking a completely different tack
if I am off the mark already.
* * *
Two nice to haves are:
* A way to add more passwords in the future without having to rebuild the whole list; and
* A database < 20Gb at the end of all this so that it isn't a huge pain to move around.
* * *
**Solution**
Based on CL's solution which was ultimately a lot more elegant than what I was
thinking I came up with a slightly modified method.
Following CL's advice I setup a sqlite3 DB and fed the text files into a
Python script which consumed them and then output a command to insert them
into the DB. Straight off the bat this ~did~ work but was extremely
(infeasibly) slow.
I solved this by a few simple DB optimisations which was much easier to
implement and frankly cleaner to just do all from the core Python script
included below which builds upon CL's skeleton code. The fact that the
original code was generating **sooooooo** many I/O operations was causing
something funny on my (Win7) OS causing BSODs and lost data. I solved this by
making the insertion of a whole password file one SQL transaction plus a
couple of pragma changes. In the end the code runs at about 30,000 insertions
/ sec which is not the best but is certainly acceptable for my purposes.
It may be the case that this will still fail on the largest of files but
if/when that is the case, I will simply chunk the file down into smaller 1Gb
portions and consume them individually.
import sys
import apsw
i = 0
con = apsw.Connection("passwords_test.db")
cur = con.cursor()
cur.execute("CREATE TABLE IF NOT EXISTS Passwords(password TEXT PRIMARY KEY) WITHOUT ROWID;")
cur.execute("PRAGMA journal_mode = MEMORY;")
cur.execute("PRAGMA synchronous = OFF;")
cur.execute("BEGIN TRANSACTION")
for line in sys.stdin:
escaped = line.rstrip().replace("'", "''")
cur.execute("INSERT OR IGNORE INTO Passwords VALUES(?);", (escaped,))
i += 1
if i % 100000 == 0: # Simple line counter to show how far through a file we are
print i
cur.execute("COMMIT")
con.close(True)
This code is then run from command line:
insert_passwords.py < passwordfile1.txt
And automated by:
for %%f in (*.txt) do (
insert_passwords.py < %%f
)
All in all, the DB file itself is not growing too quickly, the insertion rate
is sufficient, I can break/resume operations at the drop of a hat, duplicate
values are being accurately discarded, and the current limiting factor is the
lookup speed of the DB not the CPU or disk space.
Answer: When storing the passwords in an SQL database, being able to detect duplicates
requires an index. This implies that the passwords are stored twice, in the
table and in the index.
However, SQLite [3.8.2](http://www.sqlite.org/releaselog/3_8_2.html) or later
supports [WITHOUT ROWID tables](http://www.sqlite.org/withoutrowid.html)
(called "clustered index" or "index-organized tables" in other databases),
which avoid the separate index for the primary key.
There is no Python version that already has SQLite 3.8.2 included. If you are
not using [APSW](http://code.google.com/p/apsw/), you can still use Python to
create the SQL commands:
1. Install the newest `sqlite3` command-line shell ([download page](http://www.sqlite.org/download.html)).
2. Create a database table:
$ sqlite3 passwords.db
SQLite version 3.8.5 2014-06-02 21:00:34
Enter ".help" for usage hints.
sqlite> CREATE TABLE MyTable(password TEXT PRIMARY KEY) WITHOUT ROWID;
sqlite> .exit
3. Create a Python script to create the INSERT statements:
import sys
print "BEGIN;"
for line in sys.stdin:
escaped = line.rstrip().replace("'", "''")
print "INSERT OR IGNORE INTO MyTable VALUES('%s');" % escaped
print "COMMIT;"
(The INSERT OR IGNORE statement will not insert a row if a duplicate would
violate the primary key's unique constraint.)
4. Insert the passwords by piping the commands into the database shell:
$ python insert_passwords.py < passwords.txt | sqlite3 passwords.db
There is no need to split up input files; fewer transaction have less
overhead.
|
Tkinter Ttk Python: limiting text entry widget values to numbers and limiting amount of characters
Question: Probably an easy one here: in tkinter, ttk, how do you limit the amount of
characters that can be input by the user into an entry field? For example,
only allowing the user to insert one character and limiting the ability to
insert any others?
Additionally, how would I then make it so that only an intiger can be input
into said text entry field, so that it doesn't allow the user to input any
characters that aren't {0:9}?
Thanks :) Btw i'm fairly new to programming so the simpler put, the better :)
If it's any help to showing what to do, here's my program so far:
from tkinter import *
from tkinter import ttk
def calculate(*args):
try:
valuex=int(x.get())
valuey=int(y.get())
valuez=int(z.get())
cappf.set(int(str(valuex)+str(valuey))*10**valuez)
capnf.set(int(str(valuex)+str(valuey))*10**valuez*10**-3)
capuf.set(int(str(valuex)+str(valuey))*10**valuez*10**-6)
except ValueError:
pass
root=Tk()
root.title('Capacitor Calculator')
mainframe=ttk.Frame(root, padding='10 10 10 10')
mainframe.grid(column=0, row=0, sticky=(N, W, E, S))
mainframe.columnconfigure(0, weight=1)
mainframe.rowconfigure(0, weight=1)
x=StringVar()
x_entry=ttk.Entry(mainframe, width=3, textvariable=x)
x_entry.grid(column=1, row=2, sticky=(W,E))
y=StringVar()
y_entry=ttk.Entry(mainframe, width=3, textvariable=y)
y_entry.grid(column=1, row=3, sticky=(W,E))
z=StringVar()
z_entry=ttk.Entry(mainframe, width=3, textvariable=z)
z_entry.grid(column=1, row=4, sticky=(W,E))
cappf=StringVar()
capnf=StringVar()
capuf=StringVar()
ttk.Button(mainframe, width=7, text='Calculate', command=calculate).grid(column=2, row=5, sticky=(N, E, S, W))
ttk.Label(mainframe, textvariable=cappf).grid(column=2, row=2, sticky=N)
ttk.Label(mainframe, textvariable=capnf).grid(column=2, row=3, sticky=N)
ttk.Label(mainframe, textvariable=capuf).grid(column=2, row=4, sticky=N)
ttk.Label(mainframe, text='Input:').grid(column=1, row=1, sticky=N)
ttk.Label(mainframe, text='Amount:').grid(column=2, row=1, sticky=N)
ttk.Label(mainframe, text='Units:').grid(column=3, row=1, sticky=N)
ttk.Label(mainframe, text='pf').grid(column=3, row=2, sticky=N)
ttk.Label(mainframe, text='nf').grid(column=3, row=3, sticky=N)
ttk.Label(mainframe, text='uf').grid(column=3, row=4, sticky=N)
ttk.Button(mainframe, width=7, text='Quit', style='red.TButton', command=root.destroy).grid(column=2, row=6, sticky=(N, E, S, W))
ttk.Style().configure('red.TButton', foreground='red', padding=6, font='Corbel 18')
ttk.Style().configure('TLabel', padding=6, font='Corbel 16', foreground='#0077AF')
ttk.Style().configure("TButton", padding=6, relief="flat", font='Corbel 18', foreground='#00AA11')
for child in mainframe.winfo_children(): child.grid_configure(padx=5, pady=3)
x_entry.focus()
y_entry.focus()
z_entry.focus()
root.bind('<Return>', calculate)
root.mainloop()
Answer: The entry widget supports a validation callback, specified by setting the
validation mode (via the `validate` property) and providing the callback
itself (via the `validatecommand` property). The Tkinter documentation for how
to use it is very poor, unfortunately.
The validation mode can be the strings `focusOut` (to apply the validation
when the focus leaves the widget) and `key` (to apply it when the user presses
a key). And `focus` and `focusIn` but I've not found them to be so useful.
The validation callback should return a boolean that states whether the
current (== new, in the case of `key` validation) contents are valid. If the
validation fails, the change is rejected (the contents are reset) and the
invalid contents callback is invoked (via the `invalidcommand` property) which
can do things like sound the bell or make the screen flash.
* * *
A more elaborate validation mechanism is to always _officially_ claim that the
edit is valid, but to change the background of the entry (or use some other
indicator) to show that the edit _will be rejected_. Then, only do full
validation/rejection on overall submission of the form (you were going to do
that anyway, yes?). Like that, temporarily invalid states are permitted so
long as the user goes back and fixes them before finishing their session. This
is quite a lot more usable.
|
Best way to package a Python library that includes a C shared library?
Question: I have written a library whose main functionality is implemented in C (speed
is critical), with a thin Python layer around it to deal with the `ctypes`
nastiness.
I'm coming to package it and I'm wondering how I might best go about this. The
code it must interface with is a shared library. I have a Makefile which
builds the C code and creates the `.so` file, but I don't know how I compile
this via distutils. Should I just call out to `make` with `subprocess` by
overriding the `install` command (if so, is `install` the place for this, or
is `build` more appropriate?)
**Update** : I want to note that this is _not_ a Python extension. That is,
the C library contains no code to itself interact with the Python runtime.
Python is making foreign function calls to a straight C shared library.
Answer: Given that you followed the instructions on how to [create Python extensions
in C](https://docs.python.org/2/extending/extending.html), you should just
enlist the extension modules like in [this
documentation](https://docs.python.org/2/distutils/setupscript.html#describing-
extension-modules).
So the `setup.py` script of your library should look like this:
from distutils.core import setup, Extension
setup(
name='your_python_library',
version='1.0',
ext_modules=[Extension('your_c_extension', ['your_c_extension.c'])],
)
and `distutils` knows how to compile your extension to C shared library and
moreover where to put it.
_Of course I have no further information about your library, so you probably
want to add more arguments to`setup(...)` call._
|
AttributeError: "'NoneType' object has no attribute 'path'" in <function _remove at 0x10c49a668> ignored
Question: I'm trying to implement my coursera python project in flask environment. Also
I'm using the <https://github.com/miguelgrinberg/flasky> (branch 7a) to
understand how the blueprints work. Now, I define 2 blueprints: main_blueprint
& rpsls_blueprint. And get the following error after running application:
Traceback (most recent call last):
File "manage.py", line 8, in <module>
app = create_app(os.getenv('FLASK_CONFIG') or 'default')
File "..../app/__init__.py", line 29, in create_app
app.register_blueprint(rpsls_blueprint)
File "/Library/Python/2.7/site-packages/flask/app.py", line 62, in wrapper_func
return f(self, *args, **kwargs)
File "/Library/Python/2.7/site-packages/flask/app.py", line 880, in register_blueprint
if blueprint.name in self.blueprints:
AttributeError: 'module' object has no attribute 'name'
Exception AttributeError: "'NoneType' object has no attribute 'path'" in <function _remove at 0x10c49a668> ignored
Does someone know where the problem is? Here is the related part of my
`app/__init__.py` file:
def create_app(config_name):
app = Flask(__name__)
app.config.from_object(config[config_name])
config[config_name].init_app(app)
bootstrap.init_app(app)
mail.init_app(app)
moment.init_app(app)
db.init_app(app)
from .main import main as main_blueprint
app.register_blueprint(main_blueprint)
from .rpsls import rpsls as rpsls_blueprint
app.register_blueprint(rpsls_blueprint)
return app
Here is my app/rpsls/rpsls.py file:
import random
class RpslsGame():
def __init__(self):
pass
def name_to_number(self, name):
if name == "rock":
return 0
elif name == "Spock":
return 1
elif name == "paper":
return 2
elif name == "lizard":
return 3
elif name == "scissors":
return 4
else:
return name + " does not match any\
of the five correct input strings"
def number_to_name(self, number):
if number == 0:
return "rock"
elif number == 1:
return "Spock"
elif number == 2:
return "paper"
elif number == 3:
return "lizard"
elif number == 4:
return "scissors"
else:
return str(number) + \
" is not in the correct range"
def rpslsMethod(self, player_choice):
result = ""
result += "Player chooses " + str(player_choice) + "\n"
player_number = self.name_to_number(player_choice)
comp_number = random.randrange(0, 5)
comp_choice = self.number_to_name(comp_number)
result += "Computer chooses " + comp_choice + "\n"
differene = (comp_number - player_number) % 5
if (differene == 1 or differene == 2):
result += "Computer wins\n"
elif (differene == 3 or differene == 4):
result += "Player wins\n"
elif (differene == 0):
result += "Try again, It's a tie\n"
return result
My app/rpsls/**init**.py file:
from flask import Blueprint
rpsls = Blueprint('rpsls', __name__)
from . import views
Answer: You imported the `rpls` module from the `rpls` package. That's a _module_ ,
not a blueprint object.
You cannot register a module as a blueprint; you can only register
[`flask.Blueprint()`
instances](https://flask.readthedocs.org/en/latest/api/#flask.Blueprint). You
may want to read up on how [Flask Blueprints
work](https://flask.readthedocs.org/en/latest/blueprints/).
You have both a `rpls` object in the `rpls` package, _and_ a submodule. When
the `app.rpls.rpls` module is imported, it **replaced** the `rpls` `Blueprint`
instance in your `__init__.py` file; the namespaces are not separate.
Rename one or the other; the module or the `Blueprint` object.
|
Django Error: __init__() takes exactly 2 arguments (3 given)
Question: Anyone can find what is causing the error in my code? I already searched, but
didn't find an answer. I think the problem is with the function
objects.get(param), but I'm not sure.
What I wanted to do with my code was to retrieve the objects Genre, Country,
Language and Directors if they were already added to the database.
Here's the code:
Models.py
from django.db import models
from numpy import unique
class Director(models.Model):
director = models.CharField(max_length=500, unique=True)
def __unicode__(self):
return self.director
def __init__(self, director):
super(Director, self).__init__()
self.director = director
class Language(models.Model):
language = models.CharField(max_length=500, unique=True)
def __unicode__(self):
return self.language
def __init__(self, language):
super(Language, self).__init__()
self.language = language
class Genre(models.Model):
genre = models.CharField(max_length=500, unique=True)
def __unicode__(self):
return self.genre
def __init__(self, genre):
super(Genre, self).__init__()
self.genre = genre
class Country(models.Model):
country = models.CharField(max_length=500, unique=True)
def __unicode__(self):
return self.country
def __init__(self, country):
super(Country, self).__init__()
self.country = country
class Movie(models.Model):
id_movie = models.CharField(max_length=200, unique=True)
rating = models.CharField(max_length=200)
votes = models.CharField(max_length=200)
year = models.CharField(max_length=10)
genre = models.ManyToManyField(Genre)
country = models.ManyToManyField(Country)
language = models.ManyToManyField(Language)
directors = models.ManyToManyField(Director)
def __init__(self, id_movie, rating, votes, year):
super(Movie, self).__init__()
self.id_movie = id_movie
self.rating = rating
self.votes = votes
self.year = year
def __unicode__(self):
return self.id_movie
crawler.py
from movie_info.models import Movie, Genre, Director, Language, Country
def get_movie_info(codigo_do_filme):
import imdb
ia = imdb.IMDb()
movie = ia.get_movie(codigo_do_filme)
return {'titulo': movie['title'], 'rating': movie['rating'], 'votes': movie['votes'], 'ano': movie['year'], 'genero': movie['genre'][0], 'pais': movie['countries'][0], 'idioma': movie['lang'][0], 'directors': movie['director']}
def read_sheet(file_name, fieldnames=None, delimiter=",", quotechar="\n"):
from csv import DictReader
reader = DictReader(open(file_name,'rb'), fieldnames = fieldnames, delimiter = delimiter, quotechar=quotechar)
return reader
def fill_db_movie_info(the_sheet_file):
file_csv = read_sheet(the_sheet_file)
for movie in file_csv:
id_filme = movie['id_move']
if not Movie.objects.filter(id_movie=id_filme).exists():
info = get_movie_info(id_filme)
rating_imdb = info['rating']
movie_votes = info['votes']
movie_year = info['ano']
movie_genre = info['genero']
movie_country = info['pais']
movie_lang = info['idioma']
movie_directors = info['directors']
addToDB = Movie(id_filme, rating_imdb, movie_votes, movie_year)
addToDB.save()
if not Genre.objects.filter(genre=movie_genre).exists():
genreToDB = Genre(movie_genre)
genreToDB.save()
addToDB.genre.add(genreToDB)
else:
addToDB.genre.add(Genre.objects.get(genre=movie_genre))
if not Country.objects.filter(country=movie_country).exists():
countryToDB = Country(movie_country)
countryToDB.save()
addToDB.country.add(countryToDB)
else:
addToDB.country.add(Country.objects.get(country=movie_country))
if not Language.objects.filter(language=movie_lang).exists():
langToDB = Language(movie_lang)
langToDB.save()
addToDB.language.add(langToDB)
else:
addToDB.language.add(Language.objects.get(language=movie_lang))
for m_director in movie_directors:
if not Director.objects.filter(director=m_director['name']).exists():
directorsToDB = Director(m_director['name'])
directorsToDB.save()
addToDB.directors.add(directorsToDB)
else:
addToDB.directors.add(Director.objects.get(director=m_director['name']))
print "salvou: " + id_filme, rating_imdb, movie_votes, movie_year, movie_genre, movie_country, movie_lang, movie_directors[0]
The Traceback:
pydev debugger: starting (pid: 1424)
Traceback (most recent call last):
File "/Applications/eclipse/plugins/org.python.pydev_3.5.0.201405201709/pysrc/pydevd.py", line 1845, in <module>
debugger.run(setup['file'], None, None)
File "/Applications/eclipse/plugins/org.python.pydev_3.5.0.201405201709/pysrc/pydevd.py", line 1373, in run
pydev_imports.execfile(file, globals, locals) # execute the script
File "/Users/rubenspessoa/Documents/Workspace/LearningDjango/main.py", line 7, in <module>
fill_db_movie_info('/Users/rubenspessoa/Documents/Workspace/DATASET/test_subdataset.csv')
File "/Users/rubenspessoa/Documents/Workspace/LearningDjango/crawler.py", line 49, in fill_db_movie_info
addToDB.country.add(Country.objects.get(country=movie_country))
File "/Library/Python/2.7/site-packages/django/db/models/manager.py", line 151, in get
return self.get_queryset().get(*args, **kwargs)
File "/Library/Python/2.7/site-packages/django/db/models/query.py", line 304, in get
num = len(clone)
File "/Library/Python/2.7/site-packages/django/db/models/query.py", line 77, in __len__
self._fetch_all()
File "/Library/Python/2.7/site-packages/django/db/models/query.py", line 857, in _fetch_all
self._result_cache = list(self.iterator())
File "/Library/Python/2.7/site-packages/django/db/models/query.py", line 230, in iterator
obj = model(*row_data)
TypeError: __init__() takes exactly 2 arguments (3 given)
Answer: You have defined `__init__` methods for all your models. You should not do
that.
|
How is semaphore variable passed into the following object in python?
Question: After tweaking with this piece of code a few times, I dropped sem.release() in
the Server object WITHOUT actually passing the variable sem into it. But it
works wonderfully... Can't seem to understand why a error wasn't throw for
undeclared variable/reference
import threading,time
class Server(threading.Thread):
def __init__(self, hostname):
super(Server, self).__init__()
self.__hostname = hostname
def run(self):
print self.__hostname+' left'
time.sleep(5)
print self.__hostname+' back'
sem.release()
#init
sem = threading.BoundedSemaphore(2)
for x in xrange(1,8):
sem.acquire()
Server('thread '+str(x)).start()
Answer: There's nothing special about accessing a global variable inside a class.
x = 3
class xprinter(object):
def __init__(self):
print(x)
xprinter()
output:
3
|
How can I use "include.yaml" in google appengine to share a library within two apps?
Question: I have two different applications on GAE, but both have some code in common.
I wanted to share that code but I can't find a way to import a .py file that's
not in the same directory as the main app.
I think that "includes" in the yaml file could be what I need
(<https://developers.google.com/appengine/docs/python/config/appconfig#Python_app_yaml_Includes>)
but I can't find any example on how to use it.
I understand I need an include.yaml file, but what should I write in it!?
Is there some more documentation I'm missing?
I can't find a way to import that code in my main app... is there any?
Answer: Thats not necessary.
Make sure you include the path to the file with `sys.setpath()` pointing to
the directory containing the other python code, and put an `__init__.py` in
that directory.
The best place to do this is in `appengine_config.py`
|
detect key press in python?
Question: I am making a stopwatch type program in python and I would like to know how to
detect if a key is pressed (such as p for pause and s for stop), and I would
not like it to be something like raw_input that waits for the user's input
before continuing execution. Anyone know how to do this in a while loop?
Also, I would like to make this cross-platform, but if that is not possible,
then my main development target is linux
Answer: Use PyGame to have a window and then you can get the key events.
**For the letter`p`:**
import pygame, sys
import pygame.locals()
pygame.init()
BLACK = (0,0,0)
WIDTH = 1280
HEIGHT = 1024
windowSurface = pygame.display.set_mode((WIDTH, HEIGHT), 0, 32)
windowSurface.fill(BLACK)
while True:
events = pygame.event.get()
for event in events:
if event.key == pygame.K_p:
#Do what you want to here
pass
if event.type == QUIT:
pygame.quit()
sys.exit()
|
python motor mongo cursor length or peek next
Question: is there a way of determining the length of the motor mongo cursor or peeking
ahead to see if there is a next ( instead of `fetch_next` perhaps `has_next` )
and not the `cursor.size()` that does not take into the provided limit()
basically i desire to add the required json comma
while (yield cursor.fetch_next):
document = cursor.next_object()
print document
if cursor.has_next() # Sweeet
print ","
Answer: You can use the "alive" property. Try running this:
from tornado import gen, ioloop
import motor
client = motor.MotorClient()
@gen.coroutine
def f():
collection = client.test.collection
yield collection.drop()
yield collection.insert([{'_id': i} for i in range(100)])
cursor = collection.find()
while (yield cursor.fetch_next):
print cursor.next_object(), cursor.alive
ioloop.IOLoop.current().run_sync(f)
It prints "True" until the final document, when alive is "False".
A MotorCursor fetches data from the server in batches. ([The MongoDB
documentation on batches](http://docs.mongodb.org/manual/core/cursors/#cursor-
batches) explains how cursors and batches work for all MongoDB drivers,
including Motor.) When "alive" is True it means either that there is more data
available on the server, or data is buffered in the MotorCursor, or both.
There is a race condition, however. Say that you fetch all but the final
document, and before you fetch that last document another client deletes it,
then you'll fail to find the last document even though "alive" was "True".
Better to rearrange your loop:
@gen.coroutine
def f():
collection = client.test.collection
yield collection.drop()
yield collection.insert([{'_id': i} for i in range(100)])
cursor = collection.find()
if (yield cursor.fetch_next):
sys.stdout.write(str(cursor.next_object()))
while (yield cursor.fetch_next):
sys.stdout.write(", ")
sys.stdout.write(str(cursor.next_object()))
print
|
how to access global variable within __main__ scope?
Question: I'm confused about the namespace and scope of variables in python
Suppose I have a test.py:
# -*- coding: utf-8 -*-
"""
@author: jason
"""
if __name__ == '__main__':
global strName
print strName
and then, I define a variable named strName and try to access it in the
test.py, but it throws an error:
In [9]: strName = "Joe"
In [10]: run test.py hello
--------------------------------------------------------------------------- NameError Traceback (most recent call last) C:\Anaconda\lib\site-packages\IPython\utils\py3compat.pyc in execfile(fname, glob, loc)
195 else:
196 filename = fname
--> 197 exec compile(scripttext, filename, 'exec') in glob, loc
198 else:
199 def execfile(fname, *where):
d:\playground\test.py in <module>()
13 print "hello"
14 global strName
---> 15 print strName
16
NameError: global name 'strName' is not defined
In [11]:
I was wondering why this happens and is there any way to access strName in
test.py?
Answer: **test.py:**
strName = "John Doe"
print strName
**Interactive Shell:**
$ python
>>> from test import strName
>>> print strName
John Doe
|
from qgis.core import QgsFeature, QgsGeometry. DLL load failed
Question: I recently installed QGIS and I want to import qgis module of Python. I use
Windows 7 x64 and QGIS 2.2 x64. I set the PATH to :
C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files\Intel\WiFi\bin\;C:\Program Files\Common Files\Intel\WirelessCommon\;C:\mapnik-v2.2.0\lib;C:\mapnik-v2.2.0\bin;C:\Program Files (x86)\QGIS Valmiera\apps\qgis\python;C:\OSGeo4W\bin;E:\Python\GeoDjango\myplanet;E:\Python\GeoDjango\myplanet;C:\Program Files (x86)\QGIS Valmiera\bin;C:\Program Files (x86)\QGIS Valmiera\apps\msys\bin;C:\Program Files (x86)\QGIS Valmiera\apps\Python27;C:\Program Files (x86)\QGIS Valmiera\bin;C:\Program Files (x86)\QGIS Valmiera\apps\qgis\python\qgis;
and PYTHONPATH to:
C:\mapnik-v2.2.0\python\2.7\site-packages;E:\Python\GeoDjango\myplanet;C:\Program Files\QGIS Valmiera\apps\qgis\python;C:\Program Files\QGIS Valmiera\apps\Python27\lib;C:\Program Files\QGIS Valmiera\apps\Python27\Lib\site-packages;C:\Program Files\QGIS Valmiera\apps\Python27\DLLs;
I still get this error:
import qgis
File "C:\Program Files\QGIS Valmiera\apps\qgis\python\qgis\__init__.py", line 35, in <module>
from qgis.core import QgsFeature, QgsGeometry
ImportError: DLL load failed: The specified module could not be found.
I used Dependency Walker to track the problems with the DLL load. this is the
screenshot of Dependency Walker: 
Error: At least one module has an unresolved import due to a missing export function in an implicitly dependent module.
Error: Modules with different CPU types were found.
Warning: At least one module has an unresolved import due to a missing export function in a delay-load dependent module.
How can I fix the errors?
Answer: See here: [DLL load failed with
PyQGIS](http://stackoverflow.com/questions/14334000/dll-load-failed-with-
pyqgis/25269980#25269980)
import sys
sys.path.extend([r"C:\Program Files\QGIS Valmiera\apps",r"C:\Program Files\QGIS Valmiera\apps\qgis\bin",r"C:\Program Files\QGIS Valmiera\apps\Python27"])
import qgis.core
|
Python: Trouble with encoding on Windows (Bokeh plotting library)
Question: I am trying to reproduce the simplest examples from the [Bokeh
tutorial](http://bokeh.pydata.org/tutorial/basic.html), on a 64-bit Windows
machine with Python 3.3.0.
Here is the code in its entirety
import pandas as pd
import numpy as np
import matplotlib.pyplot as mpl
# NOTE need this import as output_file was not getting imported into the
# global namespace
import bokeh.plotting as bkp
from bokeh.plotting import *
# Skip the first point because it can be troublesome
theta = np.linspace(0, 8*np.pi, 10000)[1:]
# Compute the radial coordinates for some different spirals
lituus = theta**(-1/2) # lituus
golden = np.exp(0.306349*theta) # golden
arch = theta # Archimedean
fermat = theta**(1/2) # Fermat's
# Now compute the X and Y coordinates (polar mappers planned for Bokeh later)
golden_x = golden*np.cos(theta)
golden_y = golden*np.sin(theta)
lituus_x = lituus*np.cos(theta)
lituus_y = lituus*np.sin(theta)
arch_x = arch*np.cos(theta)
arch_y = arch*np.sin(theta)
fermat_x = fermat*np.cos(theta)
fermat_y = fermat*np.sin(theta)
# output to static HTML file
bkp.output_file("lines.html")
# Plot the Archimedean spiral using the `line` renderer. Note how we set the
# color, line thickness, title, and legend value.
line(arch_x, arch_y, color="red", line_width=2, title="Archimean", legend="Archimedean")
This gives me the following error:
Traceback (most recent call last):
File "F:\programming\python\python64\python33\lib\site-packages\IPython\core\interactiveshell.py", line 2732, in run_code
exec(code_obj, self.user_global_ns, self.user_ns)
File "<ipython-input-1-00be3b4eba05>", line 1, in <module>
bkp.line(arch_x, arch_y, color="red", line_width=2, title="Archimean", legend="Archimedean")
File "F:\programming\python\python64\python33\lib\site-packages\bokeh\plotting.py", line 318, in wrapper
save()
File "F:\programming\python\python64\python33\lib\site-packages\bokeh\plotting.py", line 284, in save
f.write(html)
File "F:\programming\python\python64\python33\lib\encodings\cp1252.py", line 19, in encode
return codecs.charmap_encode(input,self.errors,encoding_table)[0]
UnicodeEncodeError: 'charmap' codec can't encode characters in position 1831286-1831289: character maps to <undefined>
I understand that this has something to do with the encoding that Python is
using to write to the output file, but don't know enough about setting the
encoding of the output file or the encoding that is being used by Python to
write out to fix this. Help appreciated.
## Edit:
I tried to implement the advice given
[here](http://www.macfreek.nl/memory/Encoding_of_Python_stdout), to always
pass stdout output through a streamwriter:
if sys.stdout.encoding != 'UTF-8':
sys.stdout = codecs.getwriter('utf-8')(sys.stdout.buffer, 'strict')
if sys.stderr.encoding != 'UTF-8':
sys.stderr = codecs.getwriter('utf-8')(sys.stderr.buffer, 'strict')
but some of the interface appears to have changed, and there is no
`sys.stdout.encoding` variable.
Traceback (most recent call last):
File "F:\programming\python\python64\python33\lib\site-packages\IPython\core\interactiveshell.py", line 2732, in run_code
exec(code_obj, self.user_global_ns, self.user_ns)
File "<ipython-input-1-e12310bc7a07>", line 1, in <module>
if sys.stdout.encoding != 'UTF-8':
File "F:\programming\python\python64\python33\lib\codecs.py", line 387, in __getattr__
return getattr(self.stream, name)
AttributeError: '_io.FileIO' object has no attribute 'encoding'
Answer: I have opened an issue to track this problem:
<https://github.com/ContinuumIO/bokeh/issues/682>
As you have discussed with eryksun, it seems easily fixable.
I will keep you updated here, but if you want to participate in the issue, you
are very welcome.
Cheers
|
python 2.7 imaplib error
Question: I tried to connect to my mail server via imaplib and got an error in
constructor: My code:
import imaplib
imaplib.IMAP4_SSL('my_host.com', 1234)
Error:
Traceback (most recent call last)
/home/username/www/site/<ipython console> in <module>()
/usr/lib/python2.7/imaplib.py in __init__(self, host, port, keyfile, certfile)
1163 self.keyfile = keyfile
1164 self.certfile = certfile
-> 1165 IMAP4.__init__(self, host, port)
1166
1167
/usr/lib/python2.7/imaplib.py in __init__(self, host, port)
197 self.state = 'NONAUTH'
198 else:
--> 199 raise self.error(self.welcome)
200
201 typ, dat = self.capability()
error: None
Python recieved response from server and then raise an error, but it's a
normal continuation response. Response from server:
+OK my_host.com POP3 MDaemon 12.5.6 ready <MDAEMON-F201406061147.AA472534MD1387@my_host.com>
What I should do to recieve my mails from my server?
Answer: Demon point that he using protocol POP3. You are trying to communicate whit
him using IMAP protocol. Change lib to poplib or change port to communicate
via IMAP protocol(default is 143).
|
How to create graphic slider in Python that can be modified with mouse?
Question: How can i create a graphic slider similar to a progress bar in PyQt that can
be modified from 0 to 100 with mouse?
Answer: You have to set QSlider stylesheet appropriately. This solution is based on
PyQt5
import sys
from PyQt5 import QtGui, QtCore, QtWidgets
class MyApp(object):
def __init__(self):
super(MyApp, self).__init__()
self.mainWidget = QtWidgets.QWidget()
self.mainLayout = QtWidgets.QVBoxLayout()
self.mainWidget.setLayout(self.mainLayout)
self.slider = QtWidgets.QSlider()
self.slider.setOrientation(QtCore.Qt.Horizontal)
self.slider.setStyleSheet(self.stylesheet())
self.mainLayout.addWidget(self.slider)
self.mainWidget.show()
sys.exit(app.exec_())
def stylesheet(self):
return """
QSlider::groove:horizontal {
background: white;
height: 40px;
}
QSlider::sub-page:horizontal {
background: qlineargradient(x1: 0, y1: 0, x2: 0, y2: 1,
stop: 0 #66e, stop: 1 #bbf);
background: qlineargradient(x1: 0, y1: 0.2, x2: 1, y2: 1,
stop: 0 #bbf, stop: 1 #55f);
height: 40px;
}
QSlider::add-page:horizontal {
background: #fff;
height: 40px;
}
QSlider::handle:horizontal {
background: #bbf;
border: 0px;
width: 0px;
margin-top: 0px;
margin-bottom: 0px;
border-radius: 0px;
}
"""
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
MyApp()
and this is the output component
|
Python Searching and returning text inside parentheses
Question: Okay, I have read many similar questions and tried them out but it's not
working for some reason. I have a file with a bunch of lines that look like
this:
Here are some words:
"<Hello> (silly girl) that isn't what she want(s)"
I am trying to search for text of two or more characters within parentheses.
Many combinations of `re.search` and `group()` returns something, but not
exactly what I'm looking for. The value I want returned and printed in this
case is: `"silly girl"`.
Right now I have this:
regex = re.compile("\((.+.+)\)")
for line in lines:
m = re.search(regex, line)
if m:
print(m.group())
The above prints:
(silly girl) that isn't what she want(s)
If I change the group index to `1`, as in `print(m.group(1))`, it prints the
same thing just without the first parentheses:
silly girl) that isn't what she want(s)
What am I doing wrong?
Answer: Regular expressions are _greedy_ by default, so capture from the first `'('`
(before `'silly'`) to the last (after `'want(s'`). Instead:
* Make it a _lazy_ match with `'?'`;
* Use `'[^()]'` rather than `'.'` to exclude parentheses from the match (thanks to @thg435, and see their comment on the question for a potential drawback);
* Use `'{2,}'` to indicate "two or more", rather than two separate "one or more" `'+'`s; and
* Include a capturing group to exclude the parentheses themselves.
Now you have:
regex = re.compile(r"\(([^()]{2,}?)\)")
This lets you switch to `findall` to get a list of results:
>>> import re
>>> regex = re.compile(r"\(([^()]{2,}?)\)")
>>> s = "<Hello> (silly girl) that isn't what she want(s)"
>>> m = re.findall(regex, s)
>>> m
['silly girl']
See a demo of the regex [here](http://regex101.com/r/yI2iN6).
|
Create crontab with python-crontab in Python?
Question: I am trying to add a line to my system user's crontab, from a Python script
which uses the package python-crontab. My crontab file does not exist yet, and
when I run this code, nothing happens (no errors, no results, no creation of
crontab file):
from crontab import CronTab
cron = CronTab(user=True)
# cron = CronTab(user='my_user') I tried this line too without any results
job = cron.new(command='python3 /opt/my_script.py')
job.minute.on(2)
job.hour.on(12)
True == job.is_valid()
Am I missing anything?
Answer: You need to save the cronjob, that's all that's missing:
#!/bin/python
from crontab import CronTab
cron = CronTab(user=True)
job = cron.new(command='python3 /opt/my_script.py')
job.minute.on(2)
job.hour.on(12)
cron.write()
|
Auto running a script in python
Question: I'm looking for a script that auto spams pictures of nicholas cage on the
desktop I have this script right now but what I want to do is make it
automatically run as soon as the USB is plugged in
import shutil
src = ('Kim.jpg')
dst = ('H:/profile/desktop/Nic')
count = 1
while count < 10:
shutil.copyfile(src, dst + str(count) + ".jpg")
count += 1
Answer: **Assumption** : You are using Windows.
Almost on every new windows platform you need to approve an autorun of any
executable so no leads here. But here is an alternative using some
social/psychological engineering:
Convert your program to a standalone executable using a tool like `py2exe`. I
assume that after conversion your file is named `spammer.exe`. Then paste this
file in the USB and super-hide it by opening Command Prompt inside your USB
and typing:
attrib +h +s +r spammer.exe
Now create a shortcut with and icon of a typical folder of Windows and name it
something attractive (if you know what I mean) and point it to `spammer.exe`.
The user (in excitement) clicks at it and Kaboom!
|
trac ticketlog.web_ui error when browsing trac
Question: I am receiving the following errors. i am using trac 0.12 on centos 5. I have
plugins, advancedticketworkflow, ldaplugin, smtpldapemailsender,
tracannouncer, tracwysiwg. i am trying to install commit ticket updater and
similar plugins but they are not showing up. nor is it working.
rac[paradox:loader] ERROR: Skipping "ticketlog = ticketlog.web_ui":
Traceback (most recent call last):
File "/usr/lib/python2.4/site-packages/Trac-0.12.5-py2.4.egg/trac/loader.py", line 68, in _load_eggs
entry.load(require=True)
File "/usr/lib/python2.4/site-packages/setuptools-0.6c11-py2.4.egg/pkg_resources.py", line 1954, in load
entry = __import__(self.module_name, globals(),globals(), ['__name__'])
File "/usr/lib/python2.4/site-packages/TracTicketChangelogPlugin-0.1-py2.4.egg/ticketlog/web_ui.py", line 45, in ?
import json as simplejson
ImportError: No module named json
Trac[paradox:loader] ERROR: Skipping "tickettemplate = tickettemplate.ttadmin":
Traceback (most recent call last):
File "/usr/lib/python2.4/site-packages/Trac-0.12.5-py2.4.egg/trac/loader.py", line 68, in _load_eggs
entry.load(require=True)
File "/usr/lib/python2.4/site-packages/setuptools-0.6c11-py2.4.egg/pkg_resources.py", line 1954, in load
entry = __import__(self.module_name, globals(),globals(), ['__name__'])
File "/usr/lib/python2.4/site-packages/TracTicketTemplate-0.7-py2.4.egg/tickettemplate/ttadmin.py", line 213
with open(json_template_file) as f:
^
SyntaxError: invalid syntax (ttadmin.py, line 213)
Trac[paradox:loader] ERROR: Skipping "tickettemplate = tickettemplate.ttadmin":
Traceback (most recent call last):
File "/usr/lib/python2.4/site-packages/Trac-0.12.5-py2.4.egg/trac/loader.py", line 68, in _load_eggs
entry.load(require=True)
File "/usr/lib/python2.4/site-packages/setuptools-0.6c11-py2.4.egg/pkg_resources.py", line 1954, in load
entry = __import__(self.module_name, globals(),globals(), ['__name__'])
File "/usr/lib/python2.4/site-packages/TracTicketTemplate-0.7-py2.4.egg/tickettemplate/ttadmin.py", line 213
with open(json_template_file) as f:
^
SyntaxError: invalid syntax (ttadmin.py, line 213)
**UPDATE**
I checked out latest version, when i run setup.py i get the following error
python setup.py
File "setup.py", line 55
install_requires=['simple_json' if sys.version_info < (2, 6) else ''],
^
SyntaxError: invalid syntax
rpm -qa | grep -i python
python-2.4.3-19.el5
dbus-python-0.70-7.el5
python-sqlite2-2.6.3-1.el5.rf
python-iniparse-0.2.3-6.el5
libxml2-python-2.6.26-2.1.2
python-sqlite-1.1.7-1.2.1
python-elementtree-1.2.6-5
mod_python-3.2.8-3.1
MySQL-python-1.2.1-1
python-ldap-2.2.0-2.1
libselinux-python-1.33.4-2.el5
audit-libs-python-1.3.1-1.el5
rpm-python-4.4.2-37.el5
python-devel-2.4.3-19.el5
python-simplejson-2.0.9-8.el5
python-urlgrabber-3.1.0-2
postgresql-python-8.1.9-1.el5
python-json-3.4-3.el5
Answer: [TracTicketChangelogPlugin](http://trac-
hacks.org/wiki/TracTicketChangelogPlugin) and
[TracTicketTemplatePlugin](http://trac-
hacks.org/wiki/TracTicketTemplatePlugin) do not support Python 2.4.
TracTicketChangelogPlugin might support Python 2.4 if you install the
`simplejson` package. TracTicketTemplatePlugin utilizes the `with_statement`
so we'll need to add `from __future__ import with_statement` to get it to work
with Python 2.5.
|
Why is `subprocess.call` not invoking the command
Question: I'm trying to run a .wav file through ffmpeg using the
`subprocess.call(shell=True)` in the following code and it doesn't seem to
run. I know this because the `output_file` isn't created and I'm getting an
exception in the `open()` method. What am I doing wrong?
try:
import pocketsphinx
except:
import pocketsphinx as ps
import sphinxbase
import subprocess
import os
hmmd = "../../Pocketsphinx_Files/en-us-8khz"
lmdir = "../../Pocketsphinx_Files/cmusphinx-5.0-en-us.lm"
dictp = "../../Pocketsphinx_Files/cmu07a.dic"
output_filename = "../../temp/ps_output.wav"
def recognize(filename="../../temp/temp_output.wav"):
command = "ffmpeg -i "+filename+" -ac 1 -ab 16 -ar 16000 "+output_filename
subprocess.call(command,shell=True)
wavFile = open(output_filename,"rb")
speechRec = ps.Decoder(hmm = hmmd, lm = lmdir, dict = dictp)
wavFile.seek(44)
speechRec.decode_raw(wavFile)
result = speechRec.get_hyp()
#os.remove(filename)
#os.remove(output_filename)
return result
if __name__=="__main__":
print(recognize())
edit: I've got ffmpeg installed. Furthermore, when I run the subprocess.call()
command from the python interpreter it seems to work. This is why I'm stumped.
Answer: I would recommend that you try using `subprocess.check_call()` or
`check_output` instead of simply `call`. They will raise an exception if your
program fails to execute correctly, instead of leaving you wondering why no
output was generated.
I'm going to guess that you may somehow be having path issues with your
executable in a Python environment
Try using this function with 'ffmpeg':
def is_exe(prog):
for path in os.environ["PATH"].split(os.pathsep):
if os.path.isfile(os.path.join(path, prog)):
if os.access(os.path.join(path, prog), os.X_OK):
return os.path.join(path, prog)
else:
print "Program '%s' found in '%s', but lacks executable permissions." % (prog, path)
return False
If it returns `False`, you're having problems with Python running ffmpeg,
otherwise it's ffmpeg which is having problems making sense of your arguments.
|
Prevent Python from showing entered input
Question: In Python when I change the value of a variable through raw_input in the
terminal it would write a new line stating its new value. I wanted to know if
there is a way to avoid that because straight after user's input there is a
print function which uses the value received before. In the end the user will
get both values: original and modified while for the purpose of my program he
only has to see the modified.
I use IDLE to write my scripts and then execute them in terminal.
**Update**
A simple example would be the following. The input is string "Hello" and the
output should be "Me: Hello". There should be no "Hello" before the final
result.
a = raw_input()
print ("Me: " + a)
And the output should be just
Me: Hello
rather than
Hello
Me: Hello
Answer: if you want user to see the input, just mute `sys.stdout` (it's a bit hack
tho):
>>> from StringIO import StringIO
>>> import sys
>>> orig_out = sys.stdout
>>> print 'give me input: ',
give me input:
>>> sys.stdout = StringIO()
>>> a = raw_input('')
string I type
>>> sys.stdout = orig_out
>>> a
>>> 'string I type'
...and if you put this into a function then it's exactly what you want!
a.py
....
def foo():
orig_out = sys.stdout
print 'give me input: ',
sys.stdout = StringIO()
a = raw_input()
sys.stdout = orig_out
if __name__ == '__main__':
foo()
running:
yed@rublan $ ~ python a.py
give me input: something I type!!!!!
yed@rublan $ ~
|
Python scikit-learn (using grid_search.GridSearchCV)
Question: I'm using grid search to fit machine learning model parameters.
I typed in the following code (modified from the sklearn documentation page:
<http://scikit-
learn.org/stable/modules/generated/sklearn.grid_search.GridSearchCV.html>)
from sklearn import svm, grid_search, datasets, cross_validation
# getting data
iris = datasets.load_iris()
# grid of parameters
parameters = {'kernel':('linear', 'poly'), 'C':[1, 10]}
# predictive model (support vector machine)
svr = svm.SVC()
# cross validation procedure
mycv = cross_validation.StratifiedKFold(iris.target, n_folds = 2)
# grid search engine
clf = grid_search.GridSearchCV(svr, parameters, mycv)
# fitting engine
clf.fit(iris.data, iris.target)
However, when I look at `clf.estimator`, I get the following:
SVC(C=1.0, cache_size=200, class_weight=None, coef0=0.0, degree=3, gamma=0.0,
kernel='rbf', max_iter=-1, probability=False, random_state=None,
shrinking=True, tol=0.001, verbose=False)
How did I end up with a 'rbf' kernel? I didn't specify it as an option in my
parameters.
What's going on?
Thanks!
P.S. I'm using '0.15-git' version for sklearn.
**Addendum** : I noticed that `clf.best_estimator_` gives the right output. So
what is `clf.estimator` doing?
Answer: `clf.estimator` is simply a copy of the estimator passed as the first argument
to the `GridSearchCV` object. Any parameters not grid searched over are
determined by this estimator. Since you did not explicitly set any parameters
for the SVC object `svr`, it was given all default values. Therefore, because
`clf.estimator` is just a copy of `svr`, printing the value of `clf.estimator`
returns an SVC object with default parameters. Had you instead written, e.g.,
svr = svm.SVC(C=4.3)
then the value of `clf.estimator` would have been:
SVC(C=4.3, cache_size=200, class_weight=None, coef0=0.0, degree=3, gamma=0.0,
kernel='rbf', max_iter=-1, probability=False, random_state=None,
shrinking=True, tol=0.001, verbose=False)
There is no real value to the user in accessing `clf.estimator`, but then
again it wasn't meant to be a public attribute anyways (since it doesn't end
with a "_").
|
IOError: decoder jpeg not available when using Pillow
Question: Before someone says `"sudo apt-get install libjpeg-dev"` or something along
those lines, I do not have sudo access. I am on a slice of a server that does
NOT allow me to have sudo access. So I've gotta do this entire thing in my
local directory. That's the only way I can do it.
I need a python script to resize an image. It works perfectly fine for png
files, but it falls apart on jpeg files with the error listed in the title.
Here are the steps I've taken so far:
1. Downloaded `libjpeg-dev` and installed it to `$HOME/jpegtest`, so inside the jpegtest/ folder is lib/, include/, and so on
2. I downloaded `Pillow` manually and extracted it out to `$HOME/Pillow`
3. I edited the `setup.py` fild so the `JPEG_ROOT` to a `libinclude(<absolute path to jpegtest>)`
4. I built and compiled `Pillow`, where it installed to `$HOME//.pythonbrew/pythons/Python-2.7.5/lib/python2.7/site-packages/Pillow-2.4.0-py2.7-linux-x86_64.egg` The important part of the output is as follows:
*** TKINTER support not available
--- JPEG support available
*** OPENJPEG (JPEG2000) support not available
--- ZLIB (PNG/ZIP) support available
*** LIBTIFF support not available
*** FREETYPE2 support not available
*** LITTLECMS2 support not available
*** WEBP support not available
*** WEBPMUX support not available
So I would assume that this means JPEG support will function, but when I run
my program it says:
> IOError: decoder jpeg not available
While typing this I also noticed the question at [Pillow recognizes JPEG
encoder on install, but not
use](http://stackoverflow.com/questions/22409140/pillow-recognizes-jpeg-
encoder-on-install-but-not-use), which sounded very close to mine, so I tried
the solution there:
ln -s /media/sdl1/home/midnight/jpegtest/lib/libjpeg.so /media/sdl1/home/midnight/.pythonbrew/pythons/Python-2.7.5/lib
But I still have the same error.
I've been working on this problem for about two days now, and I'm not entirely
sure what to do. If anyone could offer some assistance, that would be very
helpful.
Answer: Instead of just downloading the libraries you need, try creating an entire
Python environment in locally in your home folder:
$ wget http://www.python.org/ftp/python/[desired version of Python].tgz
$ tar xzf Python[version].tgz
$ cd python-[version]
$ ./configure
$ make altinstall prefix=~ exec-prefix=~
Update your PATH variable so that your local Python is executed first:
$ PATH = /home/user/[pathtopython]:$PATH
Obtain pip, from which other packages can be installed:
$ curl https://bootstrap.pypa.io/get-pip.py > get-pip.py
$ ./get-pip.py
$ pip install pillow
URLs may vary. You might still have to modify setup.py - I haven't used this
technique with C-like libraries so I'm not sure.
|
Shared library from Boost python build does not contain any functions
Question: I'm having trouble building a shared library from my Boost Python project. For
some reason, the final shared library is nearly empty and doesn't contain any
of my wrapped functions. I've managed to get the "Hello World" example running
on my machine, so I'm pretty sure I've got Boost installed and configured
correctly.
Here is the module definition (in the FM.h header file):
/* Python Wrapper using Boost.python */
#include <boost/python.hpp>
using namespace boost::python;
BOOST_PYTHON_MODULE(fm_index)
{
class_<FM>("FM", init<>())
.def(init<uint8_t* , uint32_t, uint32_t>())
.def("save", &FM::save)
.def("count", &FM::count)
.def("locate", &FM::locate)
.def("extract", &FM::extract)
.def("load", &FM::load, return_value_policy<manage_new_object>())
.staticmethod("load")
;
}
And here is the build definition in my MakeFile:
CCP=g++
CFLAGS=-W -Wall -O3 -fPIC
INCCDS=./libcds/includes/
INCDIVSUF=./libdivsufsort/include/
BOOST_INC=/home/adevabhaktuni/boost_1_52_0/
BOOST_LIB=/home/adevabhaktuni/boost_1_52_0/stage/lib/
PYTHON_VERSION=2.6
PYTHON_INCLUDE=/usr/include/python$(PYTHON_VERSION)
FM.o: FM.cpp FM.h
$(CCP) -I $(INCCDS) -I $(INCDIVSUF) -I $(BOOST_INC) -I $(PYTHON_INCLUDE) -c $(CFLAGS) FM.cpp -o FM.o
fm_index.so: FM.o ./libcds/lib/libcds.a ./libdivsufsort/lib/libdivsufsort.a
$(CCP) -shared -W1,soname,fm_index.so -L $(BOOST_LIB) -lboost_python -lpython$(PYTHON_VERSION) FM.o ./libcds/lib/libcds.a ./libdivsufsort/lib/libdivsufsort.a -o fm_index.so
The object file FM.o is about 206 kB, and when I run nm -u on it I see all of
the functions I expect to see. However, the shared library fm_index.so is only
5 kB in size and is almost completely empty!
nm -u fm_index.so
fm_index.so:
0000000000200540 a _DYNAMIC
0000000000200728 a _GLOBAL_OFFSET_TABLE_
w _Jv_RegisterClasses
0000000000200518 d __CTOR_END__
0000000000200510 d __CTOR_LIST__
0000000000200528 d __DTOR_END__
0000000000200520 d __DTOR_LIST__
0000000000000508 r __FRAME_END__
0000000000200530 d __JCR_END__
0000000000200530 d __JCR_LIST__
0000000000200748 A __bss_start
w __cxa_finalize@@GLIBC_2.2.5
00000000000004c0 t __do_global_ctors_aux
0000000000000410 t __do_global_dtors_aux
0000000000200538 d __dso_handle
w __gmon_start__
0000000000200748 A _edata
0000000000200758 A _end
00000000000004f8 T _fini
00000000000003b8 T _init
00000000000003f0 t call_gmon_start
0000000000200750 b completed.6145
0000000000200748 b dtor_idx.6147
0000000000000490 t frame_dummy
When I try to import the fm_index module in Python, I get the following error:
ImportError: dynamic module does not define init function (initfm_index)
Does anyone know what is going on here? I'm not using bjam because I couldn't
figure out how to include the libcds.a and libdivsufsort.a libraries which the
fm_index module depends on. However, I used a similar MakeFile to the one
above on the "Hello World" project and it seemed to work fine. Any advice is
very appreciated!
Answer: You never define the functions you want to wrap with Boost.Python ?
Maybe you should take a look on the first hello world example in the
Boost.Python documentation:
[Exposing
Classes](http://www.boost.org/doc/libs/1_55_0/libs/python/doc/tutorial/doc/html/python/exposing.html)
|
Python: difficult in converting csv to list of list
Question: I want to read a .csv file which has data format like
-179.750 71.250 -26.7 -19.5 -22.5 -22.3 -8.0 -0.6 2.5
-179.750 68.750 -28.5 -21.3 -24.4 -24.4 -8.0 0.0 4.0
.....
and I want to convert to list of list as
[[-179.750,71.250..2.5],[-179.750,68.750,..4.0]
I use csv module to read csv file as:
import csv
csvfile= open('test.csv','rU')
reader = csv.reader(csvfile,quotechar=" ")
allRows = list(reader)
print allRows
The output is
[['-179.750 68.750 ... -26.5'],['-179.750 68.250 ... 4.0']]
please give me some idea so that i can modify and get my output. Thanks.
Answer: The `quotechar` argument is for the character to be used to enclose a data
entry containing delimiters, etc. You should use `delimiter`.
If you want numbers out, not lists of strings, you'll want to also put the
results through `float`.
import csv
csvfile= open('test.csv','rU')
reader = csv.reader(csvfile,delimiter=" ")
allRows = list(reader)
print allRows
numData=[ [float(i) for i in row]
for row in allRows]
print numData
|
SAWarning: Could not instantiate type <class 'sqlalchemy.sql.sqltypes.INTEGER'> when I use sqlalchemy and pd.io.sql.read_sql
Question: I try to read pandas DataFrame from my SQLite table. When I run the code below
import pandas as pd
import sqlalchemy
dbname = "sqlite:////Users/leda/home/Magnetic_stars/SQLite/Magnetic_stars.sqlite"
engine = sqlalchemy.create_engine(dbname)
res = pd.io.sql.read_sql("SELECT * FROM Resolved;", engine)
I get SAWarning:
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/sqlalchemy/dialects/sqlite/base.py:860: SAWarning: Could not instantiate type <class 'sqlalchemy.sql.sqltypes.INTEGER'> with reflected arguments [u'4']; using no arguments.
coltype = self._resolve_type_affinity(type_)
/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/sqlalchemy/dialects/sqlite/base.py:860: SAWarning: Could not instantiate type <class 'sqlalchemy.sql.sqltypes.INTEGER'> with reflected arguments [u'2']; using no arguments.
coltype = self._resolve_type_affinity(type_)
see my [issue on github](https://github.com/pydata/pandas/issues/7380) for
more details.
What am I doing wrong? Is this a bug?
Answer: Ok, so looking at [github](https://github.com/pydata/pandas/issues/7380) it
seems like your problem is solved. For the record, let me just shortly
summarize what happend.
As we know from [#7396](https://github.com/pydata/pandas/issues/7396), pandas
is introspecting _all_ the tables per _every_ read_sql_table call.
Another thing is that your database contains a table with a column of a type
reported by sqlite as "INT(4)".
SqlAlchemy (which is used by pandas under the hood) sqlite dialect [interprets
the "(4)" part as an argument to be passed to its type
constructor](https://github.com/zzzeek/sqlalchemy/blob/rel_0_9_4/lib/sqlalchemy/dialects/sqlite/base.py#L915).
But constructor of
[sqlalchemy.sql.sqltypes.INTEGER](https://github.com/zzzeek/sqlalchemy/blob/rel_0_9_4/lib/sqlalchemy/sql/sqltypes.py#L1445)
doesn't take any arguments and that [causes a
warning](https://github.com/zzzeek/sqlalchemy/blob/rel_0_9_4/lib/sqlalchemy/dialects/sqlite/base.py#L917)
and effectively ignoring these arguments, treating INT(4) as INT.
|
Why does this Python 3 code fail to remove Unicode accented characters using str.translate()?
Question: I am trying to normalise accented characters in a string in Python 3 like
this:
from bs4 import BeautifulSoup
import os
def process_markup():
#the file is utf-8 encoded
fn = os.path.join(os.path.dirname(__file__), 'src.txt') #
markup = BeautifulSoup(open(fn), from_encoding="utf-8")
for player in markup.find_all("div", class_="glossary-player"):
text = player.span.string
print(format_filename(text)) # Python console shows mangled characters not in utf-8
player.span.string.replace_with(format_filename(text))
dest = open("dest.txt", "w", encoding="utf-8")
dest.write(str(markup))
def format_filename(s):
# prepare string
s = s.strip().lower().replace(" ", "-").strip("'")
# transliterate accented characters to non-accented versions
chars_in = "àèìòùáéíóú"
chars_out = "aeiouaeiou"
no_accented_chars = str.maketrans(chars_in, chars_out)
return s.translate(no_accented_chars)
process_markup()
The input src.txt file is utf-8 encoded:
<div class="glossary-player">
<span class="gd"> Fàilte </span><span class="en"> Welcome </span>
</div>
<div class="glossary-player">
<span class="gd"> àèìòùáéíóú </span><span class="en"> aeiouaeiou </span>
</div>
The output file dest.txt looks like this:
<div class="glossary-player">
<span class="gd">fã ilte</span><span class="en"> Welcome </span>
</div>
<div class="glossary-player">
<span class="gd">ã ã¨ã¬ã²ã¹ã¡ã©ãã³ãº</span><span class="en"> aeiouaeiou </span>
</div>
and I am trying to get it to look like this:
<div class="glossary-player">
<span class="gd">failte</span><span class="en"> Welcome </span>
</div>
<div class="glossary-player">
<span class="gd">aeiouaeiou</span><span class="en"> aeiouaeiou </span>
</div>
I know there's solutions like unidecode but just wanted to find out what I'm
doing wrong here.
Answer: `chars.translate(no_accented_chars)` doesn't modify `chars`. It returns a new
string with the translation applied. If you want to use the translated string,
save it to a variable (perhaps the original `chars` variable):
chars = chars.translate(no_accented_chars)
or pass it directly to the `write` call:
dest.write(chars.translate(no_accented_chars))
|
Can't sort into categories, values will increase indefinitely, can't remove enemies
Question:
import random
from random import *
import math
from math import *
from pygame import *
import pygame, sys
from pygame.locals import *
import pygame.font
from pygame.font import *
bif= "grass.png"
mif= "character front.png"
mifB= "character back.png"
mifL= "character left.png"
mifR= "character right.png"
mifRS= "character right still.png"
mifLS= "character left still.png"
skel= "skeleton front.png"
skelB= "skeleton back.png"
skelL= "skeleton left.png"
skelR= "skeleton right.png"
swordsky="sword_sky.png"
sworddown="sword_down.png"
swordleft="sword_left.png"
swordright="sword_right.png"
swordblank="sword_blank.png"
healthpot="healthpot.png"
levelup = 1
pygame.init()
screen=pygame.display.set_mode((700,600),0,32)
#background create
r = 0
healthpotion=pygame.image.load(healthpot).convert_alpha()
sword_blank=pygame.image.load(swordblank).convert_alpha()
sword=pygame.image.load(sworddown).convert_alpha()
sword_down=pygame.image.load(sworddown).convert_alpha()
sword_sky=pygame.image.load(swordsky).convert_alpha()
sword_right=pygame.image.load(swordright).convert_alpha()
sword_left=pygame.image.load(swordleft).convert_alpha()
background=pygame.image.load(bif).convert()
character=pygame.image.load(mif).convert_alpha()
character_back=pygame.image.load(mifB).convert_alpha()
character_left=pygame.image.load(mifL).convert_alpha()
character_right=pygame.image.load(mifR).convert_alpha()
character_front=pygame.image.load(mif).convert_alpha()
character_right_still=pygame.image.load(mifRS).convert_alpha()
character_left_still=pygame.image.load(mifLS).convert_alpha()
skeleton=pygame.image.load(skel).convert_alpha()
skeleton_back=pygame.image.load(skelB).convert_alpha()
skeleton_left=pygame.image.load(skelL).convert_alpha()
skeleton_right=pygame.image.load(skelR).convert_alpha()
skeleton_front=pygame.image.load(skel).convert_alpha()
#convert image files to python useable files
x,y = 300, 250
movex,movey = 0,0
Ai_x, Ai_y = 0, 500
moveAi_x, moveAi_y=0,0
movesx, movesy=0,0
ix, iy = -500, -500
experience = 0
aihp = 15
health = 100
sx,sy = x+10, y+20
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
sys.exit()
#player movement
if event.type==KEYDOWN:
if event.key==K_a:
if character==character_right:
sx,sy= x+25, y+15
sword=sword_right
elif character==character_right_still:
sx,sy= x+25, y+15
sword=sword_right
elif character==character_left_still:
sx,sy= x-25, y+15
sword=sword_left
elif character==character_left:
sx,sy= x-25, y+15
sword=sword_left
elif character==character_front:
sx,sy= x, y+30
sword=sword_down
elif character==character_back:
sx,sy= x, y-20
sword=sword_sky
if event.key==K_RIGHT:
movex += .3
character=character_right
elif event.key==K_LEFT:
movex -= .3
character=character_left
elif event.key==K_UP:
movey -= .3
character=character_back
elif event.key==K_DOWN:
movey += .3
character=character_front
if event.type==KEYUP:
if event.key==K_RIGHT:
movex = 0
character=character_right_still
elif event.key==K_LEFT:
movex = 0
character=character_left_still
elif event.key==K_UP:
movey = 0
character=character_back
elif event.key==K_DOWN:
movey = 0
character=character_front
if event.key==K_a:
if character==character_right:
sx,sy= x+25, y+15
sword=sword_blank
elif character==character_right_still:
sx,sy= x+25, y+15
sword=sword_blank
elif character==character_left_still:
sx,sy= x-25, y+15
sword=sword_blank
elif character==character_left:
sx,sy= x-25, y+15
sword=sword_blank
elif character==character_front:
sx,sy= x, y+30
sword=sword_blank
elif character==character_back:
sx,sy= x, y-20
sword=sword_blank
x+=movex
y+=movey
#Creep movement
sdist = sqrt((sx - Ai_x)**2 + (sy - Ai_y)**2)
#damage
y2 = y - 20
if (sx, sy) != (x+40,y2):
if x > sx:
movesx = +.3
if x < sx:
movesx = -.3
if y > sy:
movesy = +.3
if y < sy:
movesy = -.3
sx+=movesx
sy+=movesy
#sword movement
if (Ai_x, Ai_y) != (x,y):
if x > Ai_x:
moveAi_x = .2
if x < Ai_x:
moveAi_x = -.2
if y > Ai_y:
moveAi_y = +.2
if y < Ai_y:
moveAi_y = -.2
Ai_x+=moveAi_x
Ai_y+=moveAi_y
#creep movement
#Controls for character
newallocatedstr=0
newallocatedend=0
newallocatedagi=0
newallocatedchr=0
newallocatedwis=0
#stats
if levelup == 2:
newallocatedstr = eval(input("strength? (0-5):" ))
newallocatedend = eval(input("endurance? (0-5):" ))
newallocatedagi= eval(input(" agility? (0-5):" ))
newallocatedchr = eval(input(" charisma? (0-5):" ))
newallocatedwis = eval(input("wisdom? (0-5):" ))
if ((newallocatedstr + newallocatedend)
+ (newallocatedagi + newallocatedchr) + newallocatedwis) > 5:
print("You filthy cheater.")
pygame.quit()
sys.exit()
levelup = 1
#levelup
strn = newallocatedstr
end = newallocatedend
agi = newallocatedagi
chra = newallocatedchr
wis = newallocatedwis
endurance= 5 + end
strength=5 + strn
wisdom=5 + wis
charisma=5 + chra
agility=5 + agi
#stats
# render health text
maxhealth = health
health = maxhealth
if sdist<12:
aihp = aihp - 1
dist = sqrt((Ai_x - x)**2 + (Ai_y - y)**2)
#damage
if dist<6:
health = health - 1
font = pygame.font.Font(None, 25)
mytext = font.render("Health:{0}".format(health), 1, (255,255,255))
exp = font.render("Experience:{0}".format(experience), 1, (255,255,255))
mytext = mytext.convert_alpha()
if health == 0:
print("Game over")
pygame.quit()
sys.exit()
mana = 50 + wisdom
font = pygame.font.Font(None, 25)
mana = font.render("Mana:"+str(mana), 1, (255,255,255))
font = pygame.font.Font(None, 20)
aihealth = font.render("Ai Health:{0}".format(aihp), 1, (255,255,255))
#create background
screen.blit(background, (0,0))
if aihp >= 0:
screen.blit(skeleton, (Ai_x, Ai_y))
screen.blit(aihealth, (Ai_x-25, Ai_y+40))
else:
experience = experience + 10
screen.blit(exp, (15, 5))
screen.blit(mytext, (15, 25))
screen.blit(mana, (15, 50))
screen.blit(aihealth, (Ai_x-25, Ai_y+40))
screen.blit(sword, (sx, sy))
screen.blit(healthpotion, (ix, iy))
screen.blit(character, (x,y))
pygame.display.flip()
pygame.display.update()
This is my current code, ive been working on it for a while.
Obviously the images won't work for anyone testing it, but my current problem
is, when an enemy's `hp` goes below ``0, I don't know how to make the enemy
completely get removed. I tried to do an
if AIhp <= 0:
Ai_x, Ai_y = -50, -50
But that only removes it from the screen, and since I also want to add drops
it means when the Ai coordinates change so does the drop item coordinates
since I only know how to make the drop coordinates equal to AI coordinates if
I want it to appear in the place the AI died.
Also the exp, and health both go down fine, but when I try to add exp from
monster kill it goes up by about 10 a millisecond indefinitely, and when I
tried to make the `maxhealth = health + endurance` it was same issue with
growing indefinitely.
I really need help, I have tried sorting my code into multiple functions but
it only makes the entire thing stop working which pretty much exits out the
option of just changing the sprites to objects...
Answer: Your code does not take into account, that an enemy cannot be dead. I
recommend to use a list of enemies, and then do all the operations for all the
enemies. On enemy death, you will add the xp only once.
It's better do make an Enemy class, that will do all the drawing, killing,
etc, so you will not need to worry about it in your main code. Here are
example calls:
for enemy in enemies:
if sdist<12:
enemy.hit()
if not enemy.isAlive():
enemies.remove(enemy)
#add Drops
enemy.move()
enemy.draw(screen)
Same goes for a player. If you divide this up, you will have a much easier
time adding new functionality. The whole player movement could be a function
in the class Player, since it does not interact with anything else.
Do not use eval, a player would be able to execute any code. You want to cast
the str to int. Like this:
newallocatedwis = int(input("wisdom? (0-5):" ))
If changing the code is too difficult, you can always start over. You already
have the code written, so you will know what goes where.
|
Split a huge CSV in three random files in Python
Question: I have a huge CSV and I want to split it in 3 random files with almost* equal
size.
*almost: the size cannot be divided by 3
I was thinking to create 3 blank lists, then in a for loop, I would randomly
choose one number between `range(0,len(mycsv))` and append it in each list.
Then, I will create a csv with the files from the first list and go on. But I
think that this will be slow enough. Is there any build-in way or an easier
than my own?
Answer: For each line of your csv, randomly insert this line in one of three blank csv
files. For 100.000 lines, it should not take long.
import random
with open("mycsv.csv") as fr:
with open("1.csv", "w") as f1, open("2.csv", "w") as f2, open("3.csv", "w") as f3:
for line in fr.readlines():
rd = random.randint(1, 3)
f = f1 if rd == 1 else (f2 if rd == 2 else f3)
f.write(line)
|
"self" as method attribute
Question: I am attempting to teach myself Python at the moment and I am trying to work
my way through a python program, which is essentially a pacman game. Whilst
doing so, I discovered the following class call which contains 'self' as a
method attribute.
game = Game(agents, display, self, catchExceptions=catchExceptions)
THE CONTEXT:
This method call is part of the following function:
class ClassicGameRules:
"""
These game rules manage the control flow of a game, deciding when
and how the game starts and ends.
"""
def __init__(self, timeout=30):
self.timeout = timeout
def newGame( self, layout, pacmanAgent, ghostAgents, display, quiet = False, catchExceptions=False):
[1] agents = [pacmanAgent] + ghostAgents[:layout.getNumGhosts()]
[2] initState = GameState()
[3] initState.initialize( layout, len(ghostAgents) )
[4] game = Game(agents, display, self, catchExceptions=catchExceptions)
[5] game.state = initState
[6] self.initialState = initState.deepCopy()
[1] Just to make this a little more palatable, 'agents' contain the pacman and
ghost agent objects combined into a list of lists, which when printed looks
something like this:
[<keyboardAgents.KeyboardAgent instance at 0x1004fe758>, <ghostAgents.RandomGhost instance at 0x1004fe518>, <ghostAgents.RandomGhost instance at 0x1004fe7a0>, <ghostAgents.RandomGhost instance at 0x1004fe950>, <ghostAgents.RandomGhost instance at 0x1004feb90>]
[2] initState = GameState(): GameState() is a data object containing all sorts
of information about the Game state
[3] initState.initialize( layout, len(ghostAgents) ): initialises the very
first game state from a layout array. This layout array lets the program know
where the pacman and ghosts spawn, where the food and capsules are displayed
and where walls can be found.
[4] game = Game(agents, display, self, catchExceptions=catchExceptions): The
Game class manages the control flow, soliciting actions from agents. Agents
can be a keyboard agent (controlled by the player, who controls the pacman)
and automated agents controlling the ghosts (see [1]).
[5] game.state = initState: copies the content of [2] into the variable
game.state.
[6] self.initialState = initState.deepCopy(): deepCopy is a function which
runs a copy operation on variables which define the game state of the game
board, such as the layout or the position of the food.
CLASS GAME: Here is the code of the class Game:
class Game:
"""
The Game manages the control flow, soliciting actions from agents.
"""
def __init__( self, agents, display, rules, startingIndex=0, muteAgents=False, catchExceptions=False ):
self.agentCrashed = False
self.agents = agents ## agents contain the pacman and ghost agent objects combigned into a list of lists agents = [pacmanAgent] + ghostAgents[:layout.getNumGhosts()]
self.display = display
#print("This is the display object" + str(self.display))
self.rules = rules ## The rules are passed on as the self attribute of the ClassicGameRules class within the call of Game in newGame [REF 115].
self.startingIndex = startingIndex ## starting index is given as default attribute by the __init__ method.
self.gameOver = False
self.muteAgents = muteAgents
self.catchExceptions = catchExceptions
self.moveHistory = []
self.totalAgentTimes = [0 for agent in agents] ## This creates a list that replaces the list elements of the agents list, which contains the agent objects, with zeros. It looks something like this [0,0,0]
##print(self.totalAgentTimes)
self.totalAgentTimeWarnings = [0 for agent in agents]
self.agentTimeout = False
import cStringIO
self.agentOutput = [cStringIO.StringIO() for agent in agents]
WHAT CONFUSES ME
When game = Game(agents, display, self, catchExceptions=catchExceptions) is
called, "self' is passed on to Game as an attribute. In Game the data
contained within "self" takes is placed within the "rules" variable.
But does does this variable contain?
Intuitively I would suggest that it would be the "self" instance of the
newGame object. But seeing how this method is called self.initialState =
initState.deepCopy(), which doesn't seem to make sense...
Or are we referencing the self - object of the ClassicGameRules class?
I know this was a handful of text to read, but I wasn't quite sure how to
shorten this question. Please let me know if more information is required. Any
help would be highly appreciated. :)
Z_101
Answer: In the method `newGame` of the class `ClassicGameRules`, `self` represents the
current instance of the class:
game = Game( agents, display, self, ...)
v v v
def __init__(self, agents, display, rules, ...)
The first `self` of the `__init__` method here is to represents to the new
object that will be created in the `Game` class.
In your case, the `Game` class has in `rules` a reference to the instance of
`ClassicGameRules` which called the constructor of the `Game` instance. The
`deepCopy` after has nothing to do and is just to synchronized the initial
state of both objects, by coping the state of the object just created (`game`)
into the "parent" object (instance of `ClassicGameRules`).
|
How to get a list of axes for a figure in pyplot?
Question: I am new to `python` and `pyplot`. I am trying to understand the documentation
for the Matplotlib API related to the Figure [Figure
API](http://matplotlib.org/api/figure_api.html).
In the beginning it says there is a `class matplotlib.figure.AxesStack`, and
then
> The AxesStack is a callable, where ax_stack() returns the current axes
When I try to use this in a program
import numpy as np
import matplotlib.pyplot as plt
n=4
v=np.arange(n)
X,Y = np.meshgrid(v,v)
Z=np.random.rand(n-1,n-1)
fig, ax = plt.subplots()
plt.pcolormesh(X, Y, Z)
plt.axis('tight')
plt.colorbar()
ast=fig.ax_stack()
plt.show()
I get error
AttributeError: 'Figure' object has no attribute 'ax_stack'
Answer: The property `axes` returns a list of the `Axes` objects in the `Figure`
object:
ax_list = fig.axes
([doc](http://matplotlib.org/api/figure_api.html#matplotlib.figure.Figure.axes))
|
3D volume acrobatics in python.. selecting x/y/z rows/columns in 3D numpy arrays
Question: I'm new to ndarrays in Numpy, so please be kind. I have a 3D raw volume
imported into numpy as a dtype uint8 array with shape `(309L, 138L, 134L)`
representing Z, Y, X dimensions.
The Raw image dimensions are (x,y,z), 134 138 309
This array is called `ThreeD`.
I can plot a Z 'section' of dimension XY of ThreeD with
ThreeD[70]
(selecting row 70)
I can plot a Y 'section' of dimension XZ of ThreeD with
ThreeD[:,70]
(selecting column 70)
but of course, there is the extra dimension! These first two are easy to
reference, but I'm at a loss of how to select/reference the third dimension..
i.e. the X section of dimension YZ (i.e. slicing a face of the matrix). I
should add that I'm not entirely sure of the XZ/YZ dimension here, so those
references might be reversed.
I got as far as I did using Sebastian Raschka's handy cheat sheet
<http://sebastianraschka.com/Articles/2014_matrix_cheatsheet.html>
thanks kindly for any help
Answer: `ThreeD[70]` for `Z`
`ThreeD[:, 70]` for `Y`
`ThreeD[:, :, 70]` or `ThreeD[..., 70]` for `X`
from Jaime. Thankyou.
|
Python Pandas calucate Z score of groupby means
Question: I have a dataframe like this:
df = pd.DataFrame({'Year' : ['2010', '2010', '2010', '2010', '2010', '2011', '2011', '2011', '2011', '2011', '2012', '2012', '2012', '2012', '2012'],
'Name' : ['Bob', 'Joe', 'Bill', 'Bob', 'Joe', 'Dave', 'Bob', 'Joe', 'Bill', 'Bill', 'Joe', 'Dave', 'Dave', 'Joe', 'Steve'],
'Score' : [95, 76, 77, 85, 82, 92, 67, 80, 77, 79, 82, 92, 64, 71, 83]})
I would like to get the Z Score for each _Name_ in each _Year_.
I can do it if subset the Year column like this:
(df[df.Year == '2010'].groupby(['Year', 'Name'])['Score'].mean() - df[df.Year == '2010'].groupby(['Year', 'Name'])['Score'].mean().mean()) / ( df[df.Year == '2010'].groupby(['Year', 'Name'])['Score'].mean().std())
Is there a cleaner way of doing it?
Answer: There is a `zscore` functionality in `scipy`, but be careful the default
delta-degree-of-freedom is 0 in `scipy.stats.zscore`:
In [171]:
import scipy.stats as ss
S=(df[df.Year == '2010'].groupby(['Year', 'Name'])['Score'].mean())
pd.Series(ss.zscore(s, ddof=1), S.index)
Out[171]:
Year Name
2010 Bill -0.714286
Bob 1.142857
Joe -0.428571
dtype: float64
|
In PyGame, how to move an image every 3 seconds without using the sleep function?
Question: Recently I've learned some basic Python, so I am writing a game using PyGame
to enhance my programming skills.
In my game, I want to move an image of a monster every 3 seconds, at the same
time I can aim it with my mouse and click the mouse to shoot it.
At the beginning I tried to use **time.sleep(3)** , but it turned out that it
pause the whole program, and I can't click to shoot the monster during the 3
seconds.
So do you have any solution for this?
Thanks in advance! :)
* * *
Finally I solved the problem with the help of you guys. Thank you so much!
Here is part of my code:
import random, pygame, time
x = 0
t = time.time()
while True:
screen = pygame.display.set_mode((1200,640))
screen.blit(bg,(0,0))
if time.time() > t + 3:
x = random.randrange(0,1050)
t = time.time()
screen.blit(angel,(x,150))
pygame.display.flip()
Answer: Pygame has a clock class that can be used instead of the python time module.
Here is an example usage:
clock = pygame.time.Clock()
time_counter = 0
while True:
time_counter = clock.tick()
if time_counter > 3000:
enemy.move()
time_counter = 0
|
Python regex matching pattern not surrounded by double quotes
Question: I'm not comfortable with regex, so I need your help with this one, which seems
tricky to me.
Let's say I've got the following string :
string = 'keyword1 keyword2 title:hello title:world "title:quoted" keyword3'
What would be the regex to get `title:hello`, `title:world`, remove these
strings from the original one and leave `"title:quoted"` in it, because it's
surrounded by double quotes ?
I've already seen [this similar SO
answer](http://stackoverflow.com/questions/11792258/python-regex-to-replace-a-
string-if-not-surrounded-by-single-quotes), and here is what I ended up with :
import re
string = 'keyword1 keyword2 title:hello title:world "title:quoted" keyword3'
def replace(m):
if m.group(1) is None:
return m.group()
return m.group().replace(m.group(1), "")
regex = r'\"[^\"]title:[^\s]+\"|([^\"]*)'
cleaned_string = re.sub(regex, replace, string)
assert cleaned_string == 'keyword1 keyword2 "title:quoted" keyword3'
Of course, it does not work, and I'm not surprised, because regex are esoteric
to me.
Thank you for your help !
# Final solution
Thanks to your answers, here is the final solution, working for my needs :
import re
matches = []
def replace(m):
matches.append(m.group())
return ""
string = 'keyword1 keyword2 title:hello title:world "title:quoted" keyword3'
regex = '(?<!")title:[^\s]+(?!")'
cleaned_string = re.sub(regex, replace, string)
# remove extra withespaces
cleaned_string = ' '.join(cleaned_string.split())
assert cleaned_string == 'keyword1 keyword2 "title:quoted" keyword3'
assert matches[0] == "title:hello"
assert matches[1] == "title:world"
Answer: You can check for word boundaries (`\b`):
>>> s = 'keyword1 keyword2 title:hello title:world "title:quoted" keyword3'
>>> re.sub(r'\btitle:\w+\b', '', s, re.I)
'keyword1 keyword2 "title:quoted" keyword3'
Or, alternatively, you can use [negative look behind and ahead
assertions](https://docs.python.org/2/library/re.html#regular-expression-
syntax) to check for not having quotes around `title:\w+`:
>>> re.sub(r'(?<!")title:\w+(?!")', '', s)
'keyword1 keyword2 "title:quoted" keyword3'
|
Why does Python run a C++ function faster than C++ running its own function via its main() function?
Question: I wrote an extremely brute force function to check if a number is a prime
number. The loop goes up to 1,000,000. I compiled that C++ code into a shared
library and ran that function with Python, then I ran the same function within
C++'s main() function. Why does time show that python did it faster than C++?
My C++ Code (cppcode.cpp):
#include <iostream>
#include <boost/python.hpp>
using namespace boost::python;
bool isPrime(long number) {
if(number == 2) {
return true;
}
for(int i = 3; i < number; i++) {
if(number % i == 0) {
return false;
}
}
return true;
}
void runcpp(void) {
for(int i = 2; i < 1000000; i++) {
if(isPrime(i)) {
std::cout << i << " is a prime number!" << std::endl;
}
}
}
BOOST_PYTHON_MODULE(cppcode)
{
def("runcpp", runcpp);
}
int main() {
runcpp();
return 0;
}
My Python Code (main.py):
import cppcode
if __name__ == "__main__":
cppcode.runcpp()
Shell Output:
$ g++ -Wall -shared -fPIC cppcode.cpp -o cppcode.so -lpython2.7 -lboost_python -I/usr/include/python2.7/
$ g++ -Wall cppcode.cpp -o main -lpython2.7 -lboost_python -I/usr/include/python2.7/
$ (time python main.py >> time.txt) && (time ./main >> time.txt)
real 10m26.519s
user 10m25.042s
sys 0m0.737s
real 10m48.754s
user 10m47.796s
sys 0m0.763s
As you can see from the shell output above, when python ran the C++ "runcpp"
function, it ran ~20 seconds faster than when C++'s main() function ran the
same "runcpp" function. Does anyone have any idea as to why Python executed
the same function faster than C++? Or am I reading it wrong?
Answer: Remove all print statements - these cause the program to pause and you're
benchmarking the time your system spends doing I/O which is highly variable
and blankets any differences between your Python and your pure C++ runtime.
Try doing some heavy mathematical computation like finding the first 1000
primes for a more fair comparison.
Having said that, I don't expect your C++ program to outperform your Python
program by much if at all. They should be neck-to-neck for the most part with
the only possible disadvantage for Python being its interpreter's "boot-up"
time.
|
Color image segmentation with Python
Question: I have many pictures as below: 
My objective is to identify those "beads", try to mark it with a circle, and
count the detected numbers.
I tried to use image segmentation algorithms via Python and the source codes
are as below:
from matplotlib import pyplot as plt
from skimage import data
from skimage.feature import blob_dog, blob_log, blob_doh
from math import sqrt
from skimage.color import rgb2gray
from scipy import misc # try
image = misc.imread('test.jpg')
image_gray = rgb2gray(image)
blobs_log = blob_log(image_gray, max_sigma=10, num_sigma=5, threshold=.1)
# Compute radii in the 3rd column.
blobs_log[:, 2] = blobs_log[:, 2] * sqrt(2)
blobs_dog = blob_dog(image_gray, max_sigma=2, threshold=.051)
blobs_dog[:, 2] = blobs_dog[:, 2] * sqrt(2)
blobs_doh = blob_doh(image_gray, max_sigma=2, threshold=.01)
blobs_list = [blobs_log, blobs_dog, blobs_doh]
colors = ['yellow', 'lime', 'red']
titles = ['Laplacian of Gaussian', 'Difference of Gaussian',
'Determinant of Hessian']
sequence = zip(blobs_list, colors, titles)
for blobs, color, title in sequence:
fig, ax = plt.subplots(1, 1)
ax.set_title(title)
ax.imshow(image, interpolation='nearest')
for blob in blobs:
y, x, r = blob
c = plt.Circle((x, y), r, color=color, linewidth=2, fill=False)
ax.add_patch(c)
plt.show()
The best results obtained so far are still unsatisfactory: 
How can I improve it ?
Answer: You could use Gimp or Photoshop and test some filters and colors changes to
differentiate the circles from the background. Brightness and Contrast
adjustments may work. Then you can apply an Edge detector to detect the
circles.
|
Running A Process In the Background In Flask
Question: I am making a webapp in python and flask which will email & tweet to the
webmaster when the moment his website goes down. I am thinking of running an
infinite while loop which waits for 10 minutes and then send a request to the
website to be checked and checks if the returned response is 200. The problem
is that were in the script can I insert this loop? Any suggestions about how I
can achieve this?
Answer: # Soldier, tell me when you are dead
Trying to report a problem from dying app is not the most reliable method.
# Use external process to watch the app
You shall have some external independent app, monitoring your app.
If you live in pure Python environment, you may write a script, which will
check if accessing some app url succeeds and if not, it would alert someone.
For alerting, you may try e.g. `logbook` with log records being sent by e-mail
(see
[MailHandler](http://pythonhosted.org/Logbook/api/handlers.html#logbook.MailHandler)
or
[GMailHandler](http://pythonhosted.org/Logbook/api/handlers.html#logbook.GMailHandler)).
In production environment it would be best to run some monitoring app like
[Nagios](http://www.nagios.org/about) and simply check by
[`check_http`](https://www.monitoring-plugins.org/doc/man/check_http.html)
# Sample checking script using Logbook
For better readibility, the content is split to more parts, real script is in
one file called `monitor_url.py`
## `monitor_url.py`: Docstring, imports and MAIL_TEMPLATE
Docstring explains usage and is finally used by command line parser `docopt`
Imports are mostly `logbook` related
"""monitor_url.py - check GET access to a url, notify by GMail about problems
Usage:
monitor_url.py [options] <url> <from> <pswd> <to>...
monitor_url.py -h
Options:
-L, --logfile <logfile> Name of logfile to write to [default: monitor_url.log].
-N, --archives <archives> Number of daily logs to keep, use 0 for unlimited [default: 0]
The check is performed once a minute and does HTTP GET request to <url>.
If there is a problem, it sends an e-mail using GMail account.
There is a limit of 6 e-mails, which can be sent per hour.
"""
import time
from logbook import Logger, GMailHandler, StderrHandler, NestedSetup, TimedRotatingFileHandler, Processor
from logbook.more import JinjaFormatter
from datetime import timedelta
import requests
from requests.exceptions import ConnectionError
MAIL_TEMPL = """Subject: {{ record.level_name }} on {{ record.extra.url }}
{{ record.message }}
Url: {{ record.extra.url }}
{% if record.exc_info %}
Exception: {{ record.formatted_exception }}
{% else %}
Status: {{ record.extra.req.status_code }}
Reason: {{ record.extra.req.reason }}
{% endif %}
"""
## `monitor_url.py`: `main` function performing the checks
This script is looping in `while` and performs once a minute a check. If a
problem is detected, or status code has changed, GMailHandler is configured to
send e-mail.
def main(url, e_from, pswd, e_to, logfile, archives):
log = Logger("httpWatcher")
def inject_req(record):
record.extra.url = url
record.extra.req = req
processor = Processor(inject_req)
gmail_handler = GMailHandler(e_from, pswd, e_to,
level="WARNING", record_limit=6, record_delta=timedelta(hours=1), bubble=True)
gmail_handler.formatter = JinjaFormatter(MAIL_TEMPL)
setup = NestedSetup([StderrHandler(),
TimedRotatingFileHandler(logfile, bubble=True),
gmail_handler,
processor])
with setup.applicationbound():
last_status = 200
while True:
try:
req = requests.get(url)
if req.status_code != last_status:
log.warn("url was reached, status has changed")
if req.ok:
log.info("url was reached, status OK")
else:
log.error("Problem to reach the url")
last_status = req.status_code
except ConnectionError:
req = None
log.exception("Unable to connect")
last_status = 0
time.sleep(6)
## `montior_url.py` final `if __name__ ...`
This part actually parses command line parameters and calls the `main`
if __name__ == "__main__":
from docopt import docopt
args = docopt(__doc__)
print args
main(args["<url>"], args["<from>"], args["<pswd>"], args["<to>"], args["--logfile"],
int(args["--archives"]))
## Call it
Try to call it without parameters:
$ python monitor_url.py
Usage: monitor_url.py [options] ... monitor_url.py -h
To get full help, use `-h`
$ python monitor_url.py -h
...the help is the same as script docstring...
Use it for real monitoring, here used for monitoring `http://localhost:8000`
$ python monitor_url.py -L mylog.log -N 2 http://localhost:8000 <yourmail>@gmail.com xxxpasswordxxx [email protected]
{'--archives': '2',
'--logfile': 'mylog.log',
'-h': False,
'<from>': '[email protected]',
'<pswd>': 'xxxxxxx',
'<to>': ['[email protected]'],
'<url>': 'http://localhost:8000'}
[2014-06-09 19:41] INFO: httpWatcher: url was reached, status OK
[2014-06-09 19:41] ERROR: httpWatcher: Unable to connect
Traceback (most recent call last):
....(shortened)...
raise ConnectionError(e, request=request)
ConnectionError: HTTPConnectionPool(host='localhost', port=8000): Max retries exceeded with url: / (Caused by <class 'socket.error'>: [Errno 111] Connection refused)
[2014-06-09 19:41] WARNING: httpWatcher: url was reached, status has changed
[2014-06-09 19:41] INFO: httpWatcher: url was reached, status OK
Check logfile created in local folder.
Check your gmail inbox (if there is nothing, you have to play with the
password).
# Conclusions
Twitter notification is also possible with `logbook`, but is not shown here.
To run the script, Python 2.7 is expected and you shall install some packages:
$ pip install logbook jinja2 requests
Managing notification from such a script is not easy. Consider this script of
beta quality in this regard.
Usage of solutions like `Nagios` seems to be more appropriate for this
purpose.
|
How to automatically cluster my dataset images into different groups based on local features or global using python or OpenCV?
Question: I have a dataset of images , and i want to group my images into different
groups based on content. What i have tried till now is find median of images
and thought to group them into different clusters based on median values , How
can i do that? This is what i have tried till now. How can i do cluster my
images into groups? I did Google out many things on clustering, But it showed
results on clustering based on colors rather than clustering images into
groups.Can anyone provide me with informative answers?Can i automatically
cluster my dataset into groups based on median or some other technique?
from PIL import Image
import numpy as np
import os
Median=[]
k=[]
def get_imlist(path):
return [os.path.join(path,f) for f in os.listdir(path) if f.endswith('.jpg')]
path='D:/Images/dataset'
imlist= get_imlist(path)
for file in imlist:
head,tail=os.path.split(file)
im=np.array(Image.open(file).convert('L'))
m=np.median(im)
M=[m,tail]
print '.'
Median.append(M)
Results=sorted(Median, key=lambda median: median[0])
print Results
Answer: k-means is a common method for clustering and is in OpenCV
<http://docs.opencv.org/modules/core/doc/clustering.html>.
Before you cluster it is recommended that you use a representation that has a
lower number of dimensions than the full n*m set of pixels. This is for two
main reasons, robustness to noise, and the reduction of computational cost of
the clustering process. The choice of representation may be critical to the
perceived quality of the clusters, and will largely depend on your
application. My current favorite is the GIST descriptor (c++:
<http://lear.inrialpes.fr/software>, matlab:
<http://people.csail.mit.edu/torralba/code/spatialenvelope/>). However that is
not in OpenCV. So here i will use a gray level histogram, thus reducing the
dimensions from m*n to b = no. of bins.
Assuming a vector of gray level input images named frames.
//set up histogram
int histSize = 128;
float range[] = { 0, histSize } ;
const float* histRange = { range };
bool uniform = true; bool accumulate = false;
Mat_<float> dataHists;
cv::Mat grayImg;
Mat hist_i;
for(int i=0; i <frames.size(); i++)
{
grayImg =frames[i];
//histogram gray image
calcHist( &grayImg, 1, 0, Mat(), hist_i, 1, &histSize, &histRange, uniform, accumulate );
normalize(hist_i, hist_i, 0, hist_i.rows, NORM_MINMAX, -1, Mat() );
//transpose for feature vector
hist_i = hist_i.t();
//add to feature vectors for k-means
dataHists.push_back(cv::Mat(hist_i));
}
//k-means
int k = 100;
cv::Mat bestLabels;
cv::kmeans(dataHists,k,bestLabels,TermCriteria(),3,KMEANS_PP_CENTERS);
//have a look
vector<cv::Mat> clusterViz(bestLabels.rows);
for(int i=0;i<bestLabels.rows; i++)
{
clusterViz[bestLabels.at<int>(i)].push_back(cv::Mat(frames[bestLabels.at<int>(i)]));
}
namedWindow("clusters", WINDOW_NORMAL );
for(int i=0;i<clusterViz.size(); i++)
{
cv::imshow("clusters",clusterViz[i]);
cv::waitKey();
}
Hope this helps you.
|
Compare specific fields in two files -Python
Question: I want to compare two files(file1 and file2) with different columns but have
the first 4 columns in common, the output should be the lines of file2
existing in file1:
**file 1:**
132.227.127.170 49163 173.194.40.110 443
132.227.127.170 49164 31.13.86.65 443
132.227.127.170 49165 193.51.224.40 443
132.227.127.170 49166 193.51.224.40 443
132.227.127.170 49167 193.51.224.40 443
......
**file 2:**
132.227.127.170 49155 17.172.232.150 5223 3 4500.1587 106
132.227.127.170 49155 17.172.232.150 5223 3 8100.3275 106
132.227.127.170 49163 173.194.40.110 443 5 0.405 53
132.227.127.170 49164 31.13.86.65 443 7 0.018600000000000002 53
132.227.127.170 49165 193.51.224.40 443 417 42.5117 32362
132.227.127.170 49166 193.51.224.40 443 34 33.382 1236
132.227.127.170 49167 193.51.224.40 443 8 37.067099999999996 458
132.227.127.170 49168 193.51.224.40 443 5 0.0008 53
132.227.127.170 49169 193.51.224.40 443 5 0.0009 53
132.227.127.170 49170 31.13.86.65 443 937 30.7529 117540
......
**Output:**
132.227.127.170 49163 173.194.40.110 443 5 0.405 53
132.227.127.170 49164 31.13.86.65 443 7 0.018600000000000002 53
132.227.127.170 49165 193.51.224.40 443 417 42.5117 32362
132.227.127.170 49166 193.51.224.40 443 34 33.382 1236
132.227.127.170 49167 193.51.224.40 443 8 37.067099999999996 458
....
So I tried this code, it normally HAS to work, I already tried it in other
cases and worked very well, but I don t know what went wrong this time !!
import string
tstFile1=open("output","w+")
with open('file1') as file1, open('file2') as file2:
myf=[line.strip().split() for line in file1]
f1=[line.strip() for line in filter(lambda x: x.strip().split()[0:3] in myf, file2)]
for i in f1:
tstFile1.write("%s\n" %i)
tstFile1.close()
So what do you suggest me to change in it? ANY help pleaase I tried to use an
AWK command, but still the same problem
Answer: The problem is that you are trying to be too fancy. There are too many steps
in one, so you can easily miss small detail.
The file1 contains 4 columns, but you are only extracting the first 3 columns
from file2.
Your problem will be fixed if you change the following row:
f1=[line.strip() for line in filter(lambda x: x.strip().split()[0:4] in myf, file2)]
and
f2=[line.strip() for line in filter(lambda x: x.strip().split()[0:4] not in myf, file2)]
Changing [0:3] to [0:4] (remember that python indexes are _between_ elements)
But please split up this logic, it will make debugging **much** easier!
|
How to plot a density map in python?
Question: I have a .txt file containing the x,y values of regularly spaced points in a
2D map, the 3rd coordinate being the density at that point.
4.882812500000000E-004 4.882812500000000E-004 0.9072267
1.464843750000000E-003 4.882812500000000E-004 1.405174
2.441406250000000E-003 4.882812500000000E-004 24.32851
3.417968750000000E-003 4.882812500000000E-004 101.4136
4.394531250000000E-003 4.882812500000000E-004 199.1388
5.371093750000000E-003 4.882812500000000E-004 1278.898
6.347656250000000E-003 4.882812500000000E-004 1636.955
7.324218750000000E-003 4.882812500000000E-004 1504.590
8.300781250000000E-003 4.882812500000000E-004 814.6337
9.277343750000000E-003 4.882812500000000E-004 273.8610
When I plot this density map in gnuplot, with the following commands:
set palette rgbformulae 34,35,0
set size square
set pm3d map
splot "dens_map.map" u 1:2:(log10($3+10.)) title "Density map"`
Which gives me this beautiful image:
Now I would like to have the same result with matplotlib.
Answer: Here is my aim at a more complete answer including choosing the color map and
a logarithmic normalization of the color axis.
import matplotlib.pyplot as plt
import matplotlib.cm as cm
from matplotlib.colors import LogNorm
import numpy as np
x, y, z = np.loadtxt('data.txt', unpack=True)
N = int(len(z)**.5)
z = z.reshape(N, N)
plt.imshow(z+10, extent=(np.amin(x), np.amax(x), np.amin(y), np.amax(y)),
cmap=cm.hot, norm=LogNorm())
plt.colorbar()
plt.show()
I assume here that your data can be transformed into a 2d array by a simple
reshape. If this is not the case than you need to work a bit harder on getting
the data in this form. Using imshow and not pcolormesh is more efficient here
if you data lies on a grid (as it seems to do). The above code snippet results
in the following image, that comes pretty close to what you wanted:
|
How to show webcam capture in Plone site using OpenCV?
Question: I am using Plone 4.3. I am trying to create a face recognition system on the
Plone site. I need to show webcam captures using a template page. My sample
code is below. However, when I run this code, I can't get the captured image
in the template file.
sample.py:
class video(BrowserView):
video=ViewPageTemplateFile('video.pt')
def chow(self):
return self.video()
def show_video(self):
import cv2.cv as cv
cv.NamedWindow("camera", 1)
capture = cv.CaptureFromCAM(0)
while True:
img = cv.QueryFrame(capture)
return img
video.pt:
<div id="res">
<!--Here face is url name-->
<img id="draw" tal:attributes="src python:context.absolute_url() + '/face'">
<!--the above line refers to call a method of show_video()-->
</div>
Answer: This is a good starting point:
<http://plone.org/products/collective.takeaportrait> (activate the optional
OpenCV integration).
Keep in mind that there's a **big** difference between showing the camera
output on the screen (that is simply HTML 5) and performing face recognition
server side.
|
Adding more than one list
Question: I want to try the many ways the function of python So, I want to not use zip
use other python function ,how can i do to?
this is use zip and adding more than one list: but i want to other way not use
zip:
x = [12, 22, 32, 42, 52, 62, 72, 82, 29]
y = [10, 11, 12, 13, 14, 15, 16, 17, 18]
def add_list(i, j):
l = []
for n, m in zip(x, y):
l.append(n + m)
return l
i know this way,
Answer: **without** using `zip`, you can use `map`:
from operator import add
x = [12, 22, 32, 42, 52, 62, 72, 82, 29]
y = [10, 11, 12, 13, 14, 15, 16, 17, 18]
res = map(add, x, y)
# [22, 33, 44, 55, 66, 77, 88, 99, 47]
Note that if the iterables are of different lengths, than the shortest will be
padded with `None` which will cause a `TypeError` in the `add` instead of
`zip` which will truncate to the shortest list.
**On an aside** there's absolutely nothing wrong with using `zip` \- I'd
probably re-write it as a list-comp though, eg:
[sum(items) for items in zip(x, y)]
This then scales easily to doing `zip(x, y, z, another_list)` etc...
|
pandas ValueError: numpy.dtype has the wrong size, try recompiling
Question: I took a new clean install of OSX 10.9.3 and installed pip, and then did
pip install pandas
pip install numpy
Both installs seemed to be perfectly happy, and ran without any errors (though
there were a zillion warnings). When I tried to run a python script with
import pandas, I got the following error:
numpy.dtype has the wrong size, try recompiling Traceback (most recent call last):
File "./moen.py", line 7, in import pandas File "/Library/Python/2.7/site-packages/pandas/__init__.py", line 6, in from . import hashtable, tslib, lib
File "numpy.pxd", line 157, in init pandas.hashtable (pandas/hashtable.c:22331)
ValueError: numpy.dtype has the wrong size, try recompiling
How do I fix this error and get pandas to load properly?
Answer: You can install previous version of pandas.
pip uninstall numpy
pip uninstall pandas
pip install pandas==0.13.1
In my situation it solved problem...
|
how to merge file lines having the same first word in python?
Question: I have written a program to merge lines in a file containing the same first
word in python.However I am unable to get the desired output. Can anyone
please suggest me the mistake in my program?
**Note:- (line1,line 2)** and **(line4,line5,line6)** are merging since they
have the same first element
#input
"file.txt"
line1: a b c
line2: a b1 c1
line3: d e f
line4: i j k
line5: i s t
line6: i m n
#output
a b c a b1 c1
d e f
i j k i s t i m n
#my code
for i in range(0,len(a)):
j=i
try:
while True:
if a[j][0] == a[j+1][0]:
L.append(a[j])
L.append(a[j+1])
j=j+2
else:
print a[i]
print L
break
except:
pass`
Answer: Try this (give it the file as an argument).
Produces a dictionary with the lines you expect.
import sys
if "__main__" == __name__:
new_lines = dict()
# start reading file
with open(sys.argv[1]) as a:
# iterate file by lines - removing newlines
for a_line in a.read().splitlines():
# candidate is first word in every sentence
candidate = a_line.split()[0] # split on whitespace by default
# dictionary keys are previous candidates
if candidate in new_lines.keys():
# word already included
old_line = new_lines[candidate]
new_lines[candidate] = "%s %s" % (old_line, a_line)
else:
# word not included
new_lines[candidate] = a_line
# now we have our dictionary. print it (or do what you want with it)
for key in new_lines.keys():
print "%s -> %s" % (key, new_lines[key])
output:
a -> a b c a b1 c1
i -> i j k i s t i m n
d -> d e f
|
cx_Oracle - DLL load failed
Question: I have a problem importing cx_Oracle with Python. I know a lot of issues with
cx_Oracle have been discussed here, but it seems that I cannot find a solution
to my problem after reading all the related topics.
I have two machines, one is my computer and another one is a remote
workstation, which have similar configs (Windows 7, 64-bits). I need to
install cx_Oracle on the remote workstation but it does not work, whereas it
works fine on my computer (I can import the module successfully and connect to
my DB). On the remote workstation, I have the following error :
Traceback (most recent call last):
File "<pyshell#0>", line 1, in <module>
import cx_Oracle
ImportError: DLL load failed: The specified module could not be found.
I have double-checked my environment variables, and I re-installed cx_Oracle a
couple of times, but I cannot get it working... I did some research about this
problem and I am kind of stuck here, I do not understand why it is working
fine on my computer but not on this remote workstation (the only difference is
that this remote workstation is a VM).
Does anyone have an idea on what could be the issue?
Running Dependancy Walker on both cx_oracle.pyd (on my computer where it works
fine and on the remote workstation where cx_oracle does not work), the only
difference are the dll MSVCR100 amd MSVCR90 which are not found on my remote
workstation.
I have the following environment variables setup:
* `C:\Oracle as ORACLE_BASE`
* `C:\Oracle\instantclient_12_1` as ORACLE_HOME
* `C:\Oracle\instantclient_12_1` added to the "Path" variable
Both machines are 64-bit, Windows 7
I am running Python 2.7.5
I unzipped instantclient-basic-nt-12.1.0.1.0 in `C:\Oracle\instantclient_12_1`
I installed `cx_Oracle-5.1.2-11g.win32-py2.7s`
On the remote workstation, `sys.path` gives me :
> 'C:\Python27\Lib\idlelib', 'C:\Windows\system32\python27.zip',
> 'C:\Python27\DLLs', 'C:\Python27\lib', 'C:\Python27\lib\plat-win',
> 'C:\Python27\lib\lib-tk', 'C:\Python27', 'C:\Python27\lib\site-packages'
* * *
## EDIT 1
In the previous post, all files (Python 2.7, cx_Oracle package, Oracle Instant
client) were for 32 bit systems. I downloaded the same version of those files
for 64 bit systems and everything is working fine on my remote workstation
now.
## EDIT 2
Basically, the fix consisted for me in re-installing everything (Python,
Oracle Instant Client and cx_Oracle) for 64-bit systems instead of 32-bit
systems.
To summarize, this was my problem and how it got fixed: 1) I installed
Cx_Oracle (from 32-bit windows installation package) and Oracle Instant Client
(32-bit) and it was working perfectly on my 64-bit system running python 2.7.5
for 32-bit systems 2) I did the same thing exactly on a Virtual Machine
(running a 64-bit system as well) and it was not working 3) To get it working
on the VM, I re-installed everything for 64-bit systems (python, Instant
Client, Cx_Oracle) and it finally worked
<http://www.oracle.com/technetwork/database/features/instant-
client/index-097480.html> <http://sourceforge.net/projects/cx-
oracle/files/5.1.2/>
Also, Make sure to download the cx_Oracle and Instant client corresponding to
your DB version (11g in my case). Hope this helps.
Answer: I am running Oracle express on win 7 and python35(64 bit) .
This is how I managed to get my django-1.9 connect to oracle.
1. Installed cx_Oracle using pip (`pip3 install cx_Oracle`) instead of downloading the msi from pypi website.
2. Downloaded Oracle instant client 64 bit version from (<http://www.oracle.com/technetwork/topics/winx64soft-089540.html>) and extracted to c:\oraclexe (just to keep all oracle stuff at one place)
3. Created below environment variables:
`set ORACLE_BASE=C:\oraclexe set
ORACLE_HOME=C:\oraniclexe\app\oracle\product\11.2.0\server set
PATH=C:\oraclexe\instantclient_11_2;%PATH%`
4. Updated my django settings.py
`DATABASES = { 'default':{ 'ENGINE':'django.db.backends.oracle' 'NAME':'XE',
'USER':'hr', 'PASSWORD':'hr', 'HOST':'localhost', 'PORT':'1521', }, } ` That's
it. There after, my django migrations worked fine
|
Replace lowercase ASCII characters with X in Python
Question: What is the cleanest, most Pythonic code for replacing lowercase characters
with 'X' in a string? For example, `ABCDEFGhijklmnopQRSTUVwxyz` would become
`ABCDEFGXXXXXXXXXQRSTUVXXXX`.
Answer: I'd use
[`str.translate()`](https://docs.python.org/2/library/stdtypes.html#str.translate)
for that; easily the fastest method. A regular expression cannot touch this
for speed.
Python 2 version:
import string
map = string.maketrans(string.ascii_lowercase, 'X' * len(string.ascii_lowercase))
mapped = inputstring.translate(map)
Python 3 version:
import string
map = str.maketrans(dict.fromkeys(string.ascii_lowercase, 'X'))
mapped = inputstring.translate(map)
Demo (Python 2):
>>> import string
>>> inputstring = 'ABCDEFGhijklmnopQRSTUVwxyz'
>>> map = string.maketrans(string.ascii_lowercase, 'X' * len(string.ascii_lowercase))
>>> inputstring.translate(map)
'ABCDEFGXXXXXXXXXQRSTUVXXXX'
`str.translate()` is _orders of magniture_ faster here:
>>> import timeit
>>> import re
>>> def regex_replace(s, _sub=re.compile(r'[a-z]').sub):
... return _sub('X', s)
...
>>> regex_replace(inputstring)
'ABCDEFGXXXXXXXXXQRSTUVXXXX'
>>> timeit.timeit('f(s)', 'from __main__ import regex_replace as f, inputstring as s')
2.6076979637145996
>>> timeit.timeit('s.translate(m)', 'from __main__ import inputstring as s, map as m')
0.13378620147705078
The `str.translate()` version manages to do the task _20 times_ faster.
|
Using CouchDB Kit and Python; Trying to setup database without having to set DB inline
Question: I am using `couchdbkit` to build a small Flask app and I am trying to write
out some Python models so that interacting with the DB is easier (not inline).
Here is my code so far:
base.py
from couchdbkit import *
from api.config import settings
class WorkflowsCloudant(Server):
def __init__(self):
uri = "https://{public_key}:{private_key}@{db_uri}".format(
public_key=settings.COUCH_PUBLIC_KEY,
private_key=settings.COUCH_PRIVATE_KEY,
db_uri=settings.COUCH_DB_BASE_URL
)
super(self.__class__, self).__init__(uri)
class Base(Document):
def __init__(self):
server = WorkflowsCloudant.get_db(settings.COUCH_DB_NAME)
self.set_db(server)
super(self.__class__, self).__init__()
workflows.py
from couchdbkit import *
from api.models.base import Base
class Workflow(Base):
workflow = DictProperty()
account_id = IntegerProperty()
created_at = DateTimeProperty()
updated_at = DateTimeProperty()
deleted_at = DateTimeProperty()
status = StringProperty()
Controller **init**.py
from api.models import Workflow
blueprint = Blueprint('workflows', __name__, url_prefix='/<int:account_id>/workflows')
@blueprint.route('/<workflow_id>')
def get_single_workflow(account_id, workflow_id):
doc = Workflow.get(workflow_id)
if doc['account_id'] != account_id:
return error_helpers.forbidden('Invalid account')
return Response(json.dumps(doc), mimetype='application/json')
The error I keep getting is: `TypeError: doc database required to save
document`
I was trying to following the setup here
(<http://couchdbkit.org/docs/gettingstarted.html>) but extrapolating their
inline instructions to more of a dynamic context. Also, I am a Python newb, so
my apologies for my ignorance
Answer: This error happens if your model (Document) is not linked to the database
(correctly). This is done by with `set_db` method.
Also I think you should change your model:
from couchdbkit import Document
from couchdbkit import StringProperty, IntegerProperty
from couchdbkit import DateTimeProperty, DictProperty
class Workflow(Document):
workflow = DictProperty()
account_id = IntegerProperty()
created_at = DateTimeProperty()
updated_at = DateTimeProperty()
deleted_at = DateTimeProperty()
status = StringProperty()
I changed the Base inheritance to Document class. Also avoid using `from
some_module import *`!
When you have your model set like this then you can link your model and
couchdb like this:
Workflow.set_db(server)
NOTE: the code is not tested. I wrote it from my head so there could be some
mistakes.
|
How to access MySQL from python
Question: I've always used Xampp for db/ server purposes. I'm trying to use the same
with my Python project but cannot seem to get it to work.
Error from Python Shell
import MySQLdb
ImportError: No module named 'MySQLdb'
I've been all around but nothing seems to work. I'm on windows 7, Python 3.3.
Please someone advise. Links that would resolve this quick will be greatly
appreciated.
**Update:** Please note that it seems MySQL-python does not support python3
Answer: `pip install MySQL-python`
Run this in your Windows console or Linux terminal, and this problem should
disappear.
|
function names from config file in python
Question: I have a JSON config file which tells me what kind of distribution to sample
from. For example:
{ "parameter1" : { "distribution" : "exponential", "mean" = 5},
"parameter2" : { "distribution" : "poisson", "mean" = 3} }
The list above can be exhaustive. I need have a function which will read this
json file, and return the appropriate distribution to the calling code.
I tried using string concatenation and `eval()`, but that gives me the sample
values directly. I should be able to return the object/function to the calling
function.
Can some one help me do it?
My attempt:
import numpy.random as random
def getDistribution(distribution, params):
string= 'random.'+distribution
return eval(string)(params["mean"])
This returns a value to me. Is there a way to return a handle to the actual
distribution function like `random.exponential()` or `random.poisson()` which
I can use in the function calling `getDistribution()`?
Answer: You can use getattr to return the method (which is an attribute of `random`):
def get_method(name):
return getattr(random, name, None)
def get_distribution(method, params):
return method(params['mean'])
method_name = 'exponential'
method = get_method(method_name)
if method:
results = get_distribution(method, params)
else:
raise AttributeError('No such method in random: {}'.format(method_name))
`getattr` takes an optional third argument which is the value to return when
the attribute cannot be found. I am using this to explicitly return `None`.
You can change that to a default method that you want to use if the chosen
method name is not available.
|
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