app.py

#import definitions
import pandas as pd
import streamlit as st

df = pd.read_csv('Map-City-State-Zip-Lat-Long.txt', dtype=str, sep=';') 
st.title("Input a city or zip code and we will take you there!")

city_name = st.text_input("Please search for a city:")
lat = df[df["City"] == city_name][latitude].values[0]

st.write(lat)

#if city_name != "":
#    st.map({'cities' : city_name, 'lat' : lat, 'lon' : lon})
#    st.write(city_name, "is located at: ", lat "," lon)