The thread regarding 'how to do input in python' is great ..
Thanks for the contribution

This littel program allows you to find which key had been pressed using the Tkinter GUI.

# bind and show a key event with Tkinter 

from Tkinter import *

root = Tk()
prompt = '      Press any key      '
label1 = Label(root, text=prompt, width=len(prompt))
label1.pack()

def key(event):
    if event.char == event.keysym:
        msg = 'Normal Key %r' % event.char
    elif len(event.char) == 1:
        msg = 'Punctuation Key %r (%r)' % (event.keysym, event.char)
    else:
        msg = 'Special Key %r' % event.keysym
    label1.config(text=msg)

label1.bind_all('<Key>', key)

root.mainloop()

This code shows how to input a series of integers each separated by a space and then convert that input to a list of those integers:

# input a sequence of integer numbers separated by a space and convert to a list

def get_integer_list():
    while True:
        # get the sequence string and strip off any trailing space (easy mistake)
        str1 = raw_input("Enter a sequence of integers separated by a space: ").rstrip()
        try:
            # create a list of integers from the string using list comprehension
            return [int(num) for num in str1.split(" ")]
        except ValueError:
            print "Error: '%s' is not an integer! Try again." % num
            
print get_integer_list()

For example the input 1 2 3 4 5 turns into [1, 2, 3, 4, 5]

This small code allow you to list your computer's environment, things like processor, os, user and so on:

# list the environmental settings of your computer

import os

keys = os.environ.keys()
keys.sort()
for item in keys:
    print "%-22s : %s" % (item, os.environ[item])

As a bonus another small code to find the IP address of your computer:

# Get the IP address of the machine this program is running on
# or go to http://www.whatismyip.com/

import socket

print socket.gethostname()
print socket.getaddrinfo(socket.gethostname(), None)
# get just the IP address from the list's tuple
print socket.getaddrinfo(socket.gethostname(), None)[0][4][0]

Networks using the TCP/IP protocol route messages based on the IP address of the destination. An IP address is a 32-bit numeric address written as four numbers separated by periods.

This was part of a game, I modified slightly the code. The code checks that input is correct and within a supplied range.

def checkInput(type_string, present_value, low, high):
    '''uses a while loop, loops until an acceptible answer is given, then returns it'''
    prompt = "Present %s is %d, enter a new value (%d-%d): " % (type_string, present_value, low, high)
    while True: 
       try:
          a = int(raw_input(prompt))
          if low <= a <= high:
             return a
       except ValueError:
          print "Enter an integer number, please!"


# modify the present strength of 10 within the range (1-18)
modified_strength = checkInput("strength", 10, 1, 18)
print modified_strength

Code sample shows how to run a program and specified file(s) from commandline.

# using commandline to run a program and files

def process_datafile(filename):
    """load specified data file and process data"""
    # code to read file data
    # code to process data and show or return result
    print "Test only, file =", filename   # testing

if __name__ == '__main__':
    import sys

    # run the progam from the commandline and specify the data file(s) to be loaded
    # something like   myProgram data1.dat data2.dat
    if len(sys.argv) > 1:
        # sys.argv is a list eg. ['C:/Python24/Atest/myProgram.py', 'data1.dat', 'data2.dat']
        # sys.argv[0] is program filename, slice it off with sys.argv[1:]
        # using for loop, more than one datafile can be processed
        for filename in sys.argv[1:]:
            process_datafile(filename)
    else:
        print "usage myProgram datafile1 [datafile2 ...]"

You can use a global variable within a function by prefixing it with the word "global". Here is an example:

# keep track of how many times a function has been accessed
# using a global variable, somewhat frowned upon
def counter1():
    global count
    # your regular code here
    count += 1
    return count

# test it
count = 0         # a global variable
print counter1()  # 1
print counter1()  # 2
print count       # 2  variable count has changed
print

The trouble with a global variable is with using it somewhere else in a large program. Everytime you call this function its value will change and may lead to buggy code.

One solution is to use the namespace of the function, making the variable more unique. It gives you a hint where it is used, for example:

# avoid the global variable and use the function namespace
def counter2():
    # your regular code here
    counter2.count += 1
    return counter2.count    

# test it
counter2.count = 0  # now count has counter2 namespace, notice the period
print counter2()    # 1
print counter2()    # 2
print

Ever wrote a Python program and wanted to use passwords? What good is password, if the user can simply look at your code and see it?

The module md5 comes to the rescue! It converts the password string to string containing series of hexadecimal numbers. You do that in program1, then copy and paste this hex string into your program (program2).

Here is program1 (keep that to yourself in save place):

# program 1, code to generate a hashed password
# the result is a series of hexadecimal numbers
# it is saved to one text file, so you can
# copy and paste it to program2 from any editor

import md5

# pick a password you can remember
password = "gummy"
pw_hashed = md5.md5(password).hexdigest()
print pw_hashed  # just testing
fout = open("MyHashedPassword.txt", "w")
fout.write(pw_hashed)
fout.close()

This is program2, showing only hex string hashed password, but user has to enter password 'gummy' for md5 to match:

# program2, copy hashed password from program1 and assign
# it to MYPASSWORDHASH as string, this is all user would see,
# if looking at your code

import md5

MYPASSWORDHASH = "c1944508a0d871c55b501624c36e0f68"
def get_password():
    # give it three tries
    for i in range(3):
        password = md5.md5(raw_input("Enter your password: "))
        password = password.hexdigest()
        if password == MYPASSWORDHASH:
            return True
    return False

def main():
    if get_password():
        print "Success"
        # do something here with rest of the program code
    else:
        print "Failure"
        # do something else here

if __name__ == "__main__":
    main()

Python allows you to combine a number of statements into one-liner:

str1 = "we willing women want warm winter woollies"

list1 = str1.split()
print list1  # ['we', 'willing', 'women', 'want', 'warm', 'winter', 'woollies']

list2 = [frag[:2] for frag in list1]
print list2  # ['we', 'wi', 'wo', 'wa', 'wa', 'wi', 'wo']

str2 = "".join(list2)
print str2  # wewiwowawawiwo

# combine all three statements
print "".join([frag[:2] for frag in str1.split()])

Here you have it, but watch out it becomes hard to read and understand at times. Me thinks, me just invented a new word "wewiwowawawiwo". Has nifty ring to it!

You can use Python program to extract picture from web page and save it. I have tested this with Windows XP, might work with other OS:

# load given picture from web page and save it
# (you have to be on the internet to do this)

import urllib2
import webbrowser
import os

# find yourself a picture on a web page you like
# (right click on the picture, look under properties and copy the address)
picture_page = "http://www.google.com/intl/en/images/logo.gif"

#webbrowser.open(picture_page)  # test

# open the web page picture and read it into variable
opener1 = urllib2.build_opener()
page1 = opener1.open(picture_page)
my_picture = page1.read()

# open file for binary write and save picture
# picture_page[-4:] extracts extension eg. .gif
# (most image file extensions have three letters, otherwise modify)
filename = "my_image" + picture_page[-4:]
print filename  # test
fout = open(filename, "wb") 
fout.write(my_picture)
fout.close()

# was it saved correctly?
# test it out ...
webbrowser.open(filename)