Source code for lec13_files_from_web

""" Illustrates the use of HTML files over the web in programs

    Files from the web are opened using the urllib library

    After this, the file is processed in the same way as a file 
    on your own hard disk.

    Note we are using different methods to read the files
    but they are all equivalent and are used to illustrate the
    different methods
"""

import urllib

def is_palindrome(word):
    """ Returns True if the word is a palindrome, the word is the 
        same when read forward and backwards. 
        It returns False otherwise.

    """

    word = word.strip()
    word = word.lower()
    for i in range( len(word)/2 ):
        if word[i] != word[-i-1]:
            return False  ## if a mismatch is found, return False
    return True  # if no mismatch is found, return True



###########

if __name__ == "__main__":
    word_url = 'http://thinkpython.com/code/words.txt'
    word_file = urllib.urlopen(word_url)
    
    i = 0
    while True:
        i += 1
        word = word_file.readline()
        if word == '':  ## this is true when the end of file is reached
            break 
        if is_palindrome(word):
            print word.strip()