palindrome.py

import re
# def is_palindrome(sentence):
#     '''uses iteration to strip non alphanum
#     also performs a simple test for palindromes'''
#     pal = []
#     for x in sentence:
#         if x.isalnum() == True:
#             pal.append(x.lower())
#         else:
#             pass
#     if pal[:] == pal[-1::-1]:
#         return True
#     else:
#         return False

def is_palindrome(sentence):
    ''' uses recursive methods to check for palindromes'''
    thing = re.sub(r'[^A-Za-z]',"",sentence).lower()
    if len(thing) <=1:
        return True
    else:
        if thing[0] == thing[-1]:
            return is_palindrome(thing[1:-1])
        else:
            return False

# def is_palindrome(sentence):
#     '''uses iterative methods to check for palindromes'''
#     thing = re.sub(r'[^A-Za-z]',"",sentence).lower()
#     count = 0 #count does double duty here
#     for x in thing:
#         if x == thing[-1-count]:
#             count += 1
#         else:
#             pass
#     if count == len(thing):
#         return True
#     else:
#         return False

def main():
    name = input("Please enter a word or sentence > ")
    print(is_palindrome(name))

if __name__ == '__main__':
    main()