gistfile1.txt

# Define a procedure is_palindrome, that takes as input a string, and returns a
# Boolean indicating if the input string is a palindrome. A palindrome is a string that is the same backwards and forwards. For example, “dad”, “malayalam”, and “wow” are examples of palindromes. 

def is_palindrome(s):
    s_length = len(s)
    pos = 0
    while pos <= len(s)/2:
        if s[pos] = s[s_length-pos]: 
            pos + 1
        else:
            return False



print is_palindrome('abab')
#>>> False
print is_palindrome('abba')
#>>> True
print is_palindrome('')
#>>> True
print is_palindrome('abcba')
#>>> True
print is_palindrome('abca')
#>>> False