new_contents: #! /usr/bin/env python 
  
  
  #This script demonstrate recursion
  #check if a given string is a palindrome
  
  
  def is_palindrome(s):
      ''' (str) ----> bool
      Return Ture or False if a str is palindrome or not
      >>> is_palindrome("a")
      True
      >>> is_palindrome("ab")
      False
      >>> is_palindrome("abba")
      True
      '''
      if len(s) <= 1: 
          return True
      else:
          return s[0]==s[-1] and is_palindrome(s[1:-1])
  import doctest
  doctest.testmod()
  
  #Fibonacci numbers
  #0  1 1 2 3 5 8 13 21....
  
  def fib(x):
      '''Retrun fibonacci of x, where x is a non-negative int'''
      if x==0 or x==1:
          return 1
      else:
          return fib(x-1) + fib(x-2)
      
  # pythonic way 
  
  def is_palindromev2(s):
      return s==s[::-1]
  
subject: Create is_palimdrome.py