code: def diff(a, b):
      
      return ''.join(
          Differ().compare(
              a.splitlines(keepends=True),
              b.splitlines(keepends=True)
          )
      )
docs: Return the difference between two strings
  
      Will return a human-readable difference between two strings. See
      https://docs.python.org/3/library/difflib.html#difflib.Differ for more information about the output format
  
      Args:
          a (str): Original string
          b (str): New string
  
      Returns:
          `str`