code: def is_int(string):
      
      try:
          a = float(string)
          b = int(a)
      except ValueError:
          return False
      else:
          return a == b
docs: Checks if a string is an integer. If the string value is an integer
      return True, otherwise return False. 
      
      Args:
          string: a string to test.
  
      Returns: 
          boolean