code: def _is_url(url):
      
      regex = re.compile(
          r'^(?:http|ftp)s?://'  # http:// or https://
          r'(?:(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+(?:[A-Z]{2,6}\.?|[A-Z0-9-]{2,}\.?)|'  # domain...
          r'localhost|'  # localhost...
          r'\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})'  # ...or ip
          r'(?::\d+)?'  # optional port
          r'(?:/?|[/?]\S+)$', re.IGNORECASE)
      if regex.match(url) is not None:
          return True
      else:
          return False
docs: Used to determine if a given string represents a URL