code: def is_default_port(self):
          
          if self.port is None:
              return False
          default = DEFAULT_PORTS.get(self.scheme)
          if default is None:
              return False
          return self.port == default
docs: A check for default port.
  
          Return True if port is default for specified scheme,
          e.g. 'http://python.org' or 'http://python.org:80', False
          otherwise.