code: def user_getfield(self, field, access_token=None):
          
          info = self.user_getinfo([field], access_token)
          return info.get(field)
docs: Request a single field of information about the user.
  
          :param field: The name of the field requested.
          :type field: str
          :returns: The value of the field. Depending on the type, this may be
              a string, list, dict, or something else.
          :rtype: object
  
          .. versionadded:: 1.0