code: def friendships_create(self, user_id=None, screen_name=None,
                             follow=None):
          
          params = {}
          set_str_param(params, 'user_id', user_id)
          set_str_param(params, 'screen_name', screen_name)
          set_bool_param(params, 'follow', follow)
          return self._post_api('friendships/create.json', params)
docs: Allows the authenticating users to follow the specified user.
  
          https://dev.twitter.com/docs/api/1.1/post/friendships/create
  
          :param str user_id:
              The screen name of the user for whom to befriend. Required if
              ``screen_name`` isn't given.
          :param str screen_name:
              The ID of the user for whom to befriend. Required if ``user_id``
              isn't given.
          :param bool follow:
              Enable notifications for the target user.
  
          :returns:
              A dict containing the newly followed user.