code: def comment_stream(reddit_session, subreddit, limit=None, verbosity=1):
      
      get_function = partial(reddit_session.get_comments,
                             six.text_type(subreddit))
      return _stream_generator(get_function, limit, verbosity)
docs: Indefinitely yield new comments from the provided subreddit.
  
      Comments are yielded from oldest to newest.
  
      :param reddit_session: The reddit_session to make requests from. In all the
          examples this is assigned to the variable ``r``.
      :param subreddit: Either a subreddit object, or the name of a
          subreddit. Use `all` to get the comment stream for all comments made to
          reddit.
      :param limit: The maximum number of comments to fetch in a single
          iteration. When None, fetch all available comments (reddit limits this
          to 1000 (or multiple of 1000 for multi-subreddits). If this number is
          too small, comments may be missed.
      :param verbosity: A number that controls the amount of output produced to
          stderr. <= 0: no output; >= 1: output the total number of comments
          processed and provide the short-term number of comments processed per
          second; >= 2: output when additional delays are added in order to avoid
          subsequent unexpected http errors. >= 3: output debugging information
          regarding the comment stream. (Default: 1)