def is_banned(subreddit, user):
    """
    Lookup whether Reddit user is banned from subreddit

    :param subreddit: praw.Subreddit instance
    :param user: praw.Redditor instance
    :return: True if banned, False if not banned
    """
    url = 'r/{}/about/banned/'.format(subreddit.display_name)
    params = {'unique': subreddit._reddit._next_unique, 'user': user}
    if len(list(subreddit._reddit.get(url, params=params))) == 1:
        return True
    else:
        return False