flair-count.py

import praw
from collections import Counter
from pprint import pprint

reddit = praw.Reddit(username="", password="", client_id="", client_secret="", user_agent="")

flairs = list(reddit.subreddit("teenagers").flair(limit=None))

print("Total flaired users:", len(flairs))

pprint(Counter([_["flair_text"] for _ in flairs]))

# pprint(Counter([_["flair_css_class"] for _ in flairs])) # If you want to list by CSS class instead