Checking for multiple exceptions.

repro.py

import praw

SUB_NAME = "###"
# ^ This name should be a subreddit that only allows link posts and not
# self posts. Preferably you should mod it (but not with the account
# that you run this script as), because it is going to get spammed.

reddit = praw.Reddit()  # fill in

subreddit = reddit.subreddit(SUB_NAME)
for x in range(50):
    try:
        subreddit.submit(str(x), url=f'https://duckduckgo.com/?q={x}')
    except praw.exceptions.APIException as e:
        assert e.error_type == 'RATELIMIT'
        print(f'Successfully post rate-limited in {SUB_NAME}')
        break
        
subreddit.submit('Hello World', selftext='')  # throws APIException