PRAW Why does this recursive function to check if a url is an image return none?

Question

I wrote a recursive function to detect whether or not the url of any given post contained " .jpg " or " .png ". But if it doesn't find an image on it's first try, it returns " None ". If I put a print statement in the function right below the "submission =" it does print out, but the string doesn't seem to exist when I try to return that value. My goal is to write a function that will always return an image url. Also I am writing this for a discord bot, so if I should be using async praw let me know.

Thanks.

import praw
import random
reddit = praw.Reddit(client_id = "CLIENT_ID", client_secret = "CLIENT_SECRET", user_agent= "USER_AGENT")


def is_image():
    submission = random.choice([i for i in reddit.subreddit("RANDOM REDDIT").top("all", limit=100)])
    if ".jpg" in submission.url or ".png" in submission.url:
        return submission.url
    is_image()
    return 
print(is_image())

Answer 1

Instead of pointlessly calling is_image() after the if-statement, you should return it.

def is_image():
    submission = random.choice([i for i in reddit.subreddit("RANDOM REDDIT").top("all", limit=100)])
    if ".jpg" in submission.url or ".png" in submission.url:
        return submission.url
    return is_image()

print(is_image())