Python: Calling function from another file gives a ModuleNotFoundError

Question

I'm trying to call a function from another file, but it keeps giving a ModuleNotFoundError. Does anyone know what I'm doing wrong?

File structure:

audio/
├─ tts.py
reddit/
├─ subreddit.py
config.json

tts.py:

from reddit.subreddit import *

print(reddit_thread())

Output:

from reddit.subreddit import *
ModuleNotFoundError: No module named 'reddit'