flair_updater.py

import os
from datetime import datetime
from praw import Reddit

reddit = Reddit(**{
    key: os.getenv(f"REDDIT_{key.upper()}")
    for key in (
        "client_id", "client_secret", "username", "password", "user_agent"
    )
})

with open("reference_url.txt") as f:
    reference_url = f.read()
reference_comment = reddit.comment(url=reference_url)

delta = datetime.utcnow() - datetime.fromtimestamp(reference_comment.created_utc)

with open("flair_tpl.txt") as f:
    flair_tpl = f.read()
flair = flair_tpl.format(delta.days)

subreddit = reddit.subreddit("Uruguay")
for template in subreddit.flair.templates:
    if template["text_editable"]:
        subreddit.flair.set("Samus_", flair, flair_template_id=template["id"])
        break

print(datetime.now().isoformat())
print(flair)