lemmy2opml: Export and import Lemmy community subscriptions

I wrote a Python script that takes your Lemmy credentials and outputs your subscribed communities to an OPML file. The script can also take an OPML file as input and subscribe a user to all of the communities listed in the file.

The motivation behind the script is to allow users to:

• easily follow their subscribed communities from an RSS feed reader;
• back up their subscribed communities in case their account is lost or they want to migrate to a different instance; and
• share their subscribed communities with each other, thus facilitating discoverability of communities.

Hopefully people find it helpful. More information in the README.