How can I make language packs?

Question

I'm coding a Discord bot in Python using Discord.py Rewrite, and I would add language choice (English, French, etc...). But here's the problem.
If the user choice is one language on a server and another on another server, how can I tell the bot in Python "print that code in that language depending of the server"?

I also want the bot to detect (with text files) which languages are available, without having to restart the bot every time I add a new language.
Languages are sentences stocked in text files.

Even the code for this without Discord would be really great and helpful.

N.B. I know how to fetch specific data from servers (using json files), so that won't be a problem.

Answer 1

lang = "EN"
lang = "RU"
And others...?