Is it possible to obtain the number of followers generated by an account on a specific day?
with Twitter API v2 python

Yes but you will have to get the followers, cache the results, then the next day, get the followers again, and compare the results. There are no timestamps to work with to do this retrospectively. Any python library that calls GET /2/users/:id/followers | Docs | Twitter Developer Platform will work, but it’s up to you to make the comparisons and aggregate by day.

does this work with python?

I’m using the ‘tweepy’ library in python, could you give me a small example if it’s possible to do it?

Yes - see the “Get User’s Followers” example on Examples — tweepy 4.12.1 documentation

You’ll then have to save the result however you like, and then add the logic and schedule to repeat the same thing and compare results.

But can I select the day I want to know the number of followers I got on that day?

No, there is no way to do that in the API - you will have to gather the data over time yourself into a database and then you’ll be able to work that out.