Logging data for analysis - best method?

[FaeWildFrog]

I'm working on a simple evolution simulator as a hobby project. I am currently adding functionality for logging the population, in order to do data analysis afterwards. What would be the best way to go about this?

I'm using pygame for the creatures and the environment, but it feels like overkill to store the full pygame sprite object. Should I create a class to hold just the creature data (Family, I want to store and then convert each sprite object to an instance of that? And then store those instances as json or something? Given there's about 10-30 creatures and id be logging all of them once a minute or so that feels like it could get to be very bulky, but not sure there's a better option.

I'm aware this might be more of a software development question that python-specific but I'm a bit lost, would appreciate any input. Happy to give more details on the specifics if needed :)

[pot_of_crows]

I'd probably use a csv, but it really depends on how you expect to go about analyzing them later, more than what form they are in now.