Doing a Python development environment inside of Docker can get particularly obnoxious in the long run because there are approximately a zillion ways that a base image upgrade can break things by changing something about the system Python packages.

(And by the time it happens you might have a real mess on your hands because by that point the dev container's dockerfile has quite possibly grown into an undocumented spaghetti tangle of band-aids as a result of every dev on the team tweaking things in whatever way seemed to make the most sense at the time without a whole lot of regard for the end-to-end cohesiveness of the situation.)

The standard advice in the Python community is "never trust the system Python", but tools like pyenv that we have for protecting ourselves from the operating system aren't always straightforward to get working sensibly inside of a container. It seems like it should be easy, but I've seen people get it wrong far more often than I've seen them get it right.

A big part of the problem is that the Python community has developed an extremely severe case of TMTOWTDI when it comes to dependency management, packaging and deployment. It's led to a situation where, if you're just googling around for problem solutions in an ad-hoc manner, you're likely to end up with a horrible chimera of different philosophies of how to do Python devops, and they won't necessarily mesh well together.