Hey @brainbudt,
I'd heavily suggest against adding Python to the container, as this is only built to host the code-server platform itself.
While I can't speak for Python, I've installed the PHP executable in my project space, and added it to my PATH, and it works pretty well.
The container does not seem to come with a package manager, as such, you'll either have to compile from source, or get the executables directly somehow, but what I'd suggest it setting up a shared environment with another container that has Python, as such, you'd simply SSH in from the commandline offered by VSCode's UI, and execute your code there.