> Funnily, GPT-4 seems like it generates pretty bad C code but pretty good Python code.

Back when OpenAI had code-specific models based on GPT-n they were generally specifically advertised as best at Python; I suspect their coding-related training data and human feedback on coding tasks all favors Python by a significant amount (and I supect that that actually gets reinforced by positive feedback, since this makes it most likely that they get used with Python over time, too.)