Pygame

Pete Shinners started Pygame in 2000 after the PySDL project had gone quiet. It wraps SDL in a Pythonic API: surfaces to draw on, Rect for basic collisions, sprite groups, sound and an event queue. The game loop you write yourself, which is rather the educational point.

It has never been fast — Python plus software rendering sets the ceiling — but it has been forgiving, and the PyWeek game jam has been built around it since 2005. In 2023 several of the active maintainers left to continue as the community fork pygame-ce, a fate most long-lived hobby projects meet eventually. People who want a real engine with Python-flavoured syntax tend to end up in GDScript instead.