PySDL2 FAQ

This is a list of Frequently Asked Questions about PySDL2. If you think, something is missing, please suggest it!

On importing…

… my script fails and complains that a SDL2 library could not be found!

Do you have the libraries properly installed? If on macOS or Windows, try running pip install pysdl2-dll and opening a fresh terminal to fix the problem. If on Linux or similar, did you follow the operating system’s way of installing or registering libraries? If you placed the libraries in some folder, make sure that the PYSDL2_DLL_PATH environment variable points to the correct location.

… my script fails complaining that the found SDL2 library can’t be used!

Do you use a 64-bit operating system? Please make sure, that the Python interpreter and that the SDL2 libraries are either 64-bit ones or 32-bit ones. A 32-bit Python interpreter can’t deal with a 64-bit library and vice versa.

Using…

… the sdl2 API is weird. Why do you use the SDL_ prefix all the time?

The low-level APIs for SDL2, SDL2_mixer, SDL2_ttf, … shall represent a clean wrapping around the original C API calls. Thus, if you have to search for documentation or want to make a Python to C conversion (or C to Python), most of the code cleanly maps to the original API naming and layout and you do not have to think about whether you had to use SDL_ or TTF_ or whatever as prefix or suffix.

… the sdl2 API is does not comply to PEP-8. Please make it PEP-8 compatible.

Most of the API is PEP-8 compatible. The low-level bindings to SDL2 and related libraries however use the exact naming (including capital letters) as the functions or structures, they map to. See the previous entry for the reason of that.

How do I…

… save my surfaces as image files?

You can use sdl2.SDL_SaveBMP() to save them as bitmap files. Other formats are currently unsupported, but might be added to the sdl2.ext package in the future.

Font handling…

… is too hard. Why can’t it work the same way as pygame does?

The sdl2.sdlttf API does not know about platform-specific font locations and is unable to resolve font paths based on e.g. the font name or typeface. It’s not its job and PySDL2 likewise does not provide such functionality. If you need improved font detection support, you might want to take a look at the sysfont module of the python-utils project, which can be found at https://bitbucket.org/marcusva/python-utils/. That said, it’s usually a bad idea for a projects to rely on system fonts that may not be available on every computer: finding a free-use font you like and bundling it with your code is much safer.