How can I use auto-generated Python modules with editable builds

[voidtrance]

Is it possible to use auto-generated Python modules in editable builds?

I am generating a Python module with a bunch of ctypes.Structure structures from C code. This Python module is generated as part of a custom_target() and is being placed in the build artifacts directory ./build/cp314. However, when I try to load it, it attempts to load from the actual source directory.

[rgommers]

Yes it is possible, we do this in numpy and scipy for example. Python import statements in editable installs are resolved via importlib hooks, so what you want to avoid is assuming paths with __file__; if you need to access say a C file, locate it via https://mesonbuild.com/meson-python/how-to-guides/editable-installs.html#data-files

Your question is too brief to know exactly what the problem is - you may be talking about callbacks from C to Python or some such thing? If you provide a standalone reproducer of the problem you're seeing or share your actual project, we can say more.

[voidtrance]

Providing a standalone reproduces would be a non-trivial task. However, here is a more detailed explanation:

A custom_target generates a Python file like this example:

<path>/module.py

import ctypes

class A(ctypes.Structure):
    _fields_ =("var", ctypes.c_int)]

Because it is generated as part of a custom_target, the file is placed in <project dir>/build/cp314/<path>.

Now, in my Python application, I want to do import <path>.<module>. What I was seeing is that it would attempt to load it from <project dir>/<path> rather then <project dir>/build/cp314/<path>/module.py.

However, I don't know what I did but it is working properly now. We can close this discussion.

[rgommers]

However, I don't know what I did but it is working properly now.

Thanks, that's what I would expect indeed - it's a regular import statement, which should work. Marking as resolved.