differences between pip & uv for opencv

[nim65s]

Summary

Hi,

Installing opencv-python & opencv-contrib-python from uv, or from pip (through uv export > requirements.txt then pip install -r requirements.txt) has the strange difference that accessing cv2.ppf_match_3d_ICP fail in the first case but success in the second.

Here is an example: https://github.com/nim65s/cv2-uv/actions.

pip freeze / uv pip freeze outputs are the same, though.

Am I missing anything ?

Platform

ubuntu 24.04

Version

0.6.2

Python version

3.13

[konstin]

Thank for the clear reproducer!

Both opencv-python and opencv-contrib-python contain a cv2 module with a cv2/__init__.py, but the content is different. By installing both, it's up to change which package "wins" by being installed last and overwriting the other package. It seems that your use case is only working if opencv-contrib-python==4.11.0.86 is installed (or at least, installed last), while opencv-python==4.11.0.86 doesn't work. Can you try removing opencv-python==4.11.0.86 from your package?

[nim65s]

Oh, you are right, I should have read opencv wheel doc 😅

The test on the reproducer show this is fixed.

I wish we had a way to declare incompatibilities between packages (here, opencv-contrib-python include opencv-python, so the first should declare that it "provide" or "conflict" with the second…), but no: https://discuss.python.org/t/can-python-package-metadata-wheels-explicitly-conflict-or-replace-others/39966