feat: ability to override versions in constraints file

[aryarm]

Use-case

I am trying to test my project against different versions of python. Unfortunately, one of the dependencies in my lock file only supports a subset of the python versions that I'd like to test.

For example, in my particular situation, I'd like to test my project against python 3.7 and 3.11. numpy is a dependency of my project.
My lock file contains numpy v1.21.1, which is compatible with python 3.7 but not 3.11. I could upgrade my lock file to a version compatible with 3.11 (like numpy v1.23.2), but unfortunately, those versions are no longer compatible with 3.7

Feature request

I would like to be able to do something like this:

if python_version == '3.11':
    session.install(".", f"numpy==1.23.2")
else:
    session.install(".")

But I think this will fail because pip does not allow for overriding constraints files like this.
Is there anything that I can do in this situation? Is there a way for me to override constraints from my lock file in nox-poetry?

Related to

• matrix testing #289 (comment)

[patrick91]

@aryarm as a work around I did this:

session._session.install(f"django=={django}")

[aryarm]

@patrick91, great thanks! I'll try it out

can you say a bit more about why this works?

[patrick91]

@aryarm session._session.install(f"django=={django}") uses nox install command (which is just pip install ...) while session.install from nox-poetry uses pip --constraints ... install ... which will use the lock file (if I understood correctly) so it forces you to use specific versions, which is not what I/we want in this case 😊

[aryarm]

ah, I see! thanks

but I suppose the downside of this would be that none of the other dependencies would be locked, right?

[aryarm]

ok, I think I found a better approach to the problem using Nox's parametrization of python. Will this also work with nox-poetry, though? I want all except the parametrized versions to be locked.