How can I add implicit dependencies to a dependency in Python Poetry?

My project depends on a package that I do not maintain: PackageA. PackageA depends on PackageB but does not explicitly specify PackageB as a dependency in its setup.py file.

Ideally, the PackageA maintainer would explicitly add PackageB as a dependency, but I can't control that.

I could simply poetry add PackageB to my project but then I would be taking a dependency on PackageB, when really I only want to depend on PackageA.

I attempted to manually modify the [package.dependencies] for PackageA in the poetry.lock file to add PackageB = * but Poetry began complaining. That also seems like a bit of a hack as the dependency relationship is still not modelled anywhere in the pyproject file.

Is there a way that I can tell Poetry that I want to take a dependency on PackageA but that PackageA also has a dependency on PackageB?

Solution

it seems like some extra work to me but i guess you could do

[tool.poetry.group.packageA]
optional = true

[tool.poetry.group.packageA.dependencies]
packageA = "^1.3.4"
packageB = "^1.2.3"

then install with poetry install --with packageA

or remove the optional=true flag that i left in like a dummy and it will work just as you expect :P I think (thanks @Nathan)

or you could add it to the extras section

[tool.poetry.extras]
packageA = ["packageA","packageB"]

and install with poetry install -E packageA

but if it was me i would just add it to my main dependencies