Ability to exclude certain dependencies altogether

[valentincalomme]

Issue Kind

Brand new capability

Description

In some of my projects, we decide to exclude the use of specific dependencies (i.e. pandas). Whilst it is easy to check during a code review if someone attempted to add it as a dependency by checking the pyproject.toml file, it isn't easy to know if pandas is a sub-dependency of another dependency.

I envision something like an exclude field in the poetry specification that would list packages, and if any of these show up as necessary dependencies, the install should fail.

Impact

This would require a new input type in the pyproject.toml file and additional checks when resolving dependencies.

Workarounds

Right now, I am using tricks using poetry show to list all dependencies and manually check these files, but I wish there were an automatic way to define this in the pyproject.toml file.

Obviously, there are ways to exclude certain versions of a package, but I'd like to exclude all versions of a package.

[github-actions[bot]]

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