PEP 725: Specifying external dependencies in pyproject.toml

[pradyunsg (Pradyun Gedam)]

@kknechtel

Is it explicitly desired to keep “external” dependencies listed in separate places from pure-Python dependencies that are used in the same context?

Yes.

The tooling that handles this information does not need to understand Python requirement specifiers and, relatedly, these will have different behaviours and semantics than regular Python dependencies. Separating things that have different behaviours and semantics is intentional.

@kknechtel

The reason I ask is because I have an idea for using a table to describe a dependency that needs complex information (perhaps a package-specific index URI), or to reuse a complex specification (even just PEP 508 allows a fair bit) with a simple name that can be applied in multiple contexts; or just to write things out in a more explicit long form.

Please see PEP 633 – Dependency specification in pyproject.toml using an exploded TOML table | peps.python.org, which is a rejected PEP.