Description

PEP 585 makes a lot of built-in types in the Python standard library generic as of Python 3.9. This deprecates a lot of imports from the typing module, since we don't need to import those types anymore to use generic types.

For example, this code was typed using the typing module:

from typing import List
def get_list() -> List[str]:
  return []

However, this is no longer necessary, since the built-in list type can be used as a generic type annotation now:

# look ma, no imports!
def get_list() -> list[str]:
  return []

Proposed solution

• Add import-linter back to the CI workflows. This was removed in a previous PR, but here's the original one that added it: https://github.com/jupyterlab/jupyter-ai/pull/546/files

• Add import-linter rules that forbid importing from the deprecated typing modules listed in PEP 585. Those are in the implementation section following the # symbols.

More details (click to expand)

For example, the tool should forbid imports like from typing import List and recommend that list just be used as a type directly.

Here's an image that refers to what I wrote above. Note how the recommended new type is shown first, and then the deprecated typing module follows the # symbol on each line.

• Run import-linter locally, fix all the imports, then open a PR for the main branch.

• Do the same for the 2.x branch. Normally the bot can be used to backport changes (@meeseeksdev please backport to 2.x), but there will likely be too many merge conflicts. I recommend just creating a separate branch and re-doing the steps here.

Context

From the PEP:

The deprecated functionality may eventually be removed from the typing module. Removal will occur no sooner than Python 3.9’s end of life, scheduled for October 2025.