Git pre-commit hooks only for a specific subfolder?

Question

If you use pre-commit, specify files to include (or exclude to exclude) specific directories, e.g. run hooks only in my_dir:

files: ^my_dir/
repos:
-   repo: https://github.com/pre-commit/pre-commit-hooks
    hooks:
        ...

or run everywhere but inside my_dir:

exclude: ^my_dir/
repos:
-   repo: https://github.com/pre-commit/pre-commit-hooks
    hooks:
        ...

If you have a long list of exclusions, use verbose regex:

exclude: >
  (?x)^(
      path/to/file1.py|
      path/to/file2.py|
      path/to/file3.py
  )$

you can also apply these to specific hooks only, just do:

-   id: my-hook
    exclude: ^my_dir/