What hook language should I use for pre-commit hooks written in Python?

I’m working on a local pre-commit hook written in Python. At first, I saw this quote from the pre-commit documentation:

python

The hook repository must be installable via pip install . (usually by either setup.py or pyproject.toml).

I made the repo with the local hook installable using pip install ., but later found out that that isn’t supposed to work with local hooks.

More recently, I created a bare-bones .pre-commit-config.yaml that looks like this:

repos:
    -
        repo: local
        hooks:
            -
                id: &id1 test1
                name: *id1
                language: python
                entry: python -c "print('Hello, world!')"
                always_run: true
            -
                id: &id2 test2
                name: *id2
                language: system
                entry: python -c "print('Hello, world!')"
                always_run: true

Both seem to do the same thing.

Here’s my question: for local hooks, is there any difference between using the python language and the system language? Should I prefer one over the other when writing hooks in Python? I would think that system hooks would rely on the user’s PATH (and that python hooks might not), but the python command isn’t on my PATH normally, and the hook still works (I start a nix-shell when I want to run python).