> What I'm dismissing is that "pip install some-package" can define a global startup task for your interpreter. I shouldn't get debugging or code coverage enabled every time I run "python" just because I installed some package

At least for the coverage tools they all play nice and require an environment variable to be set for them to take.  For example, `coverage-enable-subprocess` requires `COVERAGE_PROCESS_START=...` in order to start: https://github.com/bukzor/coverage_enable_subprocess/blob/9a0f4df99f0d008eba305c673dfae4269c6c5642/setup.py#L14

> I should have to start that package somehow.

`pip install` is a pretty good opt-in already imo

> Instead of just shipping "my_module.foo", you ship "my_module.py" and "_my_module.foo", where "my_module.py" looks like:

but that's exactly my point, now you have to ship extra junk python files when it's a way better experience to have the hooks _just work_