[Distutils] PEP 376, Uninstallation and interoperability

[Vinay Sajip]

Eric V. Smith <eric <at> trueblade.com> writes:

> Speaking of namespace packages, 2 points:
> 
> 1. When deleting, you must either be aware of namespace packages and/or
> make sure to not delete source or .py[co] files that you did not
> install. One distribution could install foo.bar, and another then
> install foo.baz. If you install the first one, you cannot just remove
> foo. I hope this is obvious, but I'll say it here because it's a
> behavior unique to namespace packages, when it comes to python files (as
> opposed to bin, etc. directories).

That's clear enough. The worry is not so much about deleting files you didn't
install (any decent tool wouldn't do that - at least, not without warning the
user and asking for confirmation). My concern is more about not warning the
user when it makes sense not to.

I just haven't got around to adding namespace packages to the shared location
stuff in distlib, but it'll be there soon.

> 2. Does the metadata need to contain information about namespace
> packages? It's settable in distribute/setuptools' setup.py. I'm not sure
> if the need for it has been obviated by PEP 420 or not. And I'm also not
> sure if metadata is needed for pre-PEP 420 namespace packages, and if
> so, if we want to support them.

We probably do want to support them - at least, distlib is aiming to remain
2.x/3.x compatible and to ease migration from 2.x, so you need to consider
pre-PEP 420 namespace packages too. Easing migration means that we shouldn't
lose any metadata which setuptools provides (such as namespace package
declaration in metadata).

Regards,

Vinay Sajip