[Distutils] Parsing setup()

[Rob]

Phillip J. Eby wrote:
> If you use "-e sometmpdir" as an option, you can have the .egg-info put
> in a temporary directory with a known location.  You need this because
> some package layouts don't have the .egg-info in the package root, so
> the rest of your stuff won't work.
>
> To be honest, though, I think you're going to way too much trouble
> here.  Just what exactly is the use case here?  Couldn't you just
> easy_install the package to a temporary directory with --no-deps?  Why
> do you think you need to inspect the setup.py in the first place?
>

Sorry, I should have explained what I was attempting.

The code is going to be used for g-pypi[1], a tool I wrote specifically for
creating ebuilds for Gentoo's portage package manager. It creates ebuilds
by using setuptools and querying The Cheese Shop.

We still use setuptools/distutils normally, I'm just grabbing the
dependency info
to help create the ebuilds which still have to have all the dependency info in
them (portage doesn't use easy_install).

> (You might also want to consider using the
> setuptools.sandbox.run_setup() function instead of os.system.)
>

That looks much better, I'll check that out.

> In general, I would suggest that trying to work your way around
> setuptools' APIs is a very bad idea.  More often than not, you will miss
> one of the nine jillion supported configurations and thus will end up
> with a tool that only works on your system...  *sometimes*.
>
> Case in point: your code above depends on the .egg-info being in the
> setup directory, which is often not the case.  Zope packages, for
> example, usually have a src/ or lib/ subdirectory that will be where the
> egg-info is.  Other packages may have it in other places, perhaps even
> more deeply nested.
>
> Pretty much *any* place where you are reading a file format directly or
> looking at directory contents yourself, you're probably breaking
> something that setuptools has encapsulated for a Very Good Reason.  When
> in doubt, ask.  :)
>

I'll keep all that in mind. I was thinking of making the code more general in
the future in case someone else wanted to use it for a different package
manager and needed to find out all the dependencies before creating
rpm's or debs etc.

So far it's working good - it's better than downloading, unpacking and
reading all the setup.py's by hand, which we'd been doing ;)


Thanks, Phillip!

[1] g-pypi:
http://tools.assembla.com/g-pypi