[Distutils] Low Level API for translating distutils/setuptools metatdata to Debian metadata

[Zooko Wilcox-O'Hearn]

>     * Provides a mapping between python project names and Debian
>       binary/source package names
>     * Converts setuptools versions to Debian versions while  
> maintaining
>       sort order
>     * Can introspect an .egg-info directory to figure out the Debian
>       dependencies for use in the debian/control file. It can also
>       handle/understand extras (I Hope!)

I looked briefly at this code, and it appears that it is doing purely  
syntactic mapping between Debian package names and Python  
distribution names, for example:

def py_to_bin(setuptools_project):
     """Convert a setuptools project name to a debian binary package  
name"""
     return _PY_TO_BIN.get(setuptools_project, 'python-%s' %  
setuptools_project.lower())

This works most of the time, but it isn't reliable.  For example, the  
module name is "OpenSSL", the distribution name is "pyOpenSSL", and  
the Debian package name is "python-openssl":

http://packages.debian.org/sid/amd64/python-openssl/filelist

That's why I contributed a patch to stdeb which uses the Debian  
database of which files are included in which packages (the same  
database that generates the web page linked above):

http://github.com/astraw/stdeb/blob/ 
647dd441a1712f8df37b5f7f5ba22ab6aeb2c3e7/stdeb/util.py#L135

The way stdeb does it looks in the database for files named  
"$DISTRIBUTION-$VERSION-py$PYTHONVERSION.egg-info".  The Debian  
package that includes such a file is the Debian package that you need  
to install in order to satisfy a dependency on $DISTRIBUTION,  
$VERSION.  This works regardless of whether the Python package is  
built with distutils or setuptools, and indeed it works for all  
packages that I know of.  (There is actually one exception: the  
Debian package for setuptools itself doesn't include a version number  
in its .egg-info filename:

http://packages.debian.org/sid/amd64/python-setuptools/filelist

It has a file named:

/usr/share/pyshared/setuptools.egg-info/

I guess we should add a fall-back-with-warning behavior to stdeb that  
if it can't find "$DISTRIBUTION-$VERSION.egg-info", but it can find  
"$DISTRIBUTION.egg-info", then it should (optionally) assume that the  
Debian package that has that file will satisfy the requirement,  
regardless of the version number in the requirement.   That, or  
someone should open a ticket asking Debian to add a version number to  
that filename.

The exact regexp is currently:

egginfore=("(/(%s)(?:-[^/]+)?(?:-py[0-9]\.[0-9.]+)?\.egg-info)"
                % '|'.join(req.project_name for req in requirements))

If you would be interested in including this mechanism to query the  
database in van.pydeb, I would be happy to advise you.

Regards,

Zooko