[packagekit] What-Provides for Python modules?

[Matthias Klumpp]

Hi!
I develop a cross-distro software installer based on PackageKit. In order
to support installation of Python software, it would be important for me to
be able to ask PackageKit which package provides which Python module.
This might not only be useful for me, as Python-developers can check if
all dependencies their script has are present and - if not - use PackageKit
to search for them and install them. This would be useful for users, as an
application could display a message like "Install package X to use this
script".
To make PackageKit support this, I would add a new enum
"PK_PROVIDES_PYTHON". Python tools which do e.g. "import xapian" can then
search for a package providing Xapian using the search-string "xapian". To
specify the Python version, the search would have to be "python3(xapian)".

To be useful, backends need to implement this feature, so: Which backend
does and which does not support searching for Python dependencies? Backends
need to store metadata about Python modules somewhere... (In APT, Python
modules can be searched via the package-name itself)

And one question in general: Do you think it makes sense to extend the
what-provides search to GIR data and other stuff which is primarily useful
for developers too? (Of course, users will benefit from it indirectly too)
We can already search for fonts, firmware/hardware-driver, modaliases,
codecs, mimetypes, postscript-drivers, plasma-services and libraries in
general.
Cheers,
   Matthias