Two conflicting implementations of python-magic (was API changes...)

[Rodrigo Bistolfi]

The python-magic API has changed in their 0.1 release, should we reflect this changes in Lalita (python-magic is a dependency for the url plugin.)
I attach a trivial patch just in case.

[Facundo Batista (facundo)]

I have a fully updated Karmic, and the python-magic version is like a bigger number: 5.03-1ubuntu1

We should support previous and newer versions. The problem is that the API seems to be the older one, and after an "import magic", you don't have a version attribute or anything.

In which system you have a newer version? What do you think about supporting two versions?

[Rodrigo Bistolfi (rodrigobistolfi)]

I installed python-magic from pypi in my Vector Linux and Slackware systems (12.1)
http://pypi.python.org/pypi/python-magic/0.1

Ubuntu is using a package from another source: http://packages.ubuntu.com/karmic/python-magic
They are splitting python-magic from the file package (source in http://www.darwinsys.com/file/)
We could pick one or make an adapter for supporting both. The pypi package is outdated, but how this dependency will be handled by lalita if installed through pipy?

[Facundo Batista (facundo)]

Rodrigo: I think we should support both versions.

Not a very big adapter, just the minimum needed for this to work.

What do you think?

[Rodrigo Bistolfi (rodrigobistolfi)]

I agree, I will get both sources and take a look.

[Facundo Batista (facundo)]

Hi Rodrigo, do you have any news about this?

Thanks!

[Rodrigo Bistolfi (rodrigobistolfi)]

Hi Facundo, sorry about the delay, I have been busy at work.
How do you think we should implement this? I have a few questions:

1) Should the fix be part of the url.py module, or should it be available for other plug-ins, maybe through a separated utils.py module or similar? I think it should go in url.py and others can pick it up from there if needed. The plug-ins folder needs a clean up already.

2) Do we need a simple adapter, providing an unified interface for both implementations or do we need something fancier, maybe using zope.interface ?

[Facundo Batista (facundo)]

Hola Rodrigo! After we discussed this on IRC and you did some mockups... did you make a decision about how to proceed?

[Rodrigo Bistolfi (rodrigobistolfi)]

Hi Facundo! Given that we concluded that the metaclass approach was the more elegant, I think we should take that approach. If we find maintenance related problems, I can switch to one of the other proposed implementations. I am cleaning up and I will branch it for reviewing. If you agree, we can evaluate the solution until lalita becomes Beta.