Panu Matilainen wrote:
On Wed, 12 Sep 2007, Toshio Kuratomi wrote:
> Panu Matilainen wrote:
>>
>> Separating the namespaces is a fundamental problem for the dependency
>> extractor. For provides this is obviously not an issue, but requires
>> need to be generated without being able to actually locate (and possibly
>> import) the actual module. Python syntax for importing egg- and regular
>> modules is the same, so they need to live in the same namespace,
>> otherwise the manual Requires just turn into manual BuildRequires and
>> the depency extractor will be just adding syntactic sugar for nothing :)
>>
> I think I've figured out a way to make this almost work::
> import sqlalchemy
>
> is equal to Requires python(sqlalchemy)
>
> Any of these::
> __requires__='SQLAlchemy'
> pkg_resources.require('SQLAlchemy')
> requires.txt:
> install_requires = [ 'SQLAlchemy' ]
>
> are equal to python-egg(sqlalchemy)
>
> This breaks down when thinking about what happens in this case::
> __requires__='TurboGears'
> import pkg_requires
> import sqlachemy
>
> At this point you have to know whether TurboGears or anything that it
> requires has a requires.txt which includes ['SQLAlchemy']. If it does
> we are using the egg interface to sqlalchemy. If it doesn't we are
> using the normal interface.
>
> So, assuming we remove our patch that stops generation of egg-info files
> for distutils generated modules for F9, I agree that there isn't very
> much value for quite a bit of work.
Let me put it this way: why exactly do you want the eggs in a separate
namespace? If using modules from them *required* using new interfaces
it'd be a different story, but since they can be imported just like any
regular module they should be in the same namespace. (or am I missing
something here - I'm certainly not very familiar with the egg stuff?)
Well, the way I'm proposing in the egg draft we will have
compat-packages that are only importable via an egg interface. For
instance python-sqlalchemy0.3 has these directories::
%{python_sitelib}/SQLAlchemy-0.3.10-py2.5.egg/
%{python_sitelib}/SQLAlchemy-0.3.10-py2.5.egg/sqlalchemy
To be able to import it you need to do something like this:
__requires__='SQLAlchemy >= 0.3, < 0.4alpha'
import pkg_resources
import sqlalchemy
Or manually add %{python_sitelib}/SQLAlchemy-0.3.10-py2.5.egg/sqlalchemy
to sys.path.
The main python-sqlalchemy module would be directly importable or you
could select it specifically using something like
__requires__='SQLAlchemy >= 0.4, < 0.5'.
One possibility would be to *only* extract python module
dependencies
from egg modules and software using the new requires interfaces and
simply forget about the old-style modules.
I'd rather we extract old-style modules and forget about eggs as the
eggs don't come into play as often for us.
-Toshio