[Distutils] [Catalog-sig] pre-PEP : Synthesis of previous threads, and irc talks + proposals

[Tarek Ziadé]

On Tue, Oct 7, 2008 at 2:42 PM, Phillip J. Eby <pje at telecommunity.com> wrote:
> At 10:07 AM 10/7/2008 -0400, Tarek Ziadé wrote:
>>
>> The -m feature of setuptools is nice, but it activates one version at
>> a time, and
>> this is globlal to Python unless each application is handling the
>> version switch,
>> wich is pretty heavy.
>
> With or without the -m switch, scripts installed by setuptools will find the
> version they are specified to use, without the user needing to do anything.
>  So, you can have a default version of an egg (used by the interpreter and
> non-setuptools scripts), and then some non-default versions that are used by
> scripts.
>
> zc.buildout and virtualenv also have their own ways of accomplishing the
> same thing, e.g., by hardcoding paths in an installed script.

in a plain python setup,

If foo 1.2 is the default, and a package wants use foo 1.4,
it needs to specifically call pkg_resources.require() in the code, to
activate it in sys.path
before importing "foo" in the code.

Since each package can list with setuptools its dependencies with
versions in install_requires,
how hard  would it be to automatically call the right "require()"
calls when the package is used ?

Tarek
-- 
Tarek Ziadé | Association AfPy | www.afpy.org
Blog FR | http://programmation-python.org
Blog EN | http://tarekziade.wordpress.com/