[Python-Dev] Re: Stability and change

Guido van Rossum guido@python.org
Mon, 08 Apr 2002 13:34:58 -0400

> >I wonder if decoupling more of the standard library isn't a good idea,
> >although it flies in the face of "batteries included".  One thing I

> I'd like this approach, though perhaps the "Batteries Included"
> distribution rather than the standard library should be handled like
> this.

For a batteries included release, this would be great.

> It would also require finalizing a catalog implementation (at
> last!)

I believe Kapil is working on it; he's presenting a paper at OSCON2002.

> An open question is how to avoid the CPAN trap of having your modules
> require you to upgrade your Python installation.  Perhaps each module
> version would specify the Python version it's compatible with.
>    Module version         compat. with
>      0.0.1                  Py2.1
>      0.0.2                  Py2.1
>      0.0.5                  Py2.2

Ideally it should list a range of versions (or a set?).  Of course, the
upper end of the range may need to be adjusted when new releases come
out -- nobody knows whether Module 0.0.5 will be compatible with Py2.3
until the latter is released.

> So when you're on Python 2.1, you can only get upgraded to 0.0.2.  The
> problem is, if the developer of version 0.0.5 didn't realize that it
> was incompatible with 2.1, you'll get upgraded to it and your system
> will be broken.  
> (Take package management far enough and you begin to reinvent Debian's
> APT.  I wonder if we could write a dpkg-like tool in Python and then
> just use APT on top of that?)

I think version dependency management is subject to the Logajan
paradox. :-(

--Guido van Rossum (home page: http://www.python.org/~guido/)