[Python-Dev] Proto-PEP for maintaining backward compatibility

[Thomas Heller]

> > > You seem to be using it beyond its intended use.
> 
> > You mean the cross-version use? As I said, it works nice.
> 
> No, I meant that this module is part of the freeze tool.  That has no
> requirement to be backwards compatible, since each Python version
> comes with its own version of freeze.  Suppose that the .pyc file
> format changes in a backwards incompatible way (we're considering this
> too) and suppose modulefinder has to be changed.  I think it should be
> possible to do that without consideration for older Python versions.

In this case I propose to add it to the standard library
(or maybe Gordon's mf replacement, together with iu, his imputil
replacement ?).

> 
> > Anyway, if there is a strong reason to do so, it can be
> > removed from PEP 291 - but string methods and booleans
> > aren't such a reason (IMO).
> 
> I think it should be removed.  I want to avoid having random claims
> for backwards compatibility of arbitrary parts of the Python
> distribution, because the more of these we have, the more constrained
> we are as maintainers.
> 
Ok.

> The other cases are all packages that are being distributed separately
> by their maintainers for use with older Python versions.  I think your
> use case is considerably different -- you are simply borrowing a
> module.
> 

Thomas