Backwards Compatibility of Python versions

[Jonathan Hogg]

On 3/2/2002 6:32, in article 7xbsf7dqj9.fsf at ruckus.brouhaha.com, "Paul
Rubin" <phr-n2002a at nightsong.com> wrote:

> So much for compatibility then.

I think I missed the beginning of this thread so I'm confused. Exactly which
new backwards incompatible feature of the recent Python versions is it that
is breaking people's old scripts?

So far I've seen complaints of 'x in somedict' which only affects writing
new code for the new Python interpreter, future division which is not
enabled yet by default, and the import __future__ mechanism, which again is
only meant to be called by new code on the new interpreter.

If you need to run code on 1.5.2 then don't use any of the new features;
this is a given. This goes just as much for library evolution as core
language changes.

Which *old* code of someone's has actually been broken so that it will not
run correctly on the newer interpreters?

Jonathan