[Python-Dev] Backwards Incompatibility
Jeremy Hylton
jeremy@alum.mit.edu
Wed, 21 Feb 2001 16:53:21 -0500 (EST)
>>>>> "PP" == Paul Prescod <paulp@ActiveState.com> writes:
PP> Jeremy Hylton wrote:
>>
>> I don't recall seeing any substanital discussion of this PEP on
>> python-dev or python-list, nor do I recall a BDFL decision on the
>> PEP. There has been lots of discussion about backwards
>> compatibility, but not much consensus.
PP> We can have the discussion now, then. In my opinion it is
PP> irresponsible to knowingly unleash backwards incompatibilities
PP> on the world with no warning. If people think Python is unstable
PP> it will negatively impact its growth much more than the delay of
PP> some esoteric features.
You have a colorful way of writing :-). When we unleashed Python
2.1a1, there was a fair amount of discussion about nested scopes on
python-dev and on python-list. The fact that code would break has
been documented in the PEP since December, before the BDFL pronounced
on it.
Why didn't you say it was irresponsible then? <0.5 wink> If you're
just repeating your earlier arguments, I apologize for the rhetoric
:-).
PP> Let me put the ball back in your court:
PP> Is the benefit provided by having nested scopes this year rather
PP> than next year worth the pain of howls of outrage in
PP> Python-land. If we give people a year to upgrade (with warning
PP> messages) they will (rightly) grumble but not scream.
I've heard plenty of hypothetical howls and one real one, from Mark.
The alpha testing hasn't resulted in a lot of other complaints. I
just asked on c.l.py for problem reports and /F followed up with a
script to help find problems. Let's see what the result is.
I ran Fredrik's script over 4700 source files on my machine and found
exactly four errors. Two were from old copies of the Python CVS tree;
they've been fixed in the current tree. One was from Zope and another
was an *old* jpython test case.
Jeremy