[Python-Dev] breaking list.append()

[Paul Prescod]

Guido van Rossum wrote:
> 
> ..
> Multi-arg
> append probably won't be the only reason why e.g. Digital Creations
> may need to release an update to Zope for Python 1.6.  Zope comes with
> its own version of Python anyway, so they have control over when they
> make the switch.

My concernc is when I want to build an application with a module that
only works with Python 1.5.2 and another one that only works with Python
1.6. If we can avoid that situation by making 1.6 compatible with 1.5.2.
we should. By the time 1.7 comes around I will accept that everyone has
had enough time to update their modules. Remember that many module
authors are just part time volunteers. They may only use Python every
few months when they get a spare weekend!

I really hope that Andrew is wrong when he predicts that there may be
lots of different places where Python 1.6 breaks code! I'm in favor of
being a total jerk when it comes to Py3K but Python has been pretty
conservative thus far.

Could someone remind in one sentence what the downside is for treating
this as a warning condition as Java does with its deprecated features?
Then the CP4E people don't get into bad habits and those same CP4E
people trying to use older modules don't run into frustrating runtime
errors. Do it for the CP4E people! (how's that for rhetoric)
-- 
 Paul Prescod  - ISOGEN Consulting Engineer speaking for himself
"We still do not know why mathematics is true and whether it is
certain. But we know what we do not know in an immeasurably richer way
than we did. And learning this has been a remarkable achievement,
among the greatest and least known of the modern era." 
        - from "Advent of the Algorithm" David Berlinski
	http://www.opengroup.com/mabooks/015/0151003386.shtml