[Python-Dev] Re: Stability and change

Guido van Rossum guido@python.org
Wed, 29 May 2002 15:52:02 -0400

> Given all the recent flamage over this issue, probably I should have
> a separate "Porting to 2.3" section that summarizes everything to
> watch out for.

That section might start by noting that anything that prints Boolean
results (e.g. ``print a==b'') or converts them to strings might be
affected by the new bool values that are now often returned as Boolean

Skimming Misc/NEWS might be the most efficient way to find out other
things that could affect old code; e.g. I read that xrange's
deprecated features are now removed, assert no longer tests for
__debug__, an obscure change to __new__ and __init__, a change to
pickling objects with __slots__, and a restriction of sys.exit() to a
single argument (sure to bite someone).  Library: pwd, grp and
resource return enhanced tuples; a change in ftplib.retrlines.  At the
C API level (do you cover that?) the pymalloc changes probably warrant

And more, probably.

One question is how spin this.  Listing a long series of
incompatibilities presents the image of a language that has many
gratuitous incompatible changes -- which is not true and the opposite
of the message we want to convey.

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