python-dev summary, July 16-31

Andrew Kuchling
Tue, 07 Aug 2001 10:44:50 -0400

This is a summary of traffic on the python-dev mailing list between
July 16 and July 31 2001.  It is intended to inform the wider Python
community of ongoing developments.  To comment, just post to or comp.lang.python in the usual way. Give your
posting a meaningful subject line, and if it's about a PEP, include
the PEP number (e.g. Subject: PEP 201 - Lockstep iteration) All
python-dev members are interested in seeing ideas discussed by the
community, so don't hesitate to take a stance on a PEP if you have an
Summaries are archived at:

And following close behind the grossly delayed July 4-15 one,
here's the python-dev summary for July 16-31.

Two Python releases came out during this period.  As usually happens
in the interval surrounding a release, there were two kinds of
discussions on python-dev: a few lengthy ones thrashing around an
issue, and lots of little short ones to resolve a single bug or issue.


Python 2.1.1 released

Python 2.1.1, a bugfix release, was issued on July 20th as announced
by GvR.  Thomas Wouters was the release manager, and did a fine job of
backporting patches from the 2.2 CVS tree.

2.1.1 makes a slight modification to Python's license for the sake of
GPL compatibility, so there should no longer be any impediment (if
there ever was) to 2.1 finding its way into Linux distributions.
Roswell, the new Red Hat beta, already includes Python 2.1.1, and it
should also make its way into Debian testing before too long.

The first alpha release of Python 2.2 was also issued during this
period, on July 18.
2.2a1 includes new support for iterators and generators, plus the
usual pile of bugfixes, of course.  The source distribution for 2.2a1
was taken from 'descr-branch', the experimental branch in CVS
containing significant changes to the implementation of Python's
object model (PEP 252 and 253).  Guido is working on a tutorial for
these changes:

As usual I'm writing up an explanation of the changes in 2.2:

Neil Schemenauer posted some patches to make ExtensionClass compile
with 2.2a1, and ran the MEMS Exchange's basic unit tests successfully;
this amounts to 3569 test case over roughly 18,000 lines of code, so
this is a good sign.

No one else reported any problems with the descr-branch changes, so on
July 31 Tim Peters announced that the descr-branch would be merged
back into the trunk and the branch brought to a close.  That was done
a day or so later.


I came back from vacation to find comp.lang.python filled with an
endless and at times vitriolic flame war over PEP 238, "Non-integer
Division".  It seems to have been triggered to some degree by GvR
posting a proposed patch, which gave the impression that the issue was decided
and the solution set in stone:

The resulting firestorm didn't touch python-dev much, so I don't
need to summarize them.  They did lead to a revised version of PEP 238,
discussing many of the suggestions and ideas that were raised:


Another lengthy thread started when Eric S. Raymond reported on 
some discussions from the Open Source Conference:
	"The Perl people are receptive -- indeed, some of them are
	actively pushing -- the idea that their new bytecode should
	not be Perl-specific.  Dan Sugalski, the current lead for the
	bytecode interpreter project, has named it Parrot.  At the
	Perl 6 talk I attended, Chip Salzenberg speculated in public
	about possibly supporting a common runtime for Perl, Python,
	Ruby, and Intercal(!)."

Guido didn't immediately rule the idea out:
	"Obviously, just as the new design is aiming at Perl 6, it
        would be aiming at Python 3.  Nothing's impossible these days,
        so I am keeping an open mind.  I expect that in addition to
        the bytecode, the entire runtime architecture would have to be
        shared though for this to make sense, and I'm not sure how
        easy that would be, even if Perl is willing to be flexible.
        Most of Python's run-time semantics are very carefully defined
        and shouldn't be changed in order to fit in the common
The resulting discussions ranged over a number of topics: regex
implementations, Python's current virtual machine, the proposed Perl6
virtual machine, how to support both Python and Perl semantics at the
same time, and the mechanics of standards committees.  The only
concrete outcome of all this chatter was that Raymond will write an
architectural comparison of the existing Python and Perl bytecodes.

It's far too early to say if anything will come of this, so a common
VM should be viewed as an interesting, but not particularly likely,
possibility for now; when more details of the Parrot VM's design
become clear, the idea will no doubt resurface.

?!ng resurfaced after a lengthy absence, and proposed the cgitb module
for addition.  Demoed at IPC9, sets an exception-handling
hook using sys.excepthook that produces a nicely formatted traceback
instead of just letting the script cause an HTTP 500 'Internal Server
Error'.  For your debugging convenience, the traceback also includes
the local variables at each level of the stack.

The module itself isn't controversial, but ?!ng's suggestion of adding
an 'if' to to automatically enable it was.  Writing errors to
standard output instead of standard error, and in particular sending
them out to a potentially hostile Web user, made most people nervous.
The consensus was to add the module, but authors of CGI scripts would
have to choose to enable the formatted tracebacks, instead of having
them automatically enabled.

Frank Willison

On July 31st, we heard that Frank Willison, the editor-in-chief at
O'Reilly, had died suddenly the day before.  Paul Prescod posted the
news, adding an eloquent tribute:

Tim O'Reilly wrote a memorial on the O'Reilly Web site, and there's
also a page of comments from Willison's friends and acquaintances.

Random bits

Panu A Kalliokoski wrote 'Selecting', a module containing an
abstraction for writing asynchronous servers, much like asyncore but
claimed to be easier to use.

Paul Prescod reported on the existence of a Python port to the Sony
Playstation 2.  It exists, but unfortunately isn't publicly available.
Moshe Zadka asked if anyone has copies of old versions of Python
hanging around.  He's found 1.2, but would really like versions
preceding 1.0.

Discussion of the file encoding directive (covered in the previous
python-dev summary) continued, but there was no convergence toward a
solution.  It looks like this issue will be dropped for a while.

IPv6 support for the socket module was committed, and various minor
problems came up.  All were quickly fixed.

Unanswered questions

Some questions were posted that deserved answers, but didn't get any
(in public, at least).  I'll misuse my editorial power in an effort to
nudge someone into action.

Martin Sjögren wondered why the Py_BEGIN_ALLOW_THREADS and
Py_END_ALLOW_THREADS macros don't take an argument specifying a variable
to save the thread state to.  He said he needed this, but didn't explain why.

Andrew MacIntyre, who's working on an up-to-date OS/2 port of Python,
noticed that the parser doesn't use Python's memory allocation hooks
to allocate parser nodes.  When he tried modifying the parser code to
use the allocation hooks, the resulting interpreter worked but took a
massive performance hit.

Related Links
Python-dev archives:
Python project page on SourceForge:
Python Enhancement Proposals (PEPs):