python-dev Summary for 2003-01-16 through 2003-01-31
3 Feb 2003 18:43:51 -0800
python-dev Summary for 2003-01-16 through 2003-01-31
This is a summary of traffic on the `python-dev mailing list`_ from
January 16, 2003 to January 31, 2003. It is intended to inform the
wider Python community of on-going developments on the list that might
be of interest. To comment on anything mentioned here, just post to
firstname.lastname@example.org or comp.lang.python with subject line
delineating what you discussing. All python-dev members are interested
in seeing ideas discussed by the community, so don't hesitate to take
a stance on something. And if all of this really interests you then
get involved and join python-dev!
This is the tenth summary written by Brett Cannon (double digits,
All summaries are archived at http://www.python.org/dev/summary/ .
Please note that this summary is written using reStructuredText_ which
can be found at http://docutils.sf.net/rst.html . Any unfamiliar
punctuation is probably markup for reST_; you can safely ignore it
(although I suggest learning reST; its simple and is accepted for PEP
markup). Also, because of the wonders of programs that like to
reformat text, I cannot guarantee you will be able to run the text
version of this summary through Docutils_ as-is unless it is from the
original text file.
.. _python-dev mailing list:
.. _Docutils: http://docutils.sf.net/
.. _reStructuredText: http://docutils.sf.net/rst.html
To make the Summaries more thorough I have decided to make a list of
threads that I have decided not to summarize and give my reasoning
behind why I decided to skip it which should also explain what the
thread is about. I doubt anyone will have complaints about doing
this, but if you do let me know. You can find this section entitled
"Skipped threads" at the end of the summary.
Some PyCon_ announcements to make. Registration is scheduled to start
next week. Also, the list of accepted papers is expected to be
announced on-time. The conference is shaping up and getting
organized. It should be a lot of fun *and* educational, so make sure
you come to PyCon_ !
.. _PyCon: http://www.python.org/pycon/
`Adding Japanese Codecs to the distro`__
MA Lemburg brought up a patch on SourceForge by Hisao SUZUKI (I am
assuming the capitalization of the last name is a Japanese thing so I
will stick with it in the summary) to add "codecs for the Japanese
encodings EUC-JP, Shift_JIS and ISO-2022-JP" and donate the code to
the `Python Software Foundation`_. MAL's reason for wanting to use
these codecs over the current ones most commonly used with Python
(written by Tamito KAJIYAMA whose codecs can be found at
http://www.asahi-net.or.jp/~rd6t-kjym/python/ ) was that Hisao's were
smaller and written in pure Python.
Martin v. Löwis thought it was fine to add the codecs but thought
Tamito's should be the defaults if any codecs were added to Python.
His reasoning was that they have been in active development for a
while and thus have been independently verified, in a way, to be
correct. He also didn't like the "absence of the cp932 encoding in
Suzuki's codecs" since the "suggestion to equate this to "mbcs" on
Windows is not convincing". He also thought it would be best to add
the C version only. He also suggested "that it might be more
worthwhile to expose platform codecs, which would give us all CJK
codecs on a number of major platforms, with a minimum increase in the
size of the Python distribution, and with very good performance".
In response to Martin's comments, MAL thought that the benefit of the
Python versions of the codecs was that they were easier to modify. He
suggested that the C version then be made available to download as a
separate entity (which apparently has been suggested multiple times).
As for the independent verification, Hisao built his based on Java's
codecs which MAL thought was pretty good verification that they should
work. MAL agreed that exposing more platform codecs would be good.
Martin didn't go for the "easier editing" argument. He noted that
since the table was autogenerated you would need to know the algorithm
that made the table in order to be able to edit it.
Hye-Shik Chang responded with the support of the C version since it
allows for much easier interprocess communication. It also beat the
Python version when it came to memory consumption by a large margin.
Guido asked how Tamito would feel about adding these codecs, whether
both sets outputted the same, and whether Tamito's codecs would still
be preferred by people doing a lot of Japanese work.
Martin reponded that he didn't think they produced the same result and
that people would continue to use JapaneseCodecs (Tamito's codecs) as
long as Python didn't include the cp932 codec.
Barry Warsaw commented that Mailman used Tamito's codecs and no one
has ever complained. He said he would love to see one of the codecs
included in Python. Apparently their tend to be license issues with
the various Asian codecs. The KorenCodecs_ (or KoCo) are licensed
under LGPL, but Hye-Shik Chang said he would "like to make an essence
of KoreanCodecs in PSF License if python needs it".
Atsuo Ishimoto voted for Tamito's codecs. He said that the Japanese
community would continue to use them regardless of what went into
Python. And in regards to the question of maintaining the codecs,
Atsuo said the Japanese Python community would be willing to help
Tamito with his but did not expect that kind of support for Hisao's
codecs (Hisao has volunteered to maintain his codecs, though).
MAL pointed out that "Tamito's codecs have an installed size of 1790kB
while Hisao's codecs are around 81kB" and that was an issue. Martin
said that it was only 690kB if you only counted the C version. The
issue of size became a major point. It was pointed out that Tamito's
covered more codecs and being in C meant it only needed to be loaded
in memory once for interprocess use.
Tamito chimed in finally and commented that he was busy and would not
be able to maintain the codecs until he graduated from graduate
school. MAL suggested that he start maintaining it when he had the
time and Tamito agreed.
I am not sure where the situation stands as of this moment.
.. _Python Software Foundation: http://www.python.org/psf/
.. _KorenCodecs: http://sf.net/projects/koco
`make install failing with current cvs`__
Jack Jansen was having issues with ``make install`` because he had
various packages in site-python that had inconsistent tab usage and
thus was raising a TabError during the ``compileall()`` step. Jack
asked if site-packages could either be skipped by this step or at
least not lead to the abortion of the install. All of this was from a
change in ``compileall()`` that caused it to exit with a non-zero
value if any errors were raised (although it continued to run). That
feature was left in; the Makefile was modified so as to skip
`logging package -- rename warn to warning?`__
Guido said that he would "like to change 'warn' to 'warning' (and WARN
to WARNING)" in the logging_ package. His argument that nothing else
was a verb in the package.
Vinay Sajip (who wrote the logging package) said he was fine with the
change, but warned it would break existing code that already used the
package. He suggested putting both names in with a warning that
``warn`` was deprecated. This was shot down since a new package does
not need to start with anything deprecated.
Then the discussion of whether to ditch fatal/FATAL since they are
synonyms for crictical/CRITICAL came up. Guido said the reverse
should happen; keep FATAL and ditch CRITICAL (for the rest of this
summary I will only refer to the capitalized version to keep things
simple). Some opposition came up, holding the view that CRITICAL was
closer to the truth. Vinay suggested SEVERE as a replacement. Guido
said it didn't "tickle" his "fancy like fatal/FATAL does"; CRITICAL
was okay if no agreed upon replacement could be found. A quick
grepping of the package by me shows that CRITICAL is staying as well
was WARN (will most likely not be documented, though, so don't use it
for new code).
.. _logging: http://www.python.org/dev/doc/devel/lib/module-logging.html
`sys.exit and PYTHONINSPECT`__
Kevin Altis discovered that invoking the interpreter with the ``-i``
argument does not prevent the interpreter from exiting if SystemExit
is raised (``sys.exit()`` will raise the exception). He thought it
would be good if ``-i`` would override even the SystemExit exception.
`Bug #670311`_ was created for this, but no patch has been written yet
(anyone care to step up and do this?).
.. _bug #670311: http://sourceforge.net/tracker/index.php?func=detail&aid=670311&group_id=5470&atid=105470
`disable writing .py[co]`__
- `Proto-PEP regarding writing bytecode files
In the thread `Parallel pyc construction`_ (as covered in the last
summary), Paul Dubois brought up how he would like to be able to
disable the writing of .py[co] files. Well, this led to a long
discussion that culminated into the creation of `PEP 304`_ by Skip
Montanaro. If this topic interests you then read the PEP.
.. _Parallel pyc construction:
.. _PEP 304: http://www.python.org/peps/pep-0304.html
`Re: GadflyDA in core? Or as add-on-product?`__
The idea was proposed to add Gadfly_ to the stdlib. Two issues came
up about doing this. One was that it would require having to deal
with another license. Aaron Watters (the original author of Gadfly)
was emailed to ask if he would be willing to donate the code to the
`Python Software Foundation`_, but he did not respond (at least to the
The other issue was the use of kjbuckets_. Guido was -1 on letting it
into the stdlib because he had "heard it's some of .the hairiest C
code ever written". But Richard Jones said that Anthony Baxter is
working on removing the dependency on kjbuckets by rewriting the code
using the Sets_ module introduced in Python 2.3.
As of this writing the decision as to whether to add Gadfly has been
put on hold until both of the above issues are resolved.
.. _Gadfly: http://gadfly.sourceforge.net/
.. _Sets: http://www.python.org/dev/doc/devel/lib/module-sets.html
.. _kjbuckets: http://starship.python.net/crew/aaron_watters/kjbuckets/
`Mixed-type datetime comparisons`__
Tim Peters sent an email to the list saying that he had made changes
to the datetime_ type so that it returned NotImplemented if the thing
being compared to had a ``timetuple()`` method so as to allow other
implementations to provide the functionality.
He also mentioned how you still can't compare datetimes and
timedeltas. This caused MA Lemburg to ask why not. Tim said it just
wouldn't make any sense since they don't even measure time in the same
units. Tim ended on saying that if MAL and Fredrik Lundh could come
up with a good proposal Tim would get it in, otherwise his time on
datetime for Python 2.3 is spent.
.. _datetime: http://www.python.org/dev/doc/devel/lib/module-datetime.html
Raymond Hettinger checked in his itertools_ module into the sandbox
for testing and asked for feedback. He got it and has subsequently
checked the module into the stdlib.
.. _itertools: http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/python/python/dist/src/Modules/itertoolsmodule.c
`Idea for avoiding exception masking`__
Raymond Hettinger discovered that "trapping an exception (a TypeError
for a mutable argument passed to a dictionary) resulted in masking
other errors that should have been passed through (potential
TypeErrors in the called iterator for example)". Raymond proposed a
new function named PyErr_FormatAppend that would append the extra
info. Ka-Ping Yee suggested adding the original exception to the new
exception as an attribute. This was generally viewed as a good
solution. Questions of how to store traceback information and how to
handle this in the C code has yet to be resolved.
`Extended Function syntax`__
- `Property syntax <http://mail.python.org/pipermail/python-dev/2003-January/032591.html>`__
- `thunks (for all the fish)
- `question??? <http://mail.python.org/pipermail/python-dev/2003-January/032663.html>`__
- `Syntax-wise <http://mail.python.org/pipermail/python-dev/2003-January/032669.html>`__
- `How about a meta-reserved word?
This threads wins the award for longest thread summarized here (and
possibly ever for a summary written by me). Fair warning if you
decide to read the actual thread.
Also, none of this applies to Python 2.3; Guido promised syntactic
stability for this next release and you will get it.
Guido remembered that a proposal for extending the syntax of Python to
make using things such as ``property()``, ``staticmethod()``, etc.
much easier and wanted a reminder on where more info was. The
suggeted syntax was::
def name(arg, ...) [expr1, expr2, expr3, ...]:
where ``expr, ...`` would be evaluated like ``name =
expr3(expr2(expr1(name)))``. Michael Hudson wrote up a patch which
can be found at http://starship.python.net/crew/mwh/hacks/meth-syntax-sugar-3.diff
with the original python-dev thread on this at
All of this led to an explosion of other syntax suggestions. One that
garnered some support was to make something like::
def Foo.bar(self, a, b, c):
work by basically making a def statement work like
``Foo.bar=new.function(CODE, GLOBS, 'Foo.bar')``. If properties were
made assignable then you could just use this syntax to assign to a
property you instantiated. People also came up with metaclass
implementations of some things (which Guido didn't like because they
"all abuse the class keyword for something that's definitely not a
An idea that Walter Dörwald suggested was::
"""Doc string for myprop."""
def __set__(self, arg):
Guido's objection was that it turned property into a keyword. But he
admitted that a new keyword would be okay if an elegant solution came
Guido then made the suggestion of::
foo = property:
This also garnered some support. The problem with this is that it
would require the parser to be able to go from '"expression parsing
mode" to "block parsing mode"' in a new way. But Guido seemed to
solve it. It would also allow the generalization of this to something
along the lines of::
v = e: # Possibility for adding args -- v = e:(x, y):
S # Creates a thunk
which would be equivalent to::
v = e(T) # T is a thunk created from S
None of this is meant to replace the suggested [expr, ...] syntax that
started this whole thread.
Another syntactic suggestion was::
def foo as property:
def __set__(self, x):
Which seemed to grab a lot of people's fancies. This would allow for
"... as class", "... as generator", etc.
But the problem with all of these proposals is how to deal with
namespaces. Should, for instance, the thunks Guido suggested have
their own namespace or use the one of their parent? Should their be
only one type of thunk or multiple types with different scoping rules
based on the situation? The namespace issue (especially for thunks)
is still playing out.
`Capabilities in Python`__
This thread actually came out of the whole property/thunk thing
summarized directly above but was so tangential that I thought it
deserved its own summary.
Ben Laurie had apparently suggested that capabilities be added to
Python. Jeremy Hylton gave a pretty good description of a capability
as "a ticket. The ticket is good for some event and possession of the
ticket is sufficient to attend the event"; limit abilities of objects
based on what capabilities you possess. The problem is that Python's
introspection lets you see everything and thus you can get around
restrictions; you can get into the event by sneaking out back and
crawling under the fence all without having a ticket. Jeremy
mentioned Zope's proxy which fully wraps an object and forces all
interaction through the proxy.
Then Ka-Ping Yee stepped up to discuss the topic. He made the point
that "creating a capability is equivalent to creating an object --
which you can only do if you hold the constructor". Ping said that
"To build a capability system, all you need to do is to constrain the
transfer of object references such that they can only be transmitted
along other object references. That's all." In order to pull this
off you would need to restrict access to only the declared interface
of an object and have "no global namespace of modules". In other
words have something like a private declaration for things and get rid
of ``sys.modules``. Ping suggested coming up with a "secure-mode"
Python where these restrictions would be turned on. Neil Schemenauer
liked this idea.
`test_logging failing on Windows 2000
Since it dealt with a bug that received a patch I didn't worry about
`PyConDC sprints <http://mail.python.org/pipermail/python-dev/2003-January/032216.html>`__
Meant for the people on python-dev directly, so no point in telling
the general community about it.
`String method: longest common prefix of two strings
Didn't go anywhere; Guido said he doesn't want to add every useful
thing as a string method since there are already so many.
`very slow compare of recursive objects
Discussed a patch about recursive compares. Basically led to no
change and dealt with how to make a tuple recursive.
`test_email always supposed to be skipped?
Glitch in Makefile.pre.in which got fixed.
`extending readline functionality (patch)
Someone sending a patch directly to python-dev; big no-no! Use
SourceForge_ for any all patches.
`Re: [Python-checkins] python/dist/src Makefile.pre.in,1.111,1.112
No one ever responded to the email; problem was probably solved.
`Cookie.py too strict
Barry Warsaw wanted to make the Cookie_ module less strict in
acceptance. Michael Chermside suggested adding an argument to be able
to specify whether the acceptance of data should be strict or not.
`HTMLParser patches <http://mail.python.org/pipermail/python-dev/2003-January/032469.html>`__
Mentions two patches for HTMLParser_ to fix some parsing problems.
`Name space pollution (fwd)
Someone on `c.l.py`_ didn't like the naming of a function
``destructor`` in the core because it is such a common name and thus
can clash with other code. Guido said submit a patch or use some
`logging package -- spurious package contents
Guido didn't like the config file for the logging_ package nor the
extra handlers. It was agreed to ditch the config file but keep the
`logging package -- documentation
Better docs for the logging_ package were uploaded and are ready to
`Re: [Zope3-dev] PosixTimeZone tzinfo implementation
Single email mentioning the tm_gmtoff attribute of the datetime type.
The ossaudiodev_ module was hanging in tests. It has been disabled
`Looking for a Windows bsddb fan
Tim Peters upgraded the Windows distribution to berkeleydb 4.1.25;
doing so caused a huge amount of test failures. Turned out they were
race conditions in the tests inherit in such complicated tests.
`Extension modules, Threading, and the GIL
Mention of how the GIL puts a cramp into writing PyGTK_. This thread
started last month (
`the new 2.3a1 settimeout() with httplib and SSL
There was a problem with the new timeout mechanism in socket_ and
SSL. There is a a patch at http://www.python.org/sf/676472 to fix the
`non-blocking sockets and sendall
Brian Ellin noticed that ``socket.sendall()`` and non-blocking
sockets don't work together.
`Re: [Python-checkins] python/dist/src/Lib/bsddb
Skip Montanaro asking whether bsddb185 should become "a fallback to
`xmlparse.c no longer compiles on Windows
Tim Peters discovered `xmlparse.c`_ had some #define lines for the
non-existent case of no ``memmove()`` function.
`fixing traceback.extract_stack() line numbers
Greg Klanderman noticed that ``traceback.extract_stack()`` only gives
the first line of the method and not of the actual line that caused an
`python2.3 on m68k-nommu uClinux, really slow
Brad Clements got Python working on an m68k processor and performance
was horrible. He asked if anyone had any ideas on how to speed it up.
`native code compiler? (or, OCaml vs. Python)
Someone asked if Python was ever going to have a native code
compiler. The answer is "if you want to write one" and to ask the
question nicely. It also became a debate over how difficult a native
code compiler would be.
Skip Montanaro sent an email about a security hole found in
``os.exec*p()`` method that was patched back in August. It has
subsequently been back-patched to 2.1.
`map, filter, reduce, lambda
Andrew Koenig commenting on the discussion from the `last summary`_.
`Global interpreter lock/import mechanism
Joerg Budischewski asked some questions about the proper way of doing
some things in a C extension.
`Should Cygwin Python use --enable-runtime-pseudo-reloc?
Title of this thread makes what it is about obvious.
`New PEP 306 needs proof reading.
Another thread whose content is obvious by the title.
`StringIO not an iterator?
Misunderstanding initially. Guido then suggested that (c?)StringIO
become its own iterator which became a bug report.
`SF patch #677429 (PEP293 callbacks)
Walter Dörwald asking for someone to look over a patch since Martin
v. Löwis in on vacation (and this explains why I have not been
bringing up the character palette so much in this summary for
inserting umlauts =).
Someone asking an improper question on the list (Mailman lists this
in February, but I am on Pacific time so I say it is in January =).
`PEP 42: sizeof(obj) builtin
Raymond Hettinger asked if people still wanted ``sizeof()`` in
Python. One person said yes. The difficulty of doing this correctly
was also pointed out along with the suggestion that if this function
is written it be a part of the ``sys`` module.
`PEP 305 - CSV File API
"A new PEP (305), "CSV File API", is available for reader feedback".
`New version of PEP 304
A new version of PEP 304 is up.
Skip Montanaro had a question about returning when a possible error
was signalled on an import.
.. _SourceForge: http://www.sf.net/projects/python
.. _Cookie: http://www.python.org/dev/doc/devel/lib/module-Cookie.html
.. _c.l.py: http://groups.google.com/groups?q=comp.lang.python&ie=ISO-8859-1&hl=en&btnG=Google+Search
.. _ossaudiodev: http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/python/python/dist/src/Modules/ossaudiodev.c
.. _setup.py: http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/python/python/dist/src/setup.py
.. _PyGTK: http://www.daa.com.au/~james/pygtk/
.. _HTMLParser: http://www.python.org/dev/doc/devel/lib/module-HTMLParser.html
.. _xmlparse.c: http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/python/python/dist/src/Modules/expat/xmlparse.c
.. _last summary: http://www.python.org/dev/summary/2003-01-01_2003-01-15.html
.. _socket: http://www.python.org/dev/doc/devel/lib/module-socket.html