Mailman 3 April 2009 - Python-Dev

Python 2.6.2 final
by Barry Warsaw 13 Apr '09

13 Apr '09

I wanted to cut Python 2.6.2 final tonight, but for family reasons I won't be able to do so until Monday. Please be conservative in any commits to the 2.6 branch between now and then. bugs.python.org is apparently down right now, but I set issue 5724 to release blocker for 2.6.2. This is waiting for input from Mark Dickinson, and it relates to test_cmath failing on Solaris 10. If Mark fixes that, he's welcome to commit it, otherwise I will remove the release blocker tag on the issue and release 2.6.2 anyway. Plan on me tagging 2.6.2 final Sunday evening. Cheers, -Barry

2 2

Evaluated cmake as an autoconf replacement
by Jeffrey Yasskin 12 Apr '09

12 Apr '09

I've heard some good things about cmake — LLVM, googletest, and Boost are all looking at switching to it — so I wanted to see if we could simplify our autoconf+makefile system by using it. The biggest wins I see from going to cmake are: 1. It can autogenerate the Visual Studio project files instead of needing them to be maintained separately 2. It lets you write functions and modules without understanding autoconf's mix of shell and M4. 3. Its generated Makefiles track header dependencies accurately so we might be able to add private headers efficiently. However, after trying it out during PyCon and looking over the previous attempt at <http://mail.python.org/pipermail/python-dev/2007-July/073912.html>, I can't recommend switching to it. A. It has no equivalent of autoheader, so we'd have to maintain pyconfig.h.in by hand. B. It does not allow the CMakeLists.txt file control the --help output. This appears to be an intentional decision (http://www.cmake.org/pipermail/cmake-promote/2006-May/000095.html). To replace it, they have an interactive mode (which asks you about each possible option) and a -LH flag (which runs the whole configure process and then tells you about the flags you could have set if you knew about them). C. It does not allow the CMakeLists.txt file to see the command line, so we can't stay backward compatible with the configure script, and we'd have to replace flags like --with-pydebug with -Dpydebug:bool=true. We could write a separate configure script to mitigate this and the previous problem, but we'd have to keep that in sync with CMakeLists.txt manually. D. It doesn't have an expression language, so to replace ac_md_system=`echo $ac_sys_system | tr -d '[/ ]' | tr '[[A-Z]]' '[[a-z]]'` you have to write: string(REGEX REPLACE "[/ ]" "" ac_md_system ${ac_sys_system}) string(TOLOWER ${ac_md_system} ac_md_system) So, at the very least, it doesn't look like a big enough win to justify switching, and may not be a win at all. The other popular configure+make replacement is scons. The biggest objection to scons before even looking at it is that it requires a working Python interpreter in order to build Python, causing a bootstrap problem. However, Brett Cannon and I talked, and we think this is surmountable. First, nearly every desktop system comes with a Python interpreter, which would avoid the bootstrap for ordinary development. Second, we need a cross compilation story anyway for embedded systems, and the same mechanism could be used to get Python onto a new desktop platform. Third, Jython and IronPython are pretty mature and either can run scons now or should be able to run it after some relatively easy tweaks. They could be used to build CPython on a new platform. I don't intend to look into scons myself any time soon, but I'd be interested in anyone's experiences who does try it. Jeffrey

16 41

Needing help to change the grammar
by Harry (Thiago Leucz Astrizi) 12 Apr '09

12 Apr '09

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello everybody. My name is Thiago and currently I'm working as a teacher in a high school in Brazil. I have plans to offer in the school a programming course to the students, but I had some problems to find a good langüage. As a Python programmer, I really like the language's syntax and I think that Python is very good to teach programming. But there's a little problem: the commands and keywords are in english and this can be an obstacle to the teenagers that could enter in the course. Because of this, I decided to create a Python version with keywords in portuguese and with some modifications in the grammar to be more portuguese-like. To this, I'm using Python 3.0.1 source code. I already read PEP 306 (How to Change Python's Grammar) and changed the suggested files. My changes currently are working properly except for one thing: the "comp_op". The code that in english Python is written as "is not", in portuguese Python shall be "não é". Besides the translations to the words "is" and "not", I'm also changing the order in which they appear letting "not" before "is". It appears to be a simple change, but strangely, I'm not being able to perform it. I already made correct modifications in Grammar/Grammar file, the new keywords already appear in Lib/keyword.py and I also changed the function validate_comp_op in Modules/parsermodule.c: static int validate_comp_op(node *tree) { (...) else if ((res = validate_numnodes(tree, 2, "comp_op")) != 0) { res = (validate_ntype(CHILD(tree, 0), NAME) && validate_ntype(CHILD(tree, 1), NAME) && (((strcmp(STR(CHILD(tree, 0)), "não") == 0) && (strcmp(STR(CHILD(tree, 1)), "é") == 0)) || ((strcmp(STR(CHILD(tree, 0)), "não") == 0) && (strcmp(STR(CHILD(tree, 1)), "em") == 0)))); if (!res && !PyErr_Occurred()) err_string("operador de comparação desconhecido"); } return (res); } I also looked in the other files proposed in the PEP but I didn't find in them nothing that I recognized as needing changes. But when I type "make" to compile the new language, the following error appears in Lib/encodings/__init__.py (which I already translated to the portuguese Python): harry@skynet:~/Python-3.0.1$ make Fatal Python error: Py_Initialize: can't initialize sys standard streams File "/home/harry/Python-3.0.1/Lib/encodings/__init__.py", line 73 se entry não é _unknown: ^ SyntaxError: invalid syntax The comp_op doesn't work! I don't know more what to change. Perhaps there's some file that I should modify, but I didn't paid attention enough in it... Please, anybody has some idea of what should I do? Thanks a lot. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQFJ3/eTmNGEzq1zP84RAh5vAJ492eVFgbR5KCCJNdTJOIR/Xtfb0ACdE0NG Yxnxmo9yjOL6H8J93nPBcJs= =6VLu -----END PGP SIGNATURE-----

6 6

Re: [Python-Dev] [Python-ideas] Proposed addtion to urllib.parse in 3.1 (and urlparse in 2.7)
by Mart Sõmermaa 12 Apr '09

12 Apr '09

On Sun, Apr 12, 2009 at 3:23 PM, Jacob Holm <jh(a)improva.dk> wrote: > Hi Mart > > >>> add_query_params('http://example.com/a/b/c?a=b', b='d', foo='/bar') >> 'http://example.com/a/b/c?a=b&b=d&foo=%2Fbar < >> http://example.com/a/b/c?a=b&b=d&foo=%2Fbar>' >> >> Duplicates are discarded: >> > > Why discard duplicates? They are valid and have a well-defined meaning. The bad thing about reasoning about query strings is that there is no comprehensive documentation about their meaning. Both RFC 1738 and RFC 3986 are rather vague in that matter. But I agree that duplicates actually have a meaning (an ordered list of identical values), so I'll remove the bits that prune them unless anyone opposes (which I doubt). >> But if a value is given, the empty key is considered a duplicate (i.e. the >> case of a&a=b is considered nonsensical): >> > > Again, it is a valid url and this will change its meaning. Why? I'm uncertain whether a&a=b has a meaning, but don't see any harm in supporting it, so I'll add the feature. >> >>> add_query_params('http://example.com/a/b/c?a', a='b', c=None) >> 'http://example.com/a/b/c?a=b&c <http://example.com/a/b/c?a=b&c>' >> >> If you need to pass in key names that are not allowed in keyword >> arguments, >> pass them via a dictionary in second argument: >> >> >>> add_query_params('foo', {"+'|äüö": 'bar'}) >> 'foo?%2B%27%7C%C3%A4%C3%BC%C3%B6=bar' >> >> Order of original parameters is retained, although similar keys are >> grouped >> together. >> > > Why the grouping? Is it a side effect of your desire to discard > duplicates? Changing the order like that changes the meaning of the url. > A concrete case where the order of field names matters is the ":records" > converter in http://pypi.python.org/pypi/zope.httpform/1.0.1 (a small > independent package extracted from the form handling code in zope). It's also related to duplicate handling, but it mostly relates to the data structure used in the initial implementation (an OrderedDict). Re-grouping is removed now and not having to deal with duplicates simplified the code considerably (using a simple list of key-value tuples now). If you change it to keep duplicates and not unnecessarily mangle the field > order I am +1, else I am -0. Thanks for your input! Changes pushed to github (see the updated behaviour there as well): http://github.com/mrts/qparams/blob/4f32670b55082f8d0ef01c33524145c3264c161… MS

3 2

Possible py3k io wierdness
by brian＠sweetapp.com 12 Apr '09

12 Apr '09

Hey, I noticed that the call pattern of the C-implemented io libraries is as follows (translating from C to Python): class _FileIO(object): def flush(self): if self.__IOBase_closed: raise ... def close(self): self.flush() self.__IOBase_closed = True class _RawIOBase(_FileIO): def close(self): # do close _FileIO.close(self) This means that, if a subclass overrides flush(), it will be called after the file has been closed e.g. >>> import io >>> class MyIO(io.FileIO): ... def flush(self): ... print('closed:', self.closed) ... >>> f = MyIO('test.out', 'wb') >>> f.close() closed: True It seems to me that, during close, calls should only propagate up the class hierarchy i.e. class _FileIO(object): def flush(self): if self.__IOBase_closed: raise ... def close(self): _FileIO.flush(self) self.__IOBase_closed = True I volunteer to change this if there is agreement that this is the way to go. Cheers, Brian

7 15

PyCFunction_* Missing
by Campbell Barton 11 Apr '09

11 Apr '09

Hi, Just noticed the new Python 2.6.2 docs now dont have any reference to * PyCFunction_New * PyCFunction_NewEx * PyCFunction_Check * PyCFunction_Call Ofcourse these are still in the source code but Im wondering if this is intentional that these functions should be for internal use only? -- - Campbell

2 1

issue5578 - explanation
by Maciej Fijalkowski 11 Apr '09

11 Apr '09

So. The issue was closed and I suppose it was closed by not entirely understanding the problem (or I didn't get it completely). The question is - what the following code should do? def f(): a = 2 class C: exec 'a = 42' abc = a return C print f().abc (quick answer - on python2.5 it return 42, on python 2.6 and up it returns 2, the patch changes it to syntax error). I would say that returning 2 is the less obvious thing to do. The reason why IMO this should be a syntax error is this code: def f(): a = 2 def g(): exec 'a = 42' abc = a which throws syntax error. Cheers, fijal

9 21

Test failures on Python 2.7 (trunk)
by Chris Withers 11 Apr '09

11 Apr '09

Hi All, Got these when running from checkout on Mac OS: Could not find '/Users/chris/py2k/Lib/test' in sys.path to remove it ... test test_asynchat produced unexpected output: ********************************************************************** error: uncaptured python exception, closing channel <test.test_asynchat.echo_client at 0x263a4b8> (<class 'socket.error'>:[Errno 9] Bad file descriptor [/Users/chris/py2k/Lib/asyncore.py|readwrite|107] [/Users/chris/py2k/Lib/asyncore.py|handle_expt_event|441] [<string>|getsockopt|1] [/Users/chris/py2k/Lib/socket.py|_dummy|165]) ...(lots of repeats of the above) ********************************************************************** test_asyncore test test_asyncore failed -- Traceback (most recent call last): File "/Users/chris/py2k/Lib/test/test_asyncore.py", line 144, in test_readwrite self.assertEqual(tobj.read, True) AssertionError: False != True ... test test_macostools failed -- Traceback (most recent call last): File "/Users/chris/py2k/Lib/test/test_macostools.py", line 90, in test_mkalias_relative macostools.mkalias(test_support.TESTFN, TESTFN2, sys.prefix) File "/Users/chris/py2k/Lib/plat-mac/macostools.py", line 40, in mkalias relativefsr = File.FSRef(relative) Error: (-35, 'no such volume') Should I expect these? If so, why? cheers, Chris

3 2

How do I update http://www.python.org/dev/faq?
by Chris Withers 11 Apr '09

11 Apr '09

Hi All, How do I update the faq on the website? This section: http://python.org/dev/faq/#how-to-test-a-patch ...could do with fleshing out from this discussion: http://mail.python.org/pipermail/python-dev/2009-March/086771.html ...and the link to: http://www.python.org/doc/lib/module-test.html ...still ends up at the 2.5.2 docs. cheers, Chris -- Simplistix - Content Management, Zope & Python Consulting - http://www.simplistix.co.uk

2 1

Test failure on Py3k branch
by Chris Withers 11 Apr '09

11 Apr '09

Hi All, Also got the following failure from a py3k checkout: test test_cmd_line failed -- Traceback (most recent call last): File "/Users/chris/py3k/Lib/test/test_cmd_line.py", line 143, in test_run_code 0) AssertionError: 1 != 0 Should I expect this or does someone owe beer? ;-) Chris

2 2