Mailman 3 April 2007 - Python-Dev

new subscriber looking for grunt work
by Sergio Mion 17 Apr '07

17 Apr '07

Hello All, I'll be as brief as possible. The welcome message to this list suggested that I post a brief introduction of myself, so here it goes. I've been programming for about 10 years now (7 professionally). I would rank myself as a moderate programmer always looking to improve, and would like to help on this project in whatever way I can. I'll be trolling for grunt work and any documentation that needs to be done while I get the hang of things around here. Thanks for your patience. Sergio Mion

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Changes to decimal.py
by Raymond Hettinger 17 Apr '07

17 Apr '07

Now that the checkin is done, I don't think it needs to be reverted. But, in general, we should probably abstain from making wholesale revisions that add zero value for the users. The stylistic change from: ValueError, 'foo' ValueError('foo') is fine. Changing MockThreading to subclass from object though borders on being a semantic change and should be done with care. In this particular case, I see no harm in it, but then I haven't tested it on a Py2.3 build with threading disabled. As promised in the decimal.py header, the spec updates should all be considered as bugs and backported at some point after they are fully tested and we're happy with them all around. Also, as promised, the module should continue to run on Py2.3. For the most part, many of the new operations can be implemented in terms of the existing ops or in terms of the support functions that we already use internally. Ideally, you can refactor common code while leaving almost all of the exisiting algorithm implementation code untouched. The spec's choice of new method names is unfortunate. You'll have to come-up with something better than copy() and class(). FWIW, I think the new decimal development should probably be done in a branch off of the current head. That way, you can check-in at will and get feedback from everyone without risking the integrity of the head. If you want to discuss anything during development, I'm usually available on AOL instant messaging with the screename: raymondewt Likewise, consider soliciting Tim's input on how to implement the ln() operation. That one will be tricky to get done efficiently and correctly. Raymond

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Access to Python SVN
by Travis E. Oliphant 17 Apr '07

17 Apr '07

I'd like to ask for access to Python SVN so that I can keep the PEP 3118 up to date as well as to eventually make the changes needed for implementing the extended buffer protocol. I have quite a bit of experience with the Python C-API and understand many parts of the code base fairly well (though I would not claim to be an expert on all of it). I promise to only adjust the PEP until such time as patches to implement the extended buffer protocol are approved. I will email my public SSH key to the appropriate place. Thank you very much, -Travis Oliphant

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Re: [Python-Dev] [Python-checkins] r54805 - python/branches/release25-maint/Lib/test/test_pty.py
by Barry Warsaw 16 Apr '07

16 Apr '07

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Apr 13, 2007, at 4:58 PM, Martin v. Löwis wrote: >> I don't know, maybe it is. This one's extremely low risk as it only >> affects certain platforms when test_pty is run verbosely. But if it >> ain't cool, I'll back it out and re-apply after 2.5.1 final. > > Please back it out. If there are changes to the branch, we would have > to create another release candidate (IMO). I see Neal did already... thanks Neal. I was away for most of the weekend. Cheers, - -Barry -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (Darwin) iQCVAwUBRiNj3XEjvBPtnXfVAQLgfQP+KVKtGkEzZpo8Bjhlo6w7zII5oQdo9pDy L18n2OjcJyAsz+Hgo4hkel6W+O39o/lR0EtjohCUlfG92DTgyoUxGXc2g88LyT83 G4Gob2UBoqiWnsHpYjWFP6/HlAcr6nUXa6CGJqkyhzud6+c9ZsdfOIhDpZfyxh2x ZzH/D5f8D7M= =aI0k -----END PGP SIGNATURE-----

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Re: [Python-Dev] Python 2.5.1c1 pickle problem
by Raymond Hettinger 16 Apr '07

16 Apr '07

The pickle issue may be related to revision 53655 fixing a psuedo-bug (it was arguable whether current or prior behavior was most desirable). Will look at this more and will report back. Raymond

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my 2.5 checkins
by Kristján Valur Jónsson 16 Apr '07

16 Apr '07

Hello all. I made two checkins to the 25 maintainance branch before Martin kindly pointed out to me that it is frozen. These are quite simple fixes to real crashes I have experienced. The fix in frameobject.c will be necessary if you work with opcodes > 128, which we routinely do at CCP J. Security through opcode randomization.... Anyway, just let me know if you like me to roll them back. Cheers, Kristján

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Some new additions to functools
by SevenInchBread 16 Apr '07

16 Apr '07

So I've cooked up some very simple functions to add to functools - to expand it into a more general-purpose module. def cat(x): return x class nullfunc(object): def __call__(self, *args, **kargs): return self def __getattr__(self, name): return getattr(None, name) def multimap(func, seq, n=2): assert n > 0, "n must be positive" if n == 1: return map(func, seq) else: return map(lambda x: multimap(func, x, n-1), seq) def multifilter(func, seq, n=2): return multimap(lambda x: filter(func, x), seq, n-1) def multireduce(func, seq, n=2): return multimap(lambda x: reduce(func, x), seq, n-1) In an expression, cat achieves the effect of doing nothing - which makes it a nice default value for some filter-like functions. It's not a huge improvement - lambda x: x is almost as trivial to define, but I think it would be nice to have a standard identity function that all of Python could recognize. nullfunc is a function that *chomps* away at its input while otherwise retaining the properties of None - much like the recently proposed callable None - except not as disasterous to existing practices and potentially more useful as an optional behavior. This is something that cannot be as quickly implemented as the cat function. multimap is a multi-dimensional mapping function that recursively decends a sequence and applies a function to the data within. multifilter is a multi-dimensional filter function that recursively descends a sequence and applies a function to the data within multireduce - well... you get the idea A better place to put some of these functions might be __builtin__, so you don't have to waste time importing something as basic as cat. -- "What's money? A man is a success if he gets up in the morning and goes to bed at night and in between does what he wants to do." ~ Bob Dylan

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Re: [Python-Dev] functools additions
by SevenInchBread 16 Apr '07

16 Apr '07

>> Do you have commit access? What's your real name? I prefer to remain pseudonymous, and I don't have commit access. Yeah... they're not terribly useful - more or less there for the sake of being there. Batteries included and all that ...but now I've got a more useful idea for a function wrapper around predicate functions to make them a little more functionally inclined. Something like....... @predicate def hasnext(x): return hasattr(x, "next") @predicate def hasiter(x): return hasattr(x, "__iter__") isiterable = hasnext or hasiter #or/and/not operators construct new predicate functions isEmptyIterable = isiterable and not predicate(bool) isgenerator = isiterable and (lambda x: hasattr(x, "send") and hasattr(x, "throw")) filter(isgenerator or callable, SomeSequence) -- "What's money? A man is a success if he gets up in the morning and goes to bed at night and in between does what he wants to do." ~ Bob Dylan

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functools additions
by SevenInchBread 16 Apr '07

16 Apr '07

So.... if it's alright with the privledged folk - I'd like to commit these minor (and probably non-controversial) additions to the functools module. def cat(x): return x def multimap(func, s, n=2): assert n > 0, "n must be positive" return (map(func, seq) if n == 1 else map(lambda x: multimap(func, x, n-1), seq)) def multifilter(func, s, n=2): return multimap(lambda x: filter(func, x), s, n-1) def multireduce(func, s, n=2): return multimap(lambda x: reduce(func, x), s, n-1) class nullfunc(object): def __call__(self, *a, **k): return self def __getattr(self, name): return getattr(None, name) cat is a generic identity function - useful for some higher-order functions to specify a function that "does nothing". multimap, multifilter, and multireduce, are all multi-dimensional versions of map, filter, and reduce. nullfunc is a special callable object that emulates the failed callable None proposal - which wasn't really a good idea, but would have been more useful as a different object apart from None. you could probably even put cat in __builtins__ - so you don't need to waste effort importing such a trivial function. --. "What's money? A man is a success if he gets up in the morning and goes to bed at night and in between does what he wants to do." ~ Bob Dylan

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Re: [Python-Dev] Python 2.5.1c1 pickle problem
by Ralf W. Grosse-Kunstleve 15 Apr '07

15 Apr '07

Hi Raymond, Thanks for the detailed explanation! > I'm not sure what your code was doing where the bugfix would cause > breakage. If its __getitem__() override returned a meaningful value > for each element in obj.keys(), then it should have worked fine. Of > course, if it was raising an exception or triggering a side-effect, > then one could argue that the bugfix was working as intended by > allowing the subclasser to affect how the base class goes about its > business. It wasn't actually my own code, but that of a colleague. His __getitem__() override is below. It fails because __getitem__() is called with the wrong type of argument (plain int instead of a list of atoms). I'm not sure it presents a convincing use case. I would have used composition instead of inheritance in the same situation. I don't feel competent to join the discussion about the changes in the pickling behavior, but I feel quite strongly that such a change should not be introduced in a bug-fix release. Ralf def __getitem__(self, atoms): LIST = [] for atom in atoms: attr = 'index' if hasattr(atom, 'unique_index'): attr = 'unique_index' LIST.append(getattr(atom, attr)) key1 = tuple(LIST) LIST.reverse() key2 = tuple(LIST) rc = None try: rc = dict.__getitem__(self, key1) except KeyError, e: pass try: rc = dict.__getitem__(self, key2) except KeyError, e: pass return rc __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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