Mailman 3 April 2014 - Python-Dev

Incorrect behavior in str.format() method when padding with '\x00'
by John Tyree April 3, 2014

April 3, 2014

Hi all, Is there any particularly reason for the following behavior on both 2.7.6 and 3.4.0 ? >>> "{:\x00<5}".format(2) > '2 ' > >>> > "{:\x20<5}".format(2) > > '2 ' > >>> > "{:\x01<5}".format(2) > > '2\x01\x01\x01\x01' > >>> "{:\x00<5}".format(2) == > "{:\x20<5}".format(2) > > True > The docs say "If a valid *align* value is specified, it can be preceded by a *fill* character that can be any character and defaults to a space if omitted," so I'm inclined to call this a good old fashioned bug. -- John Tyree Scientific Software Developer Enthought, Inc. www.enthought.com

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libpython added to ABI tracker
by Andrey Ponomarenko April 3, 2014

April 3, 2014

Hi, The libpython library has been added to the ABI tracker: http://upstream-tracker.org/versions/python.html The page lists library versions and changes in API/ABI. -- Andrey Ponomarenko, NTC IT ROSA.

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Negative timedelta strings
by Steven D'Aprano April 2, 2014

April 2, 2014

There's a furious discussion going on at the python-list mailing list, about negative timedelta strings: py> str(timedelta(0, -1)) '-1 day, 23:59:59' This is documented. It's even documented as being "somewhat unusual". I found a tracker item for it, back in July 2010: http://bugs.python.org/issue9430 and that refers back to a discussion on #python-dev, but (as far as I know) that's not archived anywhere. I had a look on the python-dev mailing list around that time, and couldn't find anything. Does anyone remember the rationale for this behaviour? Is it open to debate or is it now cast in stone? (Personally, I'm not looking to reopen the debate, and if I did, it would be on python-ideas.) Any links to the earlier discussion would be helpful. Thanks, -- Steve

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pickle self-delimiting
by Charles-François Natali April 1, 2014

April 1, 2014

Hi, Unless I'm mistaken, pickle's documentation doesn't mention that the pickle wire-format is self-delimiting. Is there any reason why it's not documented? The reason I'm asking is because I've seen some code out there doing its own ad-hoc length-prefix framing. Cheers, cf

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Re: [Python-Dev] [Python-checkins] cpython (3.4): simplify check, since now there are only new-style classes
by Zachary Ware April 1, 2014

April 1, 2014

On Tue, Apr 1, 2014 at 1:21 PM, benjamin.peterson <python-checkins(a)python.org> wrote: > http://hg.python.org/cpython/rev/abb85902ce79 > changeset: 90090:abb85902ce79 > branch: 3.4 > parent: 90088:4a2dabac976d > user: Benjamin Peterson <benjamin(a)python.org> > date: Tue Apr 01 14:20:56 2014 -0400 > summary: > simplify check, since now there are only new-style classes > > files: > Lib/urllib/request.py | 7 ++----- > 1 files changed, 2 insertions(+), 5 deletions(-) > > > diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py > --- a/Lib/urllib/request.py > +++ b/Lib/urllib/request.py > @@ -511,9 +511,6 @@ > If any of the handlers passed as arguments are subclasses of the > default handlers, the default handlers will not be used. > """ > - def isclass(obj): > - return isinstance(obj, type) or hasattr(obj, "__bases__") > - > opener = OpenerDirector() > default_classes = [ProxyHandler, UnknownHandler, HTTPHandler, > HTTPDefaultErrorHandler, HTTPRedirectHandler, > @@ -524,7 +521,7 @@ > skip = set() > for klass in default_classes: > for check in handlers: > - if isclass(check): > + if instance(check, type): Should be isinstance, should it not? -- Zach

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Adding a readinto1 method to BufferedReader
by Nikolaus Rath April 1, 2014

April 1, 2014

Hello, The BufferedReader (and BufferedRWPair) classes both have a read1() method in addition to the regular read() method to bypass the internal buffer. This is quite useful if you need to do some buffered reading (e.g. to parse a header) followed by a lot of bulk data that you want to process as it streams in. However, the readinto() method does not have a corresponding readinto1() method. I would like to add this method. I have proposed a patch in http://bugs.python.org/issue20578. Are there any comments, objections, encouragements...? Best, -Nikolaus -- GPG encrypted emails preferred. Key id: 0xD113FCAC3C4E599F Fingerprint: ED31 791B 2C5C 1613 AF38 8B8A D113 FCAC 3C4E 599F »Time flies like an arrow, fruit flies like a Banana.«

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