Re: [Python-Dev] Semantics of __int__(), __index__()
Guido van Rossum, 04.04.2013 23:14: On Thu, Apr 4, 2013 at 1:50 PM, Tim Delaney wrote: I fall into: 1. int(), float(), str() etc should return that exact class (and operator.index() should return exactly an int). 2. It could sometimes be useful for __int__() and __index__() to return a subclass of int. So, for the int constructor, I would have the following logic (assume appropriate try/catch): def __new__(cls, obj): i = obj.__int__() if type(i) is int: return i return i._internal_value CPython can solve this in C using an unsafe cast, and the code that checks for allowable subclasses of int actually ensures such a cast will work. But it still feels wrong; __int__ should be expected to do the work. +1, that's why it's called __int__ (even if it returns a PyLong in Py3 ;) Stefan ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Slides from today's parallel/async Python talk
Hello, async.submit_work(func, args, kwds, callback=None, errback=None) How do you implement arguments passing and return value? e.g. let's say I pass a list as argument: how do you iterate on the list from the worker thread without modifying the backing objects for refcounts (IIUC you use a per-thread heap and don't do any refcounting). Correct, nothing special is done for the arguments (apart from incref'ing them in the main thread before kicking off the parallel thread (then decref'ing them in the main thread once we're sure the parallel thread has finished)). IIUC you incref the argument from the main thread before publishing it to the worker thread: but what about containers like list? How do you make sure the refcounts of the elements don't get deallocated while the worker thread iterates? More generally, how do you deal with non-local objects? BTW I don't know if you did, but you could probably have a look at Go's goroutines and Erlang processes. cf ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] relative import circular problem
+1. I was thinking along the same lines.
Allowing relative imports in import module [as X] statements.
If 'module' consists of pure dots, then as X is required.
Otherwise, if as X is not present, strip the leading dot(s) when assigning
the local name.
K
-Original Message-
From: Python-Dev [mailto:python-dev-
bounces+kristjan=ccpgames@python.org] On Behalf Of Richard
Oudkerk
Sent: 4. apríl 2013 16:26
To: python-dev@python.org
Subject: Re: [Python-Dev] relative import circular problem
How about having a form of relative import which only works for
submodules. For instance, instead of
from . import moduleX
write
import .moduleX
which is currently a SyntaxError. I think this could be implemented as
moduleX = importlib.import_module('.moduleX', __package__)
--
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Re: [Python-Dev] relative import circular problem
-Original Message- From: PJ Eby [mailto:p...@telecommunity.com] Sent: 4. apríl 2013 20:29 To: Guido van Rossum Cc: Kristján Valur Jónsson; Nick Coghlan; python-dev@python.org Subject: Re: [Python-Dev] relative import circular problem So, this is actually an implementation quirk that could be fixed in a (somewhat) straightforward manner: by making from a import b succeed if 'a.b' is in sys.modules, the same way import a.b does. It would require a little bit of discussion to hash out the exact way to do it, but it could be done. Yes, except that from a import b is not only used to import modules. It is pretty much defined to mean b = getattr(a, 'b'). Consider this module: #foo.py # pull helper.helper from its implementation place from .helper import helper now, from foo import helper is expected to get the helper() function, not the helper module, but changing the semantics of the import statement would be surprising. K ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] relative import circular problem
And I should learn to read the entire thread before I start responding. Cheers! K -Original Message- From: Python-Dev [mailto:python-dev- bounces+kristjan=ccpgames@python.org] On Behalf Of Guido van Rossum Sent: 4. apríl 2013 22:47 To: Brett Cannon Cc: PJ Eby; Nick Coghlan; python-dev@python.org Subject: Re: [Python-Dev] relative import circular problem +1 on Brett and PJE just doing this. ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Slides from today's parallel/async Python talk
On Thu, Apr 04, 2013 at 11:53:01PM -0700, Charles-Fran?ois Natali wrote: Hello, async.submit_work(func, args, kwds, callback=None, errback=None) How do you implement arguments passing and return value? e.g. let's say I pass a list as argument: how do you iterate on the list from the worker thread without modifying the backing objects for refcounts (IIUC you use a per-thread heap and don't do any refcounting). Correct, nothing special is done for the arguments (apart from incref'ing them in the main thread before kicking off the parallel thread (then decref'ing them in the main thread once we're sure the parallel thread has finished)). IIUC you incref the argument from the main thread before publishing it to the worker thread: but what about containers like list? How do you make sure the refcounts of the elements don't get deallocated while the worker thread iterates? Ah, so, all of my examples were missing async.run(). They should have looked like this: async.submit_work(foo) async.submit_work(bar) async.run() async.run() is called from the main thread, with the GIL held, and it blocks until all parallel threads (well, parallel contexts, to be exact) have completed. The parallel 'work' doesn't actually start until async.run() is called either. (That's completely untrue at the moment; async.submit_work(foo) will execute foo() in a parallel thread immediately. Fixing that is on the todo list.) With only parallel threads running, no main-thread objects could ever be deallocated*, as no decref'ing is ever done. [*]: unless you went out of your way to delete/deallocate main thread objects via the @async.call_from_main_thread facility. At the moment, that's firmly in the category of Don't Do That. (And, thinking about it a little more, I guess I could augment the ceval loop in such a way that in order for the main thread to run things scheduled via @async.call_from_main_thread, all parallel threads need to be suspended. Or I could just freeze/thaw them (although I don't know if there are POSIX counterparts to those Windows methods). That would definitely impede performance, but it would assure data integrity. Perhaps it should be enabled by default, with the option to disable it for consenting adults.) More generally, how do you deal with non-local objects? Read-only ops against non-local (main-thread) objects from parallel threads are free, which is nice. Things get tricky when you try to mutate main-thread objects from parallel threads. That's where all the context persistence, interlocked data types, object protection etc stuff comes in. Is... that what you mean by how do I deal with non-local objects? I took a guess ;-) Regards, Trent. ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
[Python-Dev] Summary of Python tracker Issues
ACTIVITY SUMMARY (2013-03-29 - 2013-04-05) Python tracker at http://bugs.python.org/ To view or respond to any of the issues listed below, click on the issue. Do NOT respond to this message. Issues counts and deltas: open3905 (+20) closed 25508 (+47) total 29413 (+67) Open issues with patches: 1729 Issues opened (48) == #17425: Update OpenSSL versions in Windows builds http://bugs.python.org/issue17425 reopened by pitrou #17574: pysetup failing with OSError: [Errno 18] Invalid cross-device http://bugs.python.org/issue17574 opened by vaab #17575: HTTPConnection.send http://bugs.python.org/issue17575 opened by dspub...@freemail.hu #17576: PyNumber_Index() is not int-subclass friendly (or operator.ind http://bugs.python.org/issue17576 opened by barry #17577: Add lookahead/peek wrapper to itertools http://bugs.python.org/issue17577 opened by pconnell #17580: ctypes: ARM hardfloat argument corruption calling functions wi http://bugs.python.org/issue17580 opened by bivab #17582: xml.etree.ElementTree does not preserve whitespaces in attribu http://bugs.python.org/issue17582 opened by piro #17583: IDLE HOWTO http://bugs.python.org/issue17583 opened by Amit.Saha #17585: IDLE - regression with exit() and quit() http://bugs.python.org/issue17585 opened by roger.serwy #17588: runpy cannot run Unicode path on Windows http://bugs.python.org/issue17588 opened by Drekin #17589: Make documentation about macros in C API explicit about rvalu http://bugs.python.org/issue17589 opened by larry #17590: mingw: translate gcc internal defines to python platform speci http://bugs.python.org/issue17590 opened by rpetrov #17592: mingw: configure MACHDEP and platform for build http://bugs.python.org/issue17592 opened by rpetrov #17593: mailbox.py tries to link even on filesystem wihch does not sup http://bugs.python.org/issue17593 opened by dominik-stadler #17594: mingw: preset configure defaults http://bugs.python.org/issue17594 opened by rpetrov #17595: mingw: configure largefile support for windows builds http://bugs.python.org/issue17595 opened by rpetrov #17596: mingw: add wincrypt.h in Python/random.c http://bugs.python.org/issue17596 opened by rpetrov #17597: mingw: add $srcdir/PC to CPPFLAGS http://bugs.python.org/issue17597 opened by rpetrov #17598: mingw: init system calls http://bugs.python.org/issue17598 opened by rpetrov #17599: mingw: detect REPARSE_DATA_BUFFER http://bugs.python.org/issue17599 opened by rpetrov #17600: mingw: build-in windows modules (winreg) http://bugs.python.org/issue17600 opened by rpetrov #17601: mingw: determine if pwdmodule should be used http://bugs.python.org/issue17601 opened by rpetrov #17602: mingw: default sys.path calculations for windows platforms http://bugs.python.org/issue17602 opened by rpetrov #17603: AC_LIBOBJ replacement of fileblocks http://bugs.python.org/issue17603 opened by rpetrov #17604: mingw: use main() to start execution http://bugs.python.org/issue17604 opened by rpetrov #17605: mingw-meta: build interpeter core http://bugs.python.org/issue17605 opened by rpetrov #17606: xml.sax.saxutils.XMLGenerator cannot output with the correct e http://bugs.python.org/issue17606 opened by neoecos #17607: missed peephole optimization (unnecessary jump at end of funct http://bugs.python.org/issue17607 opened by Neal.Norwitz #17611: Move unwinding of stack for pseudo exceptions from interpret http://bugs.python.org/issue17611 opened by Mark.Shannon #17612: hooks/mail.py requires [smtp] host to be set, despite a commen http://bugs.python.org/issue17612 opened by eric.smith #17613: IDLE AttributeError: 'NoneType' object has no attribute 'inde http://bugs.python.org/issue17613 opened by rhettinger #17615: String comparison performance regression http://bugs.python.org/issue17615 opened by Neil.Hodgson #17616: wave.Wave_read and wave.Wave_write can be context managers http://bugs.python.org/issue17616 opened by Claudiu.Popa #17618: base85 encoding http://bugs.python.org/issue17618 opened by pitrou #17620: Python interactive console doesn't use sys.stdin for input http://bugs.python.org/issue17620 opened by Drekin #17621: Create a lazy import loader mixin http://bugs.python.org/issue17621 opened by brett.cannon #17626: set's __isub__ doesn't support non-sets. http://bugs.python.org/issue17626 opened by Roy.Wellington #17627: Datetime and time doesn't update timezone in a running Win app http://bugs.python.org/issue17627 opened by cm #17628: str==str: compare the first and last character before calling http://bugs.python.org/issue17628 opened by haypo #17630: Create a pure Python zipfile importer http://bugs.python.org/issue17630 opened by brett.cannon #17631: inspect getsource does not display full text of lambda http://bugs.python.org/issue17631 opened by Alexey.Spiridonov #17633: zipimport's handling of namespace packages is incorrect http://bugs.python.org/issue17633
[Python-Dev] Is file.readlines(sizehint=N) broken on 2.7?
with open('test-xxx', 'w') as f:
f.write('aaa\nbbb\nccc')
with open('test-xxx', 'r') as f:
print(f.readlines(1))
On Python 3.3 I get:
['aaa\n']
...while on Python 2.7:
['aaa\n', 'bbb\n', 'ccc']
Is this a bug or I'm missing something?
--- Giampaolo
https://code.google.com/p/pyftpdlib/
https://code.google.com/p/psutil/
https://code.google.com/p/pysendfile/
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Re: [Python-Dev] Is file.readlines(sizehint=N) broken on 2.7?
The builtin open() was replaced with io.open().
It's difference between file.readlines() and io.IOBase.readlines().
On Sat, Apr 6, 2013 at 2:15 AM, Giampaolo Rodolà g.rod...@gmail.com wrote:
with open('test-xxx', 'w') as f:
f.write('aaa\nbbb\nccc')
with open('test-xxx', 'r') as f:
print(f.readlines(1))
On Python 3.3 I get:
['aaa\n']
...while on Python 2.7:
['aaa\n', 'bbb\n', 'ccc']
Is this a bug or I'm missing something?
--- Giampaolo
https://code.google.com/p/pyftpdlib/
https://code.google.com/p/psutil/
https://code.google.com/p/pysendfile/
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--
INADA Naoki songofaca...@gmail.com
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Re: [Python-Dev] Is file.readlines(sizehint=N) broken on 2.7?
2013/4/5 INADA Naoki songofaca...@gmail.com: The builtin open() was replaced with io.open(). It's difference between file.readlines() and io.IOBase.readlines(). Should that justify this difference in behavior? Apparently on 2.X sizehint does not have any effect as far as I can see. --- Giampaolo https://code.google.com/p/pyftpdlib/ https://code.google.com/p/psutil/ https://code.google.com/p/pysendfile/ ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Is file.readlines(sizehint=N) broken on 2.7?
It's a *hint*, remember? :-) It does work, it's just rounded up to a fairly large number in some implementations. On Fri, Apr 5, 2013 at 11:24 AM, Giampaolo Rodolà g.rod...@gmail.com wrote: 2013/4/5 INADA Naoki songofaca...@gmail.com: The builtin open() was replaced with io.open(). It's difference between file.readlines() and io.IOBase.readlines(). Should that justify this difference in behavior? Apparently on 2.X sizehint does not have any effect as far as I can see. --- Giampaolo https://code.google.com/p/pyftpdlib/ https://code.google.com/p/psutil/ https://code.google.com/p/pysendfile/ ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/guido%40python.org -- --Guido van Rossum (python.org/~guido) ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Is file.readlines(sizehint=N) broken on 2.7?
On Fri, 05 Apr 2013 20:24:43 +0200, =?ISO-8859-1?Q?Giampaolo_Rodol=E0?= g.rod...@gmail.com wrote: 2013/4/5 INADA Naoki songofaca...@gmail.com: The builtin open() was replaced with io.open(). It's difference between file.readlines() and io.IOBase.readlines(). Should that justify this difference in behavior? Yes. The 'file' documentation for readlines says documents that the argument is advisory and may be rounded up to an internal buffer size. io's readlines, on the other hand, says no more lines will be read if the total size of bytes read so far exceeds the hint. So, different semantics. Apparently on 2.X sizehint does not have any effect as far as I can see. Have you played with large enough hints/small enough buffers? --David ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Is file.readlines(sizehint=N) broken on 2.7?
2013/4/5 R. David Murray rdmur...@bitdance.com: On Fri, 05 Apr 2013 20:24:43 +0200, =?ISO-8859-1?Q?Giampaolo_Rodol=E0?= g.rod...@gmail.com wrote: 2013/4/5 INADA Naoki songofaca...@gmail.com: The builtin open() was replaced with io.open(). It's difference between file.readlines() and io.IOBase.readlines(). Should that justify this difference in behavior? Yes. The 'file' documentation for readlines says documents that the argument is advisory and may be rounded up to an internal buffer size. io's readlines, on the other hand, says no more lines will be read if the total size of bytes read so far exceeds the hint. So, different semantics. I see. Apparently on 2.X sizehint does not have any effect as far as I can see. Have you played with large enough hints/small enough buffers? Right, it seems it tends to change around 8196 bytes. Ok then, nevermind. --- Giampaolo https://code.google.com/p/pyftpdlib/ https://code.google.com/p/psutil/ https://code.google.com/p/pysendfile/ ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] [Python-checkins] cpython (merge 3.3 - default): Fix typo
On Fri, Apr 5, 2013 at 1:40 AM, andrew.svetlov python-check...@python.orgwrote: http://hg.python.org/cpython/rev/6cf485ffd325 changeset: 83110:6cf485ffd325 parent: 83106:94fb906e5899 parent: 83109:9610ede72ed2 user:Andrew Svetlov andrew.svet...@gmail.com date:Fri Apr 05 11:40:01 2013 +0300 summary: Fix typo files: Doc/howto/argparse.rst | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/Doc/howto/argparse.rst b/Doc/howto/argparse.rst --- a/Doc/howto/argparse.rst +++ b/Doc/howto/argparse.rst @@ -668,7 +668,7 @@ So far, we have been working with two methods of an :class:`argparse.ArgumentParser` instance. Let's introduce a third one, :meth:`add_mutually_exclusive_group`. It allows for us to specify options that -conflict with each other. Let's also change the rest of the program make the +conflict with each other. Let's also change the rest of the program to make the new functionality makes more sense: snip Andrew, while you're at it you can also fix the rest of the sentence, which makes no sense ;-) Eli ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
