On Sat, Mar 12, 2011 at 9:32 AM, Eli Bendersky eli...@gmail.com wrote:
The devguide's recommendation is to forward-port changes withing a major
release line, i.e. if I need something in all 3.[123], then start with 3.1
and forward-port (by hg merge branch) to 3.2 and then 3.3
Just to clarify
Hello,
I recall several occasions where the peephole optimizer was subtly
buggy -- on one occasion the bug remained undetected for at least a
whole release cycle. (Sorry, I can't recall the details.) In fact, the
bug reported in http://bugs.python.org/issue11244 is another example
of how
FWIW, I'm -1 on backing out Antoine's patch. In addition to fixing
the minor optimization regression, it makes the peepholer
significantly more consistent in what it can and can't fold. One of
the first times that I delved into the peepholer code was to try to
understand why expressions like: 2
Hello,
Am I missing something? Does SETUP_LOOP serve any other purpose?
Not to my knowledge.
Similarly, it looks like BREAK_LOOP and CONTINUE_LOOP are just jumps
that respect try/finally blocks (i.e. jumping out of try executes
finally). Is there more semantics to them than this?
There
On Sat, Mar 12, 2011 at 5:07 AM, Mark Dickinson dicki...@gmail.com wrote:
I can also see the case for ripping out the peepholer entirely. But
reverting Antoine's patch seems like a step backwards.
+1 to what Mark says here.
If the day comes when the peepholer can be ripped out in favour of
Am 12.03.11 04:03, schrieb Nadeem Vawda:
Hmm... it seems that the given instructions don't actually work. hg
revert -a fails,
saying that a specific revision needs to be provided. The command should be
hg revert -ar default.
Isn't that command correct only if you are merging into default?
ISTM
On Mar 11, 2011, at 7:12 PM, Paul Moore wrote:
On 11 March 2011 23:24, Guido van Rossum gu...@python.org wrote:
I'm interested in the task and I guess I'll follow-up with Doug Hellman. I
don't follow -ideas close enough to summarize it, but I'd contribute to a
-dev blog.
Awesome! (And we
I posted my rough notes and additional write-ups for Wednesday's VM
summit and Thursday's language summit:
http://www.boredomandlaziness.org/2011/03/python-vm-summit-rough-notes.html
http://www.boredomandlaziness.org/2011/03/python-vm-summit-somewhat-coherent.html
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
...
I have always felt uncomfortable with *any* kind of optimization --
whether AST-based or bytecode-based. I feel the cost in code
complexity is pretty high and in most cases the optimization is not
worth the effort. Also I don't see the point
There are also with blocks :-) (which use separate opcodes, although
they are similar in principle to try/finally blocks)
IIUC they use separate opcode, but the same block type (SETUP_FINALLY).
There may be complications with nested try/finally blocks. You either
need to generate separate
For those of you not at the Language Summit at PyCON the day before yesterday,
there was talk of identifying non-portable behaviour, such as relying on
CPython's reference counting garbage collector to close files for you as
soon as they become unreachable. And then warning about them.
We have a
On Sat, Mar 12, 2011 at 8:33 AM, Laura Creighton l...@openend.se wrote:
For those of you not at the Language Summit at PyCON the day before yesterday,
there was talk of identifying non-portable behaviour, such as relying on
CPython's reference counting garbage collector to close files for you
Could someone with the right access add a Python 3.4 version to the
tracker? I have a deprecation warning that I need to make an error in 3.4.
I'd also like to make it a release blocker in 3.4 so I don't forget
about it. If I do that, will it screw up any release workflow?
Thanks.
Hi,
I have been offered commit rights for Python after making a few patches
on subprocess and the os module.
Antoine suggested that I should introduce myself on the python-dev list
so here we go:
I am a student from South Africa and decided to do some work on Python
in my spare time. I think I
Am 12.03.11 09:26, schrieb Eric Smith:
Could someone with the right access add a Python 3.4 version to the
tracker?
Done.
I'd also like to make it a release blocker in 3.4 so I don't forget
about it. If I do that, will it screw up any release workflow?
I don't think so. As release managers
I have a deprecation warning that I need to make an error in 3.4.
A neat trick to remember to do those changes is using a test that fails
if something does not raise a DeprecationWarning if sys.version_info[:2]
== (3, 3), or an error if sys.version_info[:3] == (3, 4). You write
those tests once
Hi,
i've a storage engine that stores a lot of files (e.g. 10.000) in
one path. Running the code under cProfile, I found that with a total
CPU-time of 1,118 seconds, 121 seconds are spent in 27.013 calls to
open(). The number of calls is not the problem; however I find it
*very* discomforting
On Sat, 12 Mar 2011 16:55:30 +0100
Éric Araujo mer...@netwok.org wrote:
I have a deprecation warning that I need to make an error in 3.4.
A neat trick to remember to do those changes is using a test that fails
if something does not raise a DeprecationWarning if sys.version_info[:2]
== (3,
Hi
What OS and what file system you are using? Many file systems (e,g.
ext2/3fs) handle large directories very poorly.
A quick way to check if this has anything to do with Python is writing
a small C program that opens these files and time it.
Eugene
On Sat, Mar 12, 2011 at 10:13 AM, Lukas Lueg
There are separate social, strategic, and tactical questions.
The social question: if the person who designed, implemented, and maintained
the optimizer recommends against a patch and another committer just checks it
in anyway, do we care? I've taken responsibility for this code and have
Hi,
I posted my rough notes and additional write-ups for Wednesday's VM
summit and Thursday's language summit:
Thanks for doing that!
About this bit from the VM meeting notes:
- original Python-on-Parrot ran into problems due to semantic
mismatches between Perl 6 and Python - reached the
On 03/12/2011 10:55 AM, Éric Araujo wrote:
I have a deprecation warning that I need to make an error in 3.4.
A neat trick to remember to do those changes is using a test that fails
if something does not raise a DeprecationWarning if sys.version_info[:2]
== (3, 3), or an error if
Am 12.03.2011 16:13, schrieb Lukas Lueg:
i've a storage engine that stores a lot of files (e.g. 10.000) in
one path. Running the code under cProfile, I found that with a total
CPU-time of 1,118 seconds, 121 seconds are spent in 27.013 calls to
open(). The number of calls is not the problem;
On Sat, Mar 12, 2011 at 11:08 AM, Éric Araujo mer...@netwok.org wrote:
Hi,
I posted my rough notes and additional write-ups for Wednesday's VM
summit and Thursday's language summit:
Thanks for doing that!
About this bit from the VM meeting notes:
- original Python-on-Parrot ran into
I would like to withdraw my suggestion for the recursive constant folding patch
to be reverted. I value social harmony much more than a decision about whether
a particular patch is a good idea. I apologize to anyone who is upset over the
discussion.
Raymond
http://www.boredomandlaziness.org/2011/03/python-vm-summit-rough-notes.html
http://www.boredomandlaziness.org/2011/03/python-vm-summit-somewhat-coherent.html
Wrt. the remark that other implementations should be referenced more
prominently: I added them to
http://www.python.org/download/
On Sat, Mar 12, 2011 at 8:59 AM, Nick Coghlan ncogh...@gmail.com wrote:
On Sat, Mar 12, 2011 at 8:33 AM, Laura Creighton l...@openend.se wrote:
For those of you not at the Language Summit at PyCON the day before
yesterday,
there was talk of identifying non-portable behaviour, such as relying
On 03/12/2011 11:17 AM, Nick Coghlan wrote:
About this bit from the VM meeting notes:
- original Python-on-Parrot ran into problems due to semantic
mismatches between Perl 6 and Python - reached the limits of the
degree of difference the Perl 6 toolchain was willing to tolerate)
Would you
Welcome Ross! Glad you like the new dev guide. (Brett and the
community should be proud of their recent work on that.) Remember,
there are no stupid questions. And while occasionally it may appear as
if someone tries to bite your head off, our bite is not as bad as our
bark.
--Guido
On Sat, Mar
On 3/12/2011 9:41 AM, Ross Lagerwall wrote:
Hi,
I have been offered commit rights for Python after making a few patches
on subprocess and the os module.
Antoine suggested that I should introduce myself on the python-dev list
so here we go:
I am a student from South Africa and decided to do
On Sat, Mar 12, 2011 at 1:14 PM, Martin v. Löwis mar...@v.loewis.de wrote:
http://www.boredomandlaziness.org/2011/03/python-vm-summit-rough-notes.html
http://www.boredomandlaziness.org/2011/03/python-vm-summit-somewhat-coherent.html
Wrt. the remark that other implementations should be
At 08:25 AM 3/12/2011 -0500, Eugene Toder wrote:
Right, I'm not suggesting to remove all blocks, only SETUP_LOOP
blocks. Do you see the problem in that case?
I think you guys are forgetting about FOR_ITER, listcomps, and the like.
That is, IIRC, the reason loops use the block stack is because
On Sat, Mar 12, 2011 at 1:41 PM, Guido van Rossum gu...@python.org wrote:
Yeah, indeed, on everything you said. The code dispatching based on
internal slots is horribly ad-hoc and likely wrong in subtle ways. Has
any of this improved in Python 3?
Not that I know of - I was definitely able to
On 3/12/2011 8:59 AM, Nick Coghlan wrote:
On Sat, Mar 12, 2011 at 8:33 AM, Laura Creightonl...@openend.se wrote:
For those of you not at the Language Summit at PyCON the day before yesterday,
there was talk of identifying non-portable behaviour, such as relying on
CPython's reference counting
On Sat, Mar 12, 2011 at 14:52, Terry Reedy tjre...@udel.edu wrote:
On 3/12/2011 8:59 AM, Nick Coghlan wrote:
(obviously, history now means that changing our behaviour would
require a deprecation period)
I disagree. Behavior that contradicts intent and doc is a bug and should be
fixed.
I was just reminded that in Python 3, list.sort() and sorted() no
longer support the cmp (comparator) function argument. The reason is
that the key function argument is always better. But now I have a
nagging doubt about this:
I recently advised a Googler who was sorting a large dataset and
On 3/12/2011 3:04 PM, Thomas Wouters wrote:
It should be fixed, yes, but breaking existing code is going to piss off
a lot of people (like me) who already have enough worries when upgrading
Python. It is apparent that there *is* code out there that relies on
this behaviour, we shouldn't break
Hello,
Finally: There appears to be some disagreement on who said what, in
particular Raymond claims that he told Antoine not to commit whereas
Antoine claims he did not hear this feedback. I'm guessing it happened
in IRC (#python-dev), which is intentionally not logged anywhere.
Raymond
On 3/12/2011 8:33 AM, Laura Creighton wrote:
The thread with the whole gory details begins here:
http://codespeak.net/pipermail/pypy-dev/2011q1/006958.html
The second, multiplication issue does appears to be the same issue.
Augmenting my previous test:
class C(object):
def
On Sat, 12 Mar 2011 13:08:26 -0500
Raymond Hettinger raymond.hettin...@gmail.com wrote:
I would like to withdraw my suggestion for the recursive constant folding
patch to be reverted. I value social harmony much more than a decision about
whether a particular patch is a good idea. I
They should be able to use a slotted cmp_to_key style class:
http://docs.python.org/howto/sorting.html
That will allocate 1 Python object with no dict per key, but that
might not be good enough.
Reid
On Sat, Mar 12, 2011 at 3:44 PM, Guido van Rossum gu...@python.org wrote:
I was just reminded
On Sat, Mar 12, 2011 at 9:44 PM, Guido van Rossum gu...@python.org wrote:
I was just reminded that in Python 3, list.sort() and sorted() no
longer support the cmp (comparator) function argument. The reason is
that the key function argument is always better. But now I have a
nagging doubt about
On Sat, Mar 12, 2011 at 4:50 PM, Reid Kleckner reid.kleck...@gmail.com wrote:
They should be able to use a slotted cmp_to_key style class:
http://docs.python.org/howto/sorting.html
That will allocate 1 Python object with no dict per key, but that
might not be good enough.
Tuples are already
Guido van Rossum wrote:
IIUC Thomas found that this breaks some current use of staticmethod.
I*I*UC, it wasn't making it callable that was the problem,
it was changing the behaviour so that the staticmethod
wrapper returns itself instead of the underlying object
when accessed as a descriptor.
On 3/12/2011 3:44 PM, Guido van Rossum wrote:
I was just reminded that in Python 3, list.sort() and sorted() no
longer support the cmp (comparator) function argument. The reason is
that the key function argument is always better. But now I have a
nagging doubt about this:
I recently advised a
On Sat, Mar 12, 2011 at 4:58 PM, Nick Coghlan ncogh...@gmail.com wrote:
On Sat, Mar 12, 2011 at 4:50 PM, Reid Kleckner reid.kleck...@gmail.com
wrote:
They should be able to use a slotted cmp_to_key style class:
http://docs.python.org/howto/sorting.html
That will allocate 1 Python object
On 3/12/2011 10:42 AM, Allison Randal wrote:
I might convert it directly into a QA blog post.
I'd like to see that, or a summary, posted here. As a Perl-to-Python
convertee, I'm curious about the problematic semantic differences.
___
Python-Dev
On Sat, Mar 12, 2011 at 1:29 PM, Martin v. Löwis mar...@v.loewis.de wrote:
Isn't that command correct only if you are merging into default?
ISTM that it should be hg revert -ar targetbranch.
In general, yes. However, the existing text refers specifically to the
case of merging 3.2
into default,
Can sort have an option (and/or try to figure it itself) to calculate
key for every comparison instead of caching them? This will have the
same memory requirements as with cmp, but doesn't require rewriting
code if you decide to trade speed for memory. Will this be much slower
than with cmp?
If
On Sun, 13 Mar 2011 00:24:07 +0200
Nadeem Vawda nadeem.va...@gmail.com wrote:
On Sat, Mar 12, 2011 at 1:29 PM, Martin v. Löwis mar...@v.loewis.de wrote:
Isn't that command correct only if you are merging into default?
ISTM that it should be hg revert -ar targetbranch.
In general, yes.
Am 12.03.11 16:58, schrieb Nick Coghlan:
On Sat, Mar 12, 2011 at 4:50 PM, Reid Klecknerreid.kleck...@gmail.com wrote:
They should be able to use a slotted cmp_to_key style class:
http://docs.python.org/howto/sorting.html
That will allocate 1 Python object with no dict per key, but that
might
2011/3/12 Maciej Fijalkowski fij...@gmail.com:
On Sat, Mar 12, 2011 at 1:14 PM, Martin v. Löwis mar...@v.loewis.de wrote:
http://www.boredomandlaziness.org/2011/03/python-vm-summit-rough-notes.html
http://www.boredomandlaziness.org/2011/03/python-vm-summit-somewhat-coherent.html
Wrt. the
Guido van Rossum wrote:
I was just reminded that in Python 3, list.sort() and sorted() no
longer support the cmp (comparator) function argument. The reason is
that the key function argument is always better. But now I have a
nagging doubt about this:
I recently advised a Googler who was
hg revert -ar default
You can’t combine the -r option with other options. (Yes, it’s a known
bug.)
On an unrelated note, you can use “-r .” to tell Mercurial to find the
branch name from the working directory instead of having to remember and
retype it.
Regards
On Sat, Mar 12, 2011 at 5:41 PM, Martin v. Löwis mar...@v.loewis.de wrote:
Why not? IIUC, the current key function creates three objects: the tuple,
the short string, and the int. With the class
Yeah, I misread the example. Using cmp_to_key would indeed save quite
a lot of memory in this case.
But in Python 3 this solution is no longer available. How bad is that?
I'm not sure. But I'd like to at least get the issue out in the open.
Rather than reintroducing cmp=, I'd add a cached=True parameter.
If this is set to False, the key results wouldn't be put into a
list, but recreated every
On Sun, Mar 13, 2011 at 12:43 AM, Éric Araujo mer...@netwok.org wrote:
hg revert -ar default
You can’t combine the -r option with other options. (Yes, it’s a known bug.)
It seems to work for me (Mercurial 1.6.3 on Ubuntu). But I suppose it
wouldn't hurt
to split the options up.
Regards,
On 3/12/2011 1:55 PM, Fredrik Johansson wrote:
Consider sorting a list of pairs representing fractions. This can be
done easily in Python 2.x with the comparison function lambda
(p,q),(r,s): cmp(p*s, q*r). In Python 2.6, this is about 40 times
faster than using fractions.Fraction as a key
On Sat, 12 Mar 2011 23:43:52 +0100
Éric Araujo mer...@netwok.org wrote:
hg revert -ar default
You can’t combine the -r option with other options. (Yes, it’s a known
bug.)
Are you sure? It just worked here:
$ hg rev -ar default
reverting README
(perhaps you're thinking of -R instead?)
On Sat, Mar 12, 2011 at 17:08, Greg Ewing greg.ew...@canterbury.ac.nzwrote:
Guido van Rossum wrote:
IIUC Thomas found that this breaks some current use of staticmethod.
I*I*UC, it wasn't making it callable that was the problem,
it was changing the behaviour so that the staticmethod
On 3/12/2011 3:43 AM, Nick Coghlan wrote:
I posted my rough notes and additional write-ups for Wednesday's VM
summit and Thursday's language summit:
http://www.boredomandlaziness.org/2011/03/python-vm-summit-rough-notes.html
2.7 to 3.2
- treat PyPy Python 3 dialect like a major Python
You can’t combine the -r option with other options. (Yes, it’s a known
bug.)
Are you sure? It just worked here: [...]
(perhaps you're thinking of -R instead?)
Exactly.
On an unrelated note, you can use “-r .” to tell Mercurial to find the
branch name from the working directory instead of
In article 1299940862.1632.7.camel@hobo,
Ross Lagerwall rosslagerw...@gmail.com wrote:
I have been offered commit rights for Python after making a few patches
on subprocess and the os module.
Antoine suggested that I should introduce myself on the python-dev list
so here we go:
I am a
On Sat, Mar 12, 2011 at 6:04 PM, Glenn Linderman v+pyt...@g.nevcal.com wrote:
On 3/12/2011 3:43 AM, Nick Coghlan wrote:
I posted my rough notes and additional write-ups for Wednesday's VM
summit and Thursday's language summit:
Nick Coghlan wrote:
I'm actually tempted to call the current CPython semantics flatout
*wrong*.
So am I. It seems to result from the hisorical mess
of distinguishing between numeric and sequence operations
at the C level but not the Python level. I think CPython
should be moving in the
Am 12.03.11 18:00, schrieb Glenn Linderman:
On 3/12/2011 1:55 PM, Fredrik Johansson wrote:
Consider sorting a list of pairs representing fractions. This can be
done easily in Python 2.x with the comparison function lambda
(p,q),(r,s): cmp(p*s, q*r). In Python 2.6, this is about 40 times
On 03/12/2011 05:13 PM, Glenn Linderman wrote:
On 3/12/2011 10:42 AM, Allison Randal wrote:
I might convert it directly into a QA blog post.
I'd like to see that, or a summary, posted here. As a Perl-to-Python
convertee, I'm curious about the problematic semantic differences.
The short
On Sun, Mar 13, 2011 at 12:41 AM, Martin v. Löwis mar...@v.loewis.de wrote:
Am 12.03.11 18:00, schrieb Glenn Linderman:
On 3/12/2011 1:55 PM, Fredrik Johansson wrote:
Consider sorting a list of pairs representing fractions. This can be
done easily in Python 2.x with the comparison function
On Sat, 2011-03-12 at 12:49 +1300, Greg Ewing wrote:
Thomas Wouters wrote:
2. Make CFunctions turn into methods in CPython (after a period of
warning about the impending change, obviously.) The actual *usecase* for
this is hard to envision
While not necessary for the case being
Raymond The social question: if the person who designed, implemented,
Raymond and maintained the optimizer recommends against a patch and
Raymond another committer just checks it in anyway, do we care?
Guido - you're dangerously close here to putting your ego ahead of
Guido
Maybe, but we have historically tended to give some extra weight to the
primary author of at least modules and packages. If someone wanted to make
a significant change to xml.etree, I think we would give reasonably large
weight to Fredrik Lundh's opinion on the change. If the peephole optimizer
On 3/12/2011 5:09 PM, Reid Kleckner wrote:
On Sat, Mar 12, 2011 at 4:58 PM, Nick Coghlanncogh...@gmail.com wrote:
On Sat, Mar 12, 2011 at 4:50 PM, Reid Klecknerreid.kleck...@gmail.com wrote:
They should be able to use a slotted cmp_to_key style class:
Greg Ewing greg.ew...@canterbury.ac.nz wrote:
So am I. It seems to result from the hisorical mess
of distinguishing between numeric and sequence operations
at the C level but not the Python level. I think CPython
should be moving in the direction of eliminating that
distinction, not expecting
Thomas Wouters wrote:
I would much rather loudly warn people to fix their code, instead of forcing
other implementations (and, more importantly to me personally, future
CPython changes :) to deal with the distinction forever. But if we declare a
wrapper to be the right way to deal with this,
Fredrik Johansson wrote:
Consider sorting a list of pairs representing fractions. This can be
done easily in Python 2.x with the comparison function lambda
(p,q),(r,s): cmp(p*s, q*r). In Python 2.6, this is about 40 times
faster than using fractions.Fraction as a key function.
[steve@sylar
On 3/12/2011 2:09 PM, Terry Reedy wrote:
I believe that if the integer field were padded with leading blanks as
needed so that all are the same length, then no key would be needed.
Did you mean that if the integer field were converted to string and
padded with leading blanks...?
Otherwise
I believe the tracker sent an error message to python-dev as a
result of a failed hook execution. If someone with the
power would release that message so we can see what the error
was, I'd appreciate it :)
--David
___
Python-Dev mailing list
On 3/12/2011 8:28 PM, Steven D'Aprano wrote:
Fredrik Johansson wrote:
Consider sorting a list of pairs representing fractions. This can be
done easily in Python 2.x with the comparison function lambda
(p,q),(r,s): cmp(p*s, q*r). In Python 2.6, this is about 40 times
faster than using
On 3/12/2011 8:23 PM, Neil Schemenauer wrote:
Greg Ewinggreg.ew...@canterbury.ac.nz wrote:
So am I. It seems to result from the hisorical mess
of distinguishing between numeric and sequence operations
at the C level but not the Python level. I think CPython
should be moving in the direction of
[steve@sylar ~]$ python2.7 -m timeit -s L = [(1,2), (3,4), (0,5),
(9,100), (3,7), (2,8)] sorted(L, lambda (p,q),(r,s): cmp(p*s, q*r))
1 loops, best of 3: 25.1 usec per loop
[steve@sylar ~]$ python2.7 -m timeit -s L = [(1,2), (3,4), (0,5),
(9,100), (3,7), (2,8)] -s from fractions import
On Mar 12, 2011, at 3:44 PM, Guido van Rossum wrote:
I was just reminded that in Python 3, list.sort() and sorted() no
longer support the cmp (comparator) function argument. The reason is
that the key function argument is always better. But now I have a
nagging doubt about this:
I
On 3/12/2011 8:47 PM, Glenn Linderman wrote:
On 3/12/2011 2:09 PM, Terry Reedy wrote:
I believe that if the integer field were padded with leading blanks as
needed so that all are the same length, then no key would be needed.
Did you mean that if the integer field were converted to string and
Martin I don't think any of the regular core committers got any such
Martin explicit veto powers on any code...
Veto powers is your term, not mine. I suggested that Raymond's opinion
should be accorded extra weight. This isn't the UN Security Council.
Skip
Am 12.03.11 22:36, schrieb s...@pobox.com:
Martin I don't think any of the regular core committers got any such
Martin explicit veto powers on any code...
Veto powers is your term, not mine. I suggested that Raymond's opinion
should be accorded extra weight. This isn't the UN
On 3/12/2011 7:21 PM, Terry Reedy wrote:
(Ok, I assumed that the 'word' field does not include any of
!#$%'()*+. If that is not true, replace comma with space or even a
control char such as '\a' which even precedes \t and \n.)
OK, I agree the above was your worst assumption, although you need
Martin == Martin v Löwis mar...@v.loewis.de writes:
Martin Am 12.03.11 22:36, schrieb s...@pobox.com:
Martin I don't think any of the regular core committers got any such
Martin explicit veto powers on any code...
Veto powers is your term, not mine. I suggested that
On 3/12/2011 10:52 PM, Glenn Linderman wrote:
On 3/12/2011 7:21 PM, Terry Reedy wrote:
The safest such character is \0,\
Works fine in Python.
unless you are coding in C,
Then \01 is next best.
I wouldn't have called you on this, except that it really is important
not to give people
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