Mailman 3 March 2012 - Python-Dev

Playing with a new theme for the docs
by Georg Brandl March 28, 2012

March 28, 2012

Hi all, recently I've grown a bit tired of seeing our default Sphinx theme, especially as so many other projects use it. I decided to play around with something "clean" this time, and this is the result: http://www.python.org/~gbrandl/build/html/ The corresponding sandbox repo is at http://hg.python.org/sandbox/doc-theme/#doc-theme Let me know what you think, or play around and send some improvements. (The collapsible sidebar is not adapted to it yet, but will definitely be integrated before I consider applying a new theme to the real docs.) Thanks, Georg

33 84

Re: [Python-Dev] [Python-checkins] peps: Approve PEP 411.
by Victor Stinner March 27, 2012

March 27, 2012

2012/3/27 guido.van.rossum <python-checkins(a)python.org>: > http://hg.python.org/peps/rev/b9f43fe69691 > changeset: 4152:b9f43fe69691 > user: Guido van Rossum <guido(a)google.com> > date: Mon Mar 26 20:35:14 2012 -0700 > summary: > Approve PEP 411. > (...) > -Status: Draft > +Status: Approved The pep0 module doesn't accept the "Approved" status. I suppose that you mean "Accepted" and so changed the status. If not, please revert my change and fix the pep0 module. Victor

1 0

how to uninstall python after 'make build'
by Linker March 27, 2012

March 27, 2012

RT thx. linker

1 0

PendingDeprecationWarning
by Terry Reedy March 27, 2012

March 27, 2012

My impression is that the original reason for PendingDeprecationWarning versus DeprecationWarning was to be off by default until the last release before removal. But having DeprecationWarnings on by default was found to be too obnoxious and it too is off by default. So do we still need PendingDeprecationWarnings? My impression is that it is mostly not used, as it is a nuisance to remember to change from one to the other. The deprecation message can always indicate the planned removal time. I searched the Developer's Guide for both deprecation and DeprecationWarning and found nothing. -- Terry Jan Reedy

4 3

Playing with a new theme for the docs, iteration 2
by Georg Brandl March 27, 2012

March 27, 2012

Here's another try, mainly with default browser font size, more contrast and collapsible sidebar again: http://www.python.org/~gbrandl/build/html2/ I've also added a little questionable gimmick to the sidebar (when you collapse it and expand it again, the content is shown at your current scroll location). Have fun! Georg

27 59

PEP 411 - request for pronouncement
by Eli Bendersky March 26, 2012

March 26, 2012

Hello, PEP 411 -- Provisional packages in the Python standard library Has been updated with all accumulated feedback from list discussions. Here it is: http://www.python.org/dev/peps/pep-0411/ (the text is also pasted in the bottom of this email). The PEP received mostly positive feedback. The only undecided point is where to specify that the package is provisional. Currently the PEP mandates to specify it in the documentation and in the docstring. Other suggestions were to put it in the code, either as a __provisional__ attribute on the module, or collect all such modules in a single sys.provisional list. According to http://blog.python.org/2012/03/2012-language-summit-report.html, the PEP was discussed in the language summit and overall viewed positively, although no final decision has been reached. ISTM a decision needs to be taken, which is why I request pronouncement, with a recommendation on the requirement the PEP should make of provisional modules (process details). Eli -------------------------------- PEP: 411 Title: Provisional packages in the Python standard library Version: $Revision$ Last-Modified: $Date$ Author: Nick Coghlan <ncoghlan(a)gmail.com>, Eli Bendersky <eliben(a)gmail.com> Status: Draft Type: Informational Content-Type: text/x-rst Created: 2012-02-10 Python-Version: 3.3 Post-History: 2012-02-10 Abstract ======== The process of including a new package into the Python standard library is hindered by the API lock-in and promise of backward compatibility implied by a package being formally part of Python. This PEP describes a methodology for marking a standard library package "provisional" for the period of a single minor release. A provisional package may have its API modified prior to "graduating" into a "stable" state. On one hand, this state provides the package with the benefits of being formally part of the Python distribution. On the other hand, the core development team explicitly states that no promises are made with regards to the the stability of the package's API, which may change for the next release. While it is considered an unlikely outcome, such packages may even be removed from the standard library without a deprecation period if the concerns regarding their API or maintenance prove well-founded. Proposal - a documented provisional state ========================================= Whenever the Python core development team decides that a new package should be included into the standard library, but isn't entirely sure about whether the package's API is optimal, the package can be included and marked as "provisional". In the next minor release, the package may either be "graduated" into a normal "stable" state in the standard library, remain in provisional state, or be rejected and removed entirely from the Python source tree. If the package ends up graduating into the stable state after being provisional, its API may be changed according to accumulated feedback. The core development team explicitly makes no guarantees about API stability and backward compatibility of provisional packages. Marking a package provisional ----------------------------- A package will be marked provisional by a notice in its documentation page and its docstring. The following paragraph will be added as a note at the top of the documentation page: The <X> package has been included in the standard library on a provisional basis. Backwards incompatible changes (up to and including removal of the package) may occur if deemed necessary by the core developers. The phrase "provisional basis" will then be a link to the glossary term "provisional package", defined as: A provisional package is one which has been deliberately excluded from the standard library's normal backwards compatibility guarantees. While major changes to such packages are not expected, as long as they are marked provisional, backwards incompatible changes (up to and including removal of the package) may occur if deemed necessary by core developers. Such changes will not be made gratuitously - they will occur only if serious flaws are uncovered that were missed prior to the inclusion of the package. This process allows the standard library to continue to evolve over time, without locking in problematic design errors for extended periods of time. See PEP 411 for more details. The following will be added to the start of the packages's docstring: The API of this package is currently provisional. Refer to the documentation for details. Moving a package from the provisional to the stable state simply implies removing these notes from its documentation page and docstring. Which packages should go through the provisional state ------------------------------------------------------ We expect most packages proposed for addition into the Python standard library to go through a minor release in the provisional state. There may, however, be some exceptions, such as packages that use a pre-defined API (for example ``lzma``, which generally follows the API of the existing ``bz2`` package), or packages with an API that has wide acceptance in the Python development community. In any case, packages that are proposed to be added to the standard library, whether via the provisional state or directly, must fulfill the acceptance conditions set by PEP 2. Criteria for "graduation" ------------------------- In principle, most provisional packages should eventually graduate to the stable standard library. Some reasons for not graduating are: * The package may prove to be unstable or fragile, without sufficient developer support to maintain it. * A much better alternative package may be found during the preview release. Essentially, the decision will be made by the core developers on a per-case basis. The point to emphasize here is that a package's inclusion in the standard library as "provisional" in some release does not guarantee it will continue being part of Python in the next release. Rationale ========= Benefits for the core development team -------------------------------------- Currently, the core developers are really reluctant to add new interfaces to the standard library. This is because as soon as they're published in a release, API design mistakes get locked in due to backward compatibility concerns. By gating all major API additions through some kind of a provisional mechanism for a full release, we get one full release cycle of community feedback before we lock in the APIs with our standard backward compatibility guarantee. We can also start integrating provisional packages with the rest of the standard library early, so long as we make it clear to packagers that the provisional packages should not be considered optional. The only difference between provisional APIs and the rest of the standard library is that provisional APIs are explicitly exempted from the usual backward compatibility guarantees. Benefits for end users ---------------------- For future end users, the broadest benefit lies in a better "out-of-the-box" experience - rather than being told "oh, the standard library tools for task X are horrible, download this 3rd party library instead", those superior tools are more likely to be just be an import away. For environments where developers are required to conduct due diligence on their upstream dependencies (severely harming the cost-effectiveness of, or even ruling out entirely, much of the material on PyPI), the key benefit lies in ensuring that all packages in the provisional state are clearly under python-dev's aegis from at least the following perspectives: * Licensing: Redistributed by the PSF under a Contributor Licensing Agreement. * Documentation: The documentation of the package is published and organized via the standard Python documentation tools (i.e. ReST source, output generated with Sphinx and published on http://docs.python.org). * Testing: The package test suites are run on the python.org buildbot fleet and results published via http://www.python.org/dev/buildbot. * Issue management: Bugs and feature requests are handled on http://bugs.python.org * Source control: The master repository for the software is published on http://hg.python.org. Candidates for provisional inclusion into the standard library ============================================================== For Python 3.3, there are a number of clear current candidates: * ``regex`` (http://pypi.python.org/pypi/regex) - approved by Guido [#]_. * ``daemon`` (PEP 3143) * ``ipaddr`` (PEP 3144) Other possible future use cases include: * Improved HTTP modules (e.g. ``requests``) * HTML 5 parsing support (e.g. ``html5lib``) * Improved URL/URI/IRI parsing * A standard image API (PEP 368) * Improved encapsulation of import state (PEP 406) * Standard event loop API (PEP 3153) * A binary version of WSGI for Python 3 (e.g. PEP 444) * Generic function support (e.g. ``simplegeneric``) Rejected alternatives and variations ==================================== See PEP 408. References ========== .. [#] http://mail.python.org/pipermail/python-dev/2012-January/115962.html Copyright ========= This document has been placed in the public domain. .. Local Variables: mode: indented-text indent-tabs-mode: nil sentence-end-double-space: t fill-column: 70 coding: utf-8 End:

3 8

Drop the new time.wallclock() function?
by Victor Stinner March 26, 2012

March 26, 2012

Hi, I added two functions to the time module in Python 3.3: wallclock() and monotonic(). I'm unable to explain the difference between these two functions, even if I wrote them :-) wallclock() is suppose to be more accurate than time() but has an unspecified starting point. monotonic() is similar except that it is monotonic: it cannot go backward. monotonic() may not be available or fail whereas wallclock() is available/work, but I think that the two functions are redundant. I prefer to keep only monotonic() because it is not affected by system clock update and should help to fix issues on NTP update in functions implementing a timeout. What do you think? -- monotonic() has 3 implementations: * Windows: QueryPerformanceCounter() with QueryPerformanceFrequency() * Mac OS X: mach_absolute_time() with mach_timebase_info() * UNIX: clock_gettime(CLOCK_MONOTONIC_RAW) or clock_gettime(CLOCK_MONOTONIC) wallclock() has 3 implementations: * Windows: QueryPerformanceCounter() with QueryPerformanceFrequency(), with a fallback to GetSystemTimeAsFileTime() if QueryPerformanceFrequency() failed * UNIX: clock_gettime(CLOCK_MONOTONIC_RAW), clock_gettime(CLOCK_MONOTONIC) or clock_gettime(CLOCK_REALTIME), with a fallback to gettimeofday() if clock_gettime(*) failed * Otherwise: gettimeofday() (wallclock should also use mach_absolute_time() on Mac OS X) Victor

21 66

Re: [Python-Dev] [Python-checkins] cpython: Issue #7652: Integrate the decimal floating point libmpdec library to speed
by Victor Stinner March 26, 2012

March 26, 2012

>> http://hg.python.org/cpython/rev/7355550d5357 >> changeset: 75850:7355550d5357 >> user: Stefan Krah <skrah(a)bytereef.org> >> date: Wed Mar 21 18:25:23 2012 +0100 >> summary: >> Issue #7652: Integrate the decimal floating point libmpdec library to speed >> up the decimal module. Performance gains of the new C implementation are >> between 12x and 80x, depending on the application. Congrats Stefan! And thanks for the huge chunk of code. Victor

6 14

Re: [Python-Dev] cpython: Fix time.steady(strict=True): don't use CLOCK_REALTIME
by Antoine Pitrou March 26, 2012

March 26, 2012

On Mon, 26 Mar 2012 22:53:37 +0200 victor.stinner <python-checkins(a)python.org> wrote: > http://hg.python.org/cpython/rev/566527ace50b > changeset: 75960:566527ace50b > user: Victor Stinner <victor.stinner(a)gmail.com> > date: Mon Mar 26 22:53:14 2012 +0200 > summary: > Fix time.steady(strict=True): don't use CLOCK_REALTIME Victor, could we have a PEP on all this? I think everyone has lost track of what you are trying to do with these new methods. cheers Antoine.

1 0

Re: [Python-Dev] Python install layout and the PATH on win32 (Rationale part 1: Regularizing the layout)
by PJ Eby March 26, 2012

March 26, 2012

On Mar 23, 2012 3:53 PM, "Carl Meyer" <carl(a)oddbird.net> wrote: > > Hi PJ, > > On 03/23/2012 12:35 PM, PJ Eby wrote: > > AFAICT, virtualenvs are overkill for most development anyway. If you're > > not using distutils except to install dependencies, then configure > > distutils to install scripts and libraries to the same directory, and > > then do all your development in that directory. Presto! You now have a > > cross-platform "virtualenv". Want the scripts on your path? Add that > > directory to your path... or if on Windows, don't bother, since the > > current directory is usually on the path. (In fact, if you're only > > using easy_install to install your dependencies, you don't even need to > > edit the distutils configuration, just use "-md targetdir".) > > Creating and using a virtualenv is, in practice, _easier_ than any of > those alternatives, Really? As I said, I've never seen the need to try, since just installing stuff to a directory on PYTHONPATH seems quite easy enough for me. > that the "isolation from system site-packages" feature is quite popular > (the outpouring of gratitude when virtualenv went isolated-by-default a > few months ago was astonishing), and AFAIK none of your alternative > proposals support that at all. What is this isolation for, exactly? If you don't want site-packages on your path, why not use python -S? (Sure, nobody knows about these things, but surely that's a documentation problem, not a tooling problem.) Don't get me wrong, I don't have any deep objection to virtualenvs, I've just never seen the *point* (outside of the scenarios I mentioned), and thus don't see what great advantage will be had by rearranging layouts to make them shareable across platforms, when "throw stuff in a directory" seems perfectly serviceable for that use case already. Tools that *don't* support "just throw it in a directory" as a deployment option are IMO unpythonic -- practicality beats purity, after all. ;-)

3 4