Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!aioe.org!feeder.news-service.com!newsfeed.xs4all.nl!newsfeed5.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail
Return-Path: <ericsnowcurrently@gmail.com>
X-Original-To: python-list@python.org
Delivered-To: python-list@mail.python.org
X-Spam-Status: OK 0.014
X-Spam-Evidence: '*H*': 0.97; '*S*': 0.00; 'python.': 0.04; 'cpython': 0.05; 'subject:Python': 0.06; 'definitions': 0.07; 'imports': 0.07; 'python': 0.08; 'subject:features': 0.09; 'to:name:python- list': 0.19; 'language': 0.21; 'objects,': 0.23; 'pieces': 0.23; 'libraries': 0.25; 'expect': 0.25; 'moving': 0.25; 'function': 0.26; 'thanks.': 0.26; 'message-id:@mail.gmail.com': 0.28; 'class': 0.31; 'least': 0.31; 'pure': 0.32; 'to:addr:python-list': 0.34; 'that,': 0.35; 'optimization': 0.36; 'received:google.com': 0.37; 'received:209.85': 0.38; 'could': 0.38; 'think': 0.38; 'to:addr:python.org': 0.39; 'received:209': 0.39; 'here': 0.66; 'due': 0.66; 'received:209.85.215.174': 0.67; 'received:mail- ey0-f174.google.com': 0.67; 'heavy': 0.71; 'performance:': 0.84; 'contrast': 0.91
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:date:message-id:subject:from:to :content-type; bh=WL3wD62zFd1Lu85og+D0FILgeXINH5FBmFhwTAw4E/4=; b=YZhgY0XyE+3BHm7r/47OXGFDvIq2ZuOuNgJeNFRanqqaAOYsMFEcXxBJEnQn/eutth NLtiMyUarIjoPTNjComuaSzYMhyeb9kLHy97c7tkGOUkWkd3PrJ8sCScX3LqCvJyIdc2 6vNfAIV1TQJdZ9PWats+8Fx/d3EfaWkhbUjpQ=
DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type; b=jiGdyHwy92Vz1JA2qQgxl9QsxiXB0G5iHNpE4OZ2B2WRQIEOsE8CDEXckxrdiBSky3 7ELZBt57AFPM42o303KHdpS/m3uTgworH0M5SgM085+Jamx4eK/25WrWdJjtPiwC7jV7 GaZV2iVNLh4q8RHUi59JfkDHVxLX5v17nS3c0=
MIME-Version: 1.0
Date: Thu, 23 Jun 2011 10:58:06 -0600
Subject: performance critical Python features
From: Eric Snow <ericsnowcurrently@gmail.com>
To: python-list <python-list@python.org>
Content-Type: text/plain; charset=ISO-8859-1
X-BeenThere: python-list@python.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe: <http://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive: <http://mail.python.org/pipermail/python-list>
List-Post: <mailto:python-list@python.org>
List-Help: <mailto:python-list-request@python.org?subject=help>
List-Subscribe: <http://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups: comp.lang.python
Message-ID: <mailman.330.1308848288.1164.python-list@python.org>
Lines: 25
NNTP-Posting-Host: 82.94.164.166
X-Trace: 1308848288 news.xs4all.nl 14144 [::ffff:82.94.164.166]:56412
X-Complaints-To: abuse@xs4all.nl
Xref: x330-a1.tempe.blueboxinc.net comp.lang.python:8313

I was thinking about the different features of Python that have an
impact on performance.  Here are the obvious ones I could think of:

Features most impactful on performance:

- function calls
- loops

Features least impactful on performance:

- imports
- function definitions
- class definitions

A key point is that CPython has special-case optimization for
functions (code objects, locals, and eval) and loops (comprehensions,
generators, and iterators).  Also, other libraries are optimized via
C-extensions to be efficient, I expect due to their use in loops.  In
contrast to that, the machinery behind language features like imports
are moving to pure Python.

So, which are the other pieces of Python that really need the heavy
optimization and which are those that don't?  Thanks.

-eric