Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.lang.python > #25371

Re: Request for useful functions on dicts

Path csiph.com!usenet.pasdenom.info!news.albasani.net!newsfeed.freenet.ag!news2.euro.net!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail
Return-Path <leif.poorman@gmail.com>
X-Original-To python-list@python.org
Delivered-To python-list@mail.python.org
X-Spam-Status OK 0.002
X-Spam-Evidence '*H*': 1.00; '*S*': 0.00; 'argument': 0.04; 'suggestions,': 0.07; 'python': 0.09; 'none.': 0.09; 'subset': 0.09; 'to:addr:comp.lang.python': 0.09; 'cc:addr:python-list': 0.10; 'def': 0.10; 'pushed': 0.13; 'intersection': 0.16; 'operation.': 0.16; 'pythonic': 0.16; 'timed': 0.16; 'saying': 0.18; 'code.': 0.20; 'written': 0.20; 'bit': 0.21; 'thanks.': 0.21; "haven't": 0.23; 'cc:no real name:2**0': 0.24; 'cc:2**1': 0.24; 'cc:addr:python.org': 0.25; 'header:In-Reply-To:1': 0.25; 'header:User-Agent:1': 0.26; 'wrote': 0.26; 'common': 0.26; 'cc:addr:gmail.com': 0.27; 'implemented': 0.27; 'faster,': 0.29; 'idea,': 0.29; 'sets.': 0.29; 'case,': 0.29; "i'm": 0.29; 'e.g.': 0.30; 'could': 0.32; 'received:google.com': 0.34; 'thanks': 0.34; 'faster': 0.35; 'received:209.85': 0.35; 'really': 0.36; 'smaller': 0.36; '(for': 0.37; 'quite': 0.37; 'received:209': 0.37; 'received:209.85.216': 0.37; 'subject:: ': 0.38; 'object': 0.38; 'where': 0.40; 'your': 0.60; 'most': 0.61; 'skip:n 10': 0.63; 'received:209.85.216.184': 0.84; 'deal,': 0.93
Newsgroups comp.lang.python
Date Sun, 15 Jul 2012 12:47:26 -0700 (PDT)
In-Reply-To <mailman.2146.1342373918.4697.python-list@python.org>
Complaints-To groups-abuse@google.com
Injection-Info glegroupsg2000goo.googlegroups.com; posting-host=76.97.43.12; posting-account=-rDhLQoAAABniRdj0n3RqIriCs8wG4fD
References <38c6d4cb-89b3-4f78-a966-be5ddccec845@googlegroups.com> <mailman.2146.1342373918.4697.python-list@python.org>
User-Agent G2/1.0
X-Google-Web-Client true
X-Google-IP 76.97.43.12
MIME-Version 1.0
Subject Re: Request for useful functions on dicts
From Leif <leif.poorman@gmail.com>
To comp.lang.python@googlegroups.com
Content-Type text/plain; charset=ISO-8859-1
Content-Transfer-Encoding quoted-printable
Cc python-list@python.org, Leif <leif.poorman@gmail.com>
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>
Message-ID <mailman.2151.1342381649.4697.python-list@python.org> (permalink)
Lines 27
NNTP-Posting-Host 2001:888:2000:d::a6
X-Trace 1342381649 news.xs4all.nl 6928 [2001:888:2000:d::a6]:38165
X-Complaints-To abuse@xs4all.nl
Xref csiph.com comp.lang.python:25371

Show key headers only | View raw


Thanks for the suggestions, Ian!  I implemented most of them and pushed the code.

> That&#39;s because the Pythonic way is to either create a new object and
> return it, or mutate the existing object and return None.

You're saying what I was already thinking.

> In Python 2.7+, intersection and difference could be written using
> dictviews, which act like sets.

I'm debating with myself right now whether to support 2.5 and 2.6.

> def partition(f, d):

Good idea, thanks.

> issubdict could be implemented as a subset operation.  I haven&#39;t timed

The current implementation is a bit faster, and it's quite a bit faster on the common (for me) case, where one argument is much smaller than the other.  I wrote it that way because if m=len(first), n=len(second), the amount of work is O(min(m,n)).  Your implementation is O(m + n).  Not really a big deal, unless e.g. m << n. 

--Leif

Back to comp.lang.python | Previous | NextPrevious in thread | Find similar | Unroll thread


Thread

Request for useful functions on dicts Leif <leif.poorman@gmail.com> - 2012-07-14 16:56 -0700
  Re: Request for useful functions on dicts Ian Kelly <ian.g.kelly@gmail.com> - 2012-07-15 11:38 -0600
    Re: Request for useful functions on dicts Leif <leif.poorman@gmail.com> - 2012-07-15 12:47 -0700
    Re: Request for useful functions on dicts Leif <leif.poorman@gmail.com> - 2012-07-15 12:47 -0700

csiph-web