Path: csiph.com!usenet.pasdenom.info!news.redatomik.org!newsfeed.xs4all.nl!newsfeed1a.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail
Return-Path: <ian.g.kelly@gmail.com>
X-Original-To: python-list@python.org
Delivered-To: python-list@mail.python.org
X-Spam-Status: OK 0.042
X-Spam-Evidence: '*H*': 0.93; '*S*': 0.01; 'python3': 0.07; '[0]': 0.09; 'toss': 0.09; 'def': 0.12; '10000000': 0.16; 'internally': 0.16; 'reedy': 0.16; 'skip:t 100': 0.16; 'subject:search': 0.16; 'wrote:': 0.18; 'slightly': 0.19; 'header:In-Reply-To:1': 0.27; 'message-id:@mail.gmail.com': 0.30; 'probably': 0.32; 'skip:d 20': 0.34; 'received:google.com': 0.35; 'to:addr:python-list': 0.38; 'pm,': 0.38; 'to:addr:python.org': 0.39; 'ian': 0.60; 'results.': 0.60; '2015': 0.84; '6.1': 0.84; 'subject:find': 0.84; 'subject:Best': 0.91
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :content-type; bh=Qptegdtl08r2/HL+bvQgbubeK68j97ka5L6eSV664Ew=; b=laR4upvxRzaZxY+DFuvRztREc/YmGO6mkg26lDpBKTpJTsbhcjSumwCspPT8aXIu89 Oasou/JgHIi5Jbbjn20a2Xhh9zKHWiWY4morCEb7m8WXDVZc37SZgw/mTkRPeOgzYwm9 Hnt4/w8LEboDC9nyEwwVthUuNO7Q/jZJVdkOn6Jc3F/EUkiHMl/gz22BH95V7BijVCra stCZMOn7ZVSWYRAtpBMKd4ERPJtJUYX6utTuXiNiWuHrEMd8t/3c7JsPJhAW7C/s2/oc p2QF15XCRv2VEOh5aPDLkvC7qwxgZ5IoGBfIylBtvoyQDm1QUPYH7/W050USwozY87Kh PO4A==
X-Received: by 10.42.164.7 with SMTP id e7mr22242878icy.70.1428434421502; Tue, 07 Apr 2015 12:20:21 -0700 (PDT)
MIME-Version: 1.0
In-Reply-To: <mg1973$lj6$1@ger.gmane.org>
References: <2e3a3c01-20b3-4948-9b32-bd80ed46822b@googlegroups.com> <mailman.93.1428417164.12925.python-list@python.org> <d6e7bb84-3810-435a-bd7a-ad45da86f906@googlegroups.com> <mailman.108.1428424459.12925.python-list@python.org> <9fd13f49-8bfa-43ef-8787-21d5c76a6268@googlegroups.com> <CALwzidnbnbttdd+ow+gYg2-y8KDTAzXfEJ4c19OkEN=eOH2rLw@mail.gmail.com> <mg1973$lj6$1@ger.gmane.org>
From: Ian Kelly <ian.g.kelly@gmail.com>
Date: Tue, 7 Apr 2015 13:19:41 -0600
Subject: Re: Best search algorithm to find condition within a range
To: Python <python-list@python.org>
Content-Type: text/plain; charset=UTF-8
X-BeenThere: python-list@python.org
X-Mailman-Version: 2.1.20
Precedence: list
List-Id: General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe: <https://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: <https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups: comp.lang.python
Message-ID: <mailman.112.1428434424.12925.python-list@python.org>
Lines: 30
NNTP-Posting-Host: 2001:888:2000:d::a6
X-Trace: 1428434424 news.xs4all.nl 2834 [2001:888:2000:d::a6]:34356
X-Complaints-To: abuse@xs4all.nl
Xref: csiph.com comp.lang.python:88611

On Tue, Apr 7, 2015 at 12:55 PM, Terry Reedy <tjreedy@udel.edu> wrote:
> On 4/7/2015 1:44 PM, Ian Kelly wrote:
>
>>>>> def to_base(number, base):
>>
>> ...     digits = []
>> ...     while number > 0:
>> ...         digits.append(number % base)
>> ...         number //= base
>> ...     return digits or [0]
>> ...
>>>>>
>>>>>
>>>>> to_base(2932903594368438384328325832983294832483258958495845849584958458435439543858588435856958650865490,
>>>>> 429496729)
>>
>> [27626525, 286159541, 134919277, 305018215, 329341598, 48181777,
>> 79384857, 112868646, 221068759, 70871527, 416507001, 31]
>> About 15 microseconds.
>
>
> % and probably // call divmod internally and toss one of the results.
> Slightly faster (5.7 versus 6.1 microseconds on my machine) is

Not on my box.

$ python3 -m timeit -s "n = 1000000; x = 42" "n % x; n // x"
10000000 loops, best of 3: 0.105 usec per loop
$ python3 -m timeit -s "n = 1000000; x = 42" "divmod(n,x)"
10000000 loops, best of 3: 0.124 usec per loop