Path: csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail
From: MRAB <python@mrabarnett.plus.com>
Newsgroups: comp.lang.python
Subject: Re: Assignment Versus Equality
Date: Sun, 26 Jun 2016 16:41:48 +0100
Lines: 16
Message-ID: <mailman.6.1466955713.2358.python-list@python.org>
References: <8a53c069-ca13-47bf-a24e-d2393a018b22@googlegroups.com> <nkobtu$gaq$1@dont-email.me> <78b5ed0e-ec5f-6f54-b88c-4fed570115d2@mrabarnett.plus.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
X-Trace: news.uni-berlin.de FroxDHrNnRK435H3bJOZOAEfY+MNru1h8GeDzYxSi4dg==
Return-Path: <python@mrabarnett.plus.com>
X-Original-To: python-list@python.org
Delivered-To: python-list@mail.python.org
X-Spam-Status: OK 0.003
X-Spam-Evidence: '*H*': 0.99; '*S*': 0.00; 'assignment': 0.07; 'python': 0.10; '"="': 0.16; 'assignments.': 0.16; 'assigns': 0.16; 'chained': 0.16; 'comparison.': 0.16; 'expressions.': 0.16; 'from:addr:mrabarnett.plus.com': 0.16; 'from:addr:python': 0.16; 'from:name:mrab': 0.16; 'message-id:@mrabarnett.plus.com': 0.16; 'ops': 0.16; 'received:192.168.1.4': 0.16; 'received:84.93': 0.16; 'received:84.93.230': 0.16; 'received:io': 0.16; 'received:psf.io': 0.16; 'wrote:': 0.16; 'copied': 0.18; 'lawrence': 0.22; 'header:In-Reply-To:1': 0.24; 'header:User- Agent:1': 0.26; 'appear': 0.26; 'equality': 0.29; "i'm": 0.30; 'convention': 0.30; "can't": 0.32; 'received:84': 0.32; 'common': 0.33; 'though.': 0.33; 'supports': 0.35; 'to:addr:python-list': 0.36; 'subject:: ': 0.37; 'why': 0.39; 'sure': 0.39; 'received:192': 0.39; 'to:addr:python.org': 0.40; 'skip:u 10': 0.61; 'virtually': 0.66; 'mistakes.': 0.84; 'mistakes': 0.95
X-CM-Score: 0.00
X-CNFS-Analysis: v=2.2 cv=QfYkhYTv c=1 sm=1 tr=0 a=0nF1XD0wxitMEM03M9B4ZQ==:117 a=0nF1XD0wxitMEM03M9B4ZQ==:17 a=IkcTkHD0fZMA:10 a=XrjwwsNLl7gUBfuciHQA:9
X-AUTH: mrabarnett@:2500
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.1.1
In-Reply-To: <nkobtu$gaq$1@dont-email.me>
X-BeenThere: python-list@python.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe: <https://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive: <http://mail.python.org/pipermail/python-list/>
List-Post: <mailto:python-list@python.org>
List-Help: <mailto:python-list-request@python.org?subject=help>
List-Subscribe: <https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
X-Mailman-Original-Message-ID: <78b5ed0e-ec5f-6f54-b88c-4fed570115d2@mrabarnett.plus.com>
X-Mailman-Original-References: <8a53c069-ca13-47bf-a24e-d2393a018b22@googlegroups.com> <nkobtu$gaq$1@dont-email.me>
Xref: csiph.com comp.lang.python:110522

On 2016-06-26 11:48, BartC wrote:
> On 26/06/2016 08:36, Lawrence D’Oliveiro wrote:
>> One of Python’s few mistakes was that it copied the C convention of using “=” for assignment and “==” for equality comparison.
>
> One of C's many mistakes. Unfortunately C has been very influential.
>
> However, why couldn't Python have used "=" both for assignment, and for
> equality? Since I understand assignment ops can't appear in expressions.
>
[snip]

Python supports chained assignments. For example, "a = b = 0" assigns 0 
to both a and b.

I'm not sure how common it is, though. I virtually never use it myself.