Path: csiph.com!newsfeed.hal-mli.net!feeder3.hal-mli.net!news.stack.nl!newsfeed.xs4all.nl!newsfeed2a.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail
Return-Path: <python-python-list@m.gmane.org>
X-Original-To: python-list@python.org
Delivered-To: python-list@mail.python.org
X-Spam-Status: OK 0.007
X-Spam-Evidence: '*H*': 0.99; '*S*': 0.00; 'prevents': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'typed': 0.09; 'python': 0.11; '[1].': 0.16; '[2].': 0.16; 'expecting': 0.16; 'integer,': 0.16; 'objects.': 0.16; 'ought': 0.16; 'overriding': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'variables,': 0.16; 'wrote:': 0.18; 'header:User-Agent:1': 0.23; 'integer': 0.24; 'pass': 0.26; 'header:X-Complaints-To:1': 0.27; 'function': 0.29; 'chris': 0.29; 'accidentally': 0.31; 'objects': 0.35; 'there': 0.35; 'c++': 0.36; 'raising': 0.36; 'method': 0.36; 'list': 0.37; 'to:addr:python-list': 0.38; 'list,': 0.38; 'to:addr:python.org': 0.39; 'received:org': 0.40; 'called': 0.40; 'different': 0.65; 'risk': 0.72; 'subject:This': 0.74; "class's": 0.84; 'float,': 0.84; 'hopes': 0.91; 'mistakenly': 0.91
X-Injected-Via-Gmane: http://gmane.org/
To: python-list@python.org
From: Sturla Molden <sturla.molden@gmail.com>
Subject: Re: OT: This Swift thing
Date: Thu, 5 Jun 2014 23:08:19 +0000 (UTC)
References: <87tx7zi0i1.fsf@dpt-info.u-strasbg.fr> <lmqn53$4ei$1@ger.gmane.org> <CAPTjJmqswbLV9EOKVcJjRWoFfzry6hLvSOrphSdurB903aFveg@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-Gmane-NNTP-Posting-Host: 109-130-11.connect.netcom.no
User-Agent: NewsTap/4.0.1 (iPad)
X-: 
X-BeenThere: python-list@python.org
X-Mailman-Version: 2.1.15
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.10784.1402009809.18130.python-list@python.org>
Lines: 25
NNTP-Posting-Host: 2001:888:2000:d::a6
X-Trace: 1402009809 news.xs4all.nl 2833 [2001:888:2000:d::a6]:37708
X-Complaints-To: abuse@xs4all.nl
Xref: csiph.com comp.lang.python:72786

Chris Angelico <rosuav@gmail.com> wrote:

> "Type safety" means many different things to different people. What
> Python has is untyped variables, and hierarchically typed objects.
> It's impossible to accidentally treat an integer as a float, and have
> junk data [1]. It's impossible to accidentally call a base class's
> method when you ought to have called the overriding method in the
> subclass, which is a risk in C++ [2]. 

Exactly.

I have no hopes that those who claim Python lacks type safety will
understand this, however.


> If you mistakenly pass a list to
> a function that was expecting an integer, that function will *know*
> that it got a list, because objects in Python are rigidly typed.
  
And then there is nothing that prevents the function from raising a
TypeError.


Sturla