Path: csiph.com!usenet.pasdenom.info!aioe.org!news.stack.nl!newsfeed.xs4all.nl!newsfeed1.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.001 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'explicitly': 0.05; 'correct.': 0.07; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'def': 0.12; '(self):': 0.16; 'charles': 0.16; 'col': 0.16; 'container,': 0.16; 'doubly': 0.16; 'fine.': 0.16; 'generator.': 0.16; 'iteration': 0.16; 'posting,': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'such,': 0.16; 'all.': 0.16; 'wrote:': 0.18; 'trying': 0.19; 'header:User-Agent:1': 0.23; 'received:comcast.net': 0.24; "i've": 0.25; 'nearly': 0.26; 'header:X-Complaints-To:1': 0.27; 'header:In-Reply-To:1': 0.27; 'correct': 0.29; 'raise': 0.29; "doesn't": 0.30; "i'm": 0.30; 'code': 0.31; 'says': 0.33; 'url:python': 0.33; 'skip:_ 10': 0.34; 'indexed': 0.36; 'yield': 0.36; 'url:org': 0.36; 'should': 0.36; 'url:library': 0.38; 'to:addr:python-list': 0.38; 'pm,': 0.38; 'to:addr:python.org': 0.39; 'received:org': 0.40; 'called': 0.40; 'how': 0.40; 'remove': 0.60; 'url:3': 0.61; 'charset:windows-1252': 0.65; 'statement,': 0.68; 'batchelder': 0.84; 'subject:skip:S 10': 0.84 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Ned Batchelder Subject: Re: __next__ and StopIteration Date: Mon, 09 Feb 2015 20:30:21 -0500 References: <54D9072F.3010904@earthlink.net> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Gmane-NNTP-Posting-Host: c-50-133-228-126.hsd1.ma.comcast.net User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 In-Reply-To: X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 36 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1423531834 news.xs4all.nl 2873 [2001:888:2000:d::a6]:35926 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:85419 On 2/9/15 2:24 PM, Ned Batchelder wrote: > On 2/9/15 2:14 PM, Charles Hixson wrote: >> I'm trying to write a correct iteration over a doubly indexed container, >> and what I've got so far is: def __next__ (self): >> for row in range(self._rows): >> for col in range(self._cols): >> if self._grid[row][col]: >> yield self._grid[row][col] >> #end if >> #end for col >> #end for row >> raise StopIteration >> >> What bothers me is that it doesn't look like it would continue to raise >> StopIteration if it were called again, which is what >> https://docs.python.org/3/library/stdtypes.html#iterator.__next__ says >> is correct. How should this be fixed? > > You are using yield, which means __next__ is a generator. As such, you > don't have to explicitly raise StopIteration at all. Just remove that > statement, and you should be fine. > > Also, look into how you are posting, the code is nearly mangled. :( > Oops, __next__ isn't right here, it should be __iter__: def __iter__(self): for row in range(self._rows): for col in range(self._cols): if self._grid[row][col]: yield self._grid[row][col] -- Ned Batchelder, http://nedbatchelder.com