Path: csiph.com!usenet.pasdenom.info!gegeweb.org!de-l.enfer-du-nord.net!feeder1.enfer-du-nord.net!newsfeed.eweka.nl!eweka.nl!feeder3.eweka.nl!newsfeed.xs4all.nl!newsfeed3.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 0.000 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'else:': 0.03; 'exception': 0.03; 'try:': 0.07; 'called.': 0.09; 'received:151': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'subject:skip:a 10': 0.09; 'def': 0.10; "'%d": 0.16; '(typeerror,': 0.16; 'above?': 0.16; 'emanuele': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'valueerror):': 0.16; 'helper': 0.17; 'string,': 0.17; "i'd": 0.22; 'task': 0.23; 'raise': 0.24; 'header:User-Agent:1': 0.26; 'header:X-Complaints-To:1': 0.28; 'writes:': 0.29; 'point': 0.31; 'to:addr:python-list': 0.33; 'skip:d 20': 0.34; 'false': 0.35; "won't": 0.35; 'received:org': 0.36; 'except': 0.36; 'should': 0.36; 'skip:p 20': 0.36; 'two': 0.37; 'subject:: ': 0.38; 'to:addr:python.org': 0.39; 'header:Received:5': 0.40; 'price': 0.66; 'quando': 0.84 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Lele Gaifax Subject: Re: Checking for valid date input and convert appropriately Date: Fri, 22 Feb 2013 13:03:39 +0100 Organization: Nautilus Entertainments References: <92536c34-cf00-4497-b646-ab79fa4ee062@googlegroups.com> <5bac38bb-df2e-47b8-96dd-2b1c090959e4@googlegroups.com> <49de0696-b6f6-42ce-9272-79dac37c9605@googlegroups.com> <0065de90-75e4-4a50-b084-be6c8c7e5f23@googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Gmane-NNTP-Posting-Host: 151.62.64.118 User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3.50 (gnu/linux) Cancel-Lock: sha1:YsJJwsxlOllbMrZDmqAI0T7iQfo= 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: 42 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1361534636 news.xs4all.nl 6879 [2001:888:2000:d::a6]:43964 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:39555 Ferrous Cranus writes: > I'am thinking if somehting like the follwoing work: > > if( task and ( price and price.isdigit() and price.__len__() <= 3 ) and ( date and eval( datetime.strptime(date, '%d %m %Y').strftime('%Y-%m-%d') ) ) ): a) you should not (usually) call “dunder methods” directly, as they are (usually) exposed by builtin functions:: obj.__len__() => len(obj) b) what's the point of the eval() call above? When the strptime() succeds, the following strftime() call always returns a string, otherwise it will raise an exception and both the strftime() and the outer eval() won't be called. Should I write the above, I'd go for having two helper functions, for example:: def price_is_valid(price): return price and price.isdigit() and len(price) <= 3 def date_is_valid(date): try: datetime.strptime(date, '%d %m %Y') except (TypeError, ValueError): return False else: return True ... if task and price_is_valid(price) and date_is_valid(date): ... hth, ciao, lele. -- nickname: Lele Gaifax | Quando vivrò di quello che ho pensato ieri real: Emanuele Gaifas | comincerò ad aver paura di chi mi copia. lele@metapensiero.it | -- Fortunato Depero, 1929.