Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!feeds.phibee-telecom.net!newsfeed.xs4all.nl!newsfeed3.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!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 0.032 X-Spam-Evidence: '*H*': 0.94; '*S*': 0.00; 'subject:not': 0.03; 'that?': 0.05; 'suppose': 0.07; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'empty.': 0.16; 'finney': 0.16; 'measured': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'simplest': 0.16; 'thereby': 0.16; 'header:User-Agent:1': 0.23; 'certainly': 0.24; 'entries': 0.24; 'extension': 0.26; 'header:X-Complaints-To:1': 0.27; 'directory,': 0.31; 'subject:that': 0.31; 'writes:': 0.31; 'file': 0.32; '(e.g.': 0.33; 'something': 0.35; 'test': 0.35; 'subject:?': 0.36; 'should': 0.36; 'too': 0.37; 'list': 0.37; 'performance': 0.37; 'skip:o 20': 0.38; 'ben': 0.38; 'to:addr:python-list': 0.38; 'to:addr:python.org': 0.39; 'either': 0.39; 'received:org': 0.40; 'how': 0.40; '8bit%:29': 0.60; 'dangerous': 0.60; 'most': 0.60; 'decided': 0.64; 'more': 0.64; 'determine': 0.67; 'goal': 0.75; 'himself,': 0.84; 'prevailing': 0.84; 'received:125': 0.84; 'subject:Test': 0.84; 'subject:very': 0.91; '\xe2\x80\x9cthe': 0.91 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Ben Finney Subject: Re: Test for an empty directory that could be very large if it is not empty? Date: Thu, 07 Aug 2014 08:26:49 +1000 References: <53E2A22A.10906@it.uu.se> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Gmane-NNTP-Posting-Host: jigong.madmonks.org X-Public-Key-ID: 0xAC128405 X-Public-Key-Fingerprint: 517C F14B B2F3 98B0 CB35 4855 B8B2 4C06 AC12 8405 X-Public-Key-URL: http://www.benfinney.id.au/contact/bfinney-pubkey.asc X-Post-From: Ben Finney User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) Cancel-Lock: sha1:mMWH4qQZ+0OLwyUH2fJUZ2Ez0Y4= 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: 22 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1407364031 news.xs4all.nl 2873 [2001:888:2000:d::a6]:58771 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:75814 Virgil Stokes writes: > Suppose I have a directory C:/Test that is either empty or contains > more than 2000000 files, all with the same extension (e.g. *.txt). How > can I determine if the directory is empty WITHOUT the generation of a > list of the file names in it (e.g. using os.listdir('C:/Test')) when > it is not empty? What is your goal for that? Have you measured the performance difference and decided *based on objective observation* that it's too expensive? Certainly ‘os.listdir(foo)’ is the simplest way to determine the entries in a directory, and thereby to test whether it is empty. That simplicity is very valuable, and you should have a compelling, *measured* reason to do something more complicated. What is it? -- \ “The most dangerous man to any government is the man who is | `\ able to think things out for himself, without regard to the | _o__) prevailing superstitions and taboos.” —Henry L. Mencken | Ben Finney