Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!newsfeed.xs4all.nl!newsfeed4a.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 0.009 X-Spam-Evidence: '*H*': 0.98; '*S*': 0.00; 'subject:not': 0.03; 'created,': 0.09; 'here?': 0.09; 'newly': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'windows,': 0.09; 'python': 0.11; 'assume': 0.14; 'be:': 0.16; 'empty.': 0.16; 'received:80.91.229.3': 0.16; 'received:dip0.t-ipconnect.de': 0.16; 'received:plane.gmane.org': 0.16; 'received:t-ipconnect.de': 0.16; 'roy': 0.16; 'sure.': 0.16; 'wrote:': 0.18; 'module': 0.19; 'properly': 0.19; 'header:User- Agent:1': 0.23; 'directory.': 0.24; 'large,': 0.24; 'new,': 0.24; 'fairly': 0.24; 'nearly': 0.26; 'header:X-Complaints-To:1': 0.27; 'unix': 0.29; 'wonder': 0.29; "doesn't": 0.30; 'subject:that': 0.31; 'file': 0.32; 'probably': 0.32; 'could': 0.34; "can't": 0.35; 'no,': 0.35; 'really': 0.36; 'subject:?': 0.36; 'should': 0.36; 'list': 0.37; 'to:addr:python-list': 0.38; 'files': 0.38; 'reported': 0.39; 'to:addr:python.org': 0.39; 'received:org': 0.40; 'how': 0.40; 'tell': 0.60; 'new': 0.61; 'strategy': 0.64; 'between': 0.67; 'determine': 0.67; 'smith': 0.68; 'therefore': 0.72; 'article': 0.77; 'deleted?': 0.84; 'obvious.': 0.84; 'subject:Test': 0.84; 'viable': 0.84; 'wrap.': 0.84; 'lazy': 0.91; 'subject:very': 0.91 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Peter Otten <__peter__@web.de> Subject: Re: Test for an empty directory that could be very large if it is not empty? Date: Thu, 07 Aug 2014 14:06:14 +0200 Organization: None References: Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7Bit X-Gmane-NNTP-Posting-Host: p57bda2d3.dip0.t-ipconnect.de User-Agent: KNode/4.13.2 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: 1407413193 news.xs4all.nl 2885 [2001:888:2000:d::a6]:56259 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:75845 Roy Smith wrote: > In article , > Gregory Ewing wrote: > >> Virgil Stokes wrote: >> > How can I >> > determine if the directory is empty WITHOUT the generation of a list of >> > the file names >> >> Which platform? >> >> On Windows, I have no idea. >> >> On Unix you can't really do this properly without access >> to opendir() and readdir(), which Python doesn't currently >> wrap. >> >> Will the empty directories be newly created, or could they >> be ones that *used* to contain 200000 files that have since >> been deleted? >> >> If they're new or nearly new, you could probably tell from >> looking at the size reported by stat() on the directory. >> The difference between a fresh empty directory and one with >> 200000 files in it should be fairly obvious. >> >> A viable strategy might be: If the directory is very large, >> assume it's not empty. If it's smallish, list its contents >> to find out for sure. > > I wonder if glob.iglob('*') might help here? No, the glob module uses os.listdir() under the hood. Therefore iglob() is lazy for multiple directories only.