Path: csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail From: Chris Angelico Newsgroups: comp.lang.python Subject: Re: Strange range Date: Sat, 2 Apr 2016 01:45:00 +1100 Lines: 33 Message-ID: References: <87y48xjwqq.fsf@elektro.pacujo.net> <56fe76f2$0$22141$c3e8da3$5496439d@news.astraweb.com> <87lh4xjt37.fsf@elektro.pacujo.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Trace: news.uni-berlin.de wuLtxCHcUv7JasRYWeQ35AmV6ubHRwBpJJHA9zsTASEQ== Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.013 X-Spam-Evidence: '*H*': 0.97; '*S*': 0.00; 'cc:addr:python-list': 0.09; 'itself.': 0.11; 'index': 0.13; '2016': 0.16; 'from:addr:rosuav': 0.16; 'from:name:chris angelico': 0.16; 'iterators': 0.16; 'no;': 0.16; 'received:io': 0.16; 'received:psf.io': 0.16; 'wrote:': 0.16; 'odd': 0.18; '>>>': 0.20; 'cc:2**0': 0.20; 'cc:addr:python.org': 0.20; 'am,': 0.23; 'sat,': 0.23; 'header:In-Reply-To:1': 0.24; "doesn't": 0.26; 'chris': 0.26; 'message-id:@mail.gmail.com': 0.27; "can't": 0.32; 'except': 0.34; 'received:google.com': 0.35; 'false': 0.35; 'level': 0.35; 'received:209.85': 0.36; 'subject:: ': 0.37; 'received:209.85.213': 0.37; 'seem': 0.37; 'received:209': 0.38; 'test': 0.39; 'within': 0.64; 'chrisa': 0.84; 'destructive': 0.84; 'to:none': 0.91 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:cc; bh=S9MRBMW44POK8H1ai6h1cO8za4zrIPdpIdb29x1S/3o=; b=QoS4LP4SZcOL/tJtXKyWi4rMsB6E5T+msImkFPDDKI/j5igTOqrTJ8HgaSrFbGXKh0 CGwWByunpEL7ksgE2oOAaaEq14oypGh1IlpUlLJ8SAR4EH87SLVH0bIRTGNULd44M5Ej zwGiSYz+/V28BlOdASJXSYZGajTc7OcVWgKa37G5EdqlSQ+UmWB/xtaYXKOMaPevugWe JIzHuCE1b3L6eEBrB3/ZrR99gEsFV71087mC6W+0Tw5ZajHrcoFBTgYmwOmuQtv04cBQ 9z5MpeR+mkHCcMMjEN52VjigxDKVrWnJfcsjoxVT1IteCYiRy7t0CRrBflXN2px888/X C1yg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:cc; bh=S9MRBMW44POK8H1ai6h1cO8za4zrIPdpIdb29x1S/3o=; b=LVaBm3L8Js+t+1j6firA67QvdTr9XMrfWKHpknOecnQ58t+Meow/Sf3NenFT81We5X QfLr7WF6LXcqR9dyxaQrBauTjlOy82aKVadrJ5dWR9YqhuTUU9TYOWfMXditrukPEB1L 0KrQYZPchW56hosTG9l6Xh/rbDXVFRSblAOeZ93E3lUHSeeLm+gHKsdGoR7E5ZvIuJbP NwpDNFU4F/cEzamOOWxe4CwbrymYmwRTqVH3cY0NgwamLILczoX+SUhgp3OnqjGSVY2K SjFJ5fICcdF6/1gegpL5hb8JwaCC7WoMCaA2hJsx2BlZP4RvwGz5sNDhC4NDjbXuTKWn qo0g== X-Gm-Message-State: AD7BkJJu5r7+vPb3JT4Vb/TAoQXJngPknHLwwmm5NMdD2mA/ckPJULNTpWcqak6OZTfuQJZOP1zcP9UGRputEQ== X-Received: by 10.51.17.34 with SMTP id gb2mr3928414igd.13.1459521900972; Fri, 01 Apr 2016 07:45:00 -0700 (PDT) In-Reply-To: <87lh4xjt37.fsf@elektro.pacujo.net> X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Xref: csiph.com comp.lang.python:106234 On Sat, Apr 2, 2016 at 1:34 AM, Marko Rauhamaa wrote: > Chris Angelico : > >> *A range object is not an iterator.* > > We now have learned as much. > > However, doesn't that extra level of indirection seem like an odd > choice? No; a range object is an entity in itself. You can test if something's within the range: >>> 5 in range(2,10) True >>> 5 in range(2,10,2) False You can ask how many numbers are in the range: >>> len(range(2,10,2)) 4 You can even ask what position a number would be in, if you index through the range: >>> range(3,100,3).index(57) 18 Iterators can't do any of this, except the 'in' check, which is destructive and O(N). ChrisA