Path: csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail From: Joel Goldstick Newsgroups: comp.lang.python Subject: Re: General computer language, syntax question. Date: Mon, 29 Feb 2016 08:55:19 -0500 Lines: 59 Message-ID: References: <5b619ffa-aae6-4fa8-9f62-58532668ec93@googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Trace: news.uni-berlin.de I01nOJ1QoReSSeCSGKumxAxl0Ci6sRXo5dtc3s1qIgpA== 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; 'received:209.85.223': 0.03; 'skip:[ 20': 0.03; 'javascript,': 0.07; 'cc:addr:python- list': 0.09; '"if': 0.09; 'empty,': 0.09; 'subject:language': 0.09; 'python': 0.10; '>>>': 0.15; 'skip:1 30': 0.15; '2016': 0.16; 'boolean': 0.16; 'cyclic': 0.16; 'empty.': 0.16; 'exhausted': 0.16; 'javascript"': 0.16; 'nodes': 0.16; 'received:io': 0.16; 'received:psf.io': 0.16; 'wrote:': 0.16; 'element': 0.18; 'email addr:gmail.com>': 0.18; '>>>': 0.20; 'cc:2**0': 0.20; 'cc:addr:python.org': 0.20; 'programming': 0.22; 'am,': 0.23; 'feb': 0.23; 'header:In-Reply-To:1': 0.24; 'feature': 0.24; 'mon,': 0.24; 'script': 0.25; 'message-id:@mail.gmail.com': 0.27; 'entries': 0.27; "skip:' 10": 0.28; 'skip:( 20': 0.28; 'node': 0.29; 'subset': 0.29; 'array': 0.29; 'print': 0.30; 'url:mailman': 0.30; 'skip:[ 10': 0.31; 'problem': 0.33; 'url:python': 0.33; 'lock': 0.33; 'url:listinfo': 0.34; 'languages': 0.34; 'add': 0.34; 'received:google.com': 0.35; 'false': 0.35; 'but': 0.36; 'list,': 0.36; 'should': 0.36; 'instead': 0.36; 'there': 0.36; 'url:org': 0.36; 'possible.': 0.36; 'received:209.85': 0.36; 'skip:{ 10': 0.36; 'subject:: ': 0.37; 'really': 0.37; 'skip:& 10': 0.37; 'turn': 0.37; 'list.': 0.37; 'seem': 0.37; 'received:209': 0.38; 'sure': 0.39; 'url:mail': 0.40; 'more': 0.63; 'due': 0.65; 'beautiful': 0.66; 'url:info': 0.71; 'lack': 0.76; 'networks,': 0.79; 'madness.': 0.84; 'subject:General': 0.84; 'joel': 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:to :cc; bh=kHDQ9lJQQlmiYapfYvpOAl8VjzjUnpVaK61ZLLbFBtE=; b=03QBEKRJ8h/ru7ObKVRasDVP86+GSfDvtojnoF2iY6Drc8PsVfVu/PJNIJ4AgtUYRU /XCDX37M2vkBzS6O+NXg/frj6GCWdtUKfZDzxa5ujmxIVnBpyHhWOcfnCTdJ7gmNzfnS XoQ3ZtwORzemqRKf0d6ndwayzOaejXUVKVa6MylliLTSlB27s8K9xCoIRslnYi7B5ouM Re50eE1rmlefnsyZb9rISTi8BpBCt0m5SIeKpKcYyePaeStWbCiehbdWEDMiSA2si/y3 Y9LJeE1D9NwxAbSL2FW+97FM2VOJez/cWcjMg2VCZERArAn1PpLndEpugSuwmYl8wWzl 2Dmg== 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:to:cc; bh=kHDQ9lJQQlmiYapfYvpOAl8VjzjUnpVaK61ZLLbFBtE=; b=Aem6OH0qtVOGV2DH7+KsPSFcsVVBSTF8jx4Ul8QhSFgjW6fiDz6bz///KFrJhJzT8p XIdWPAESKQ0i4nj7Z4kQMEYYtE61BY0K0vSOD5ODt19Qk/Ed0JOZvkcmcHCoGh6tWIIk /D4FuCwi3Ui/bpqtYKmNB2hlAIHuUjdhf3/zx+NQ5+PRwPMnEcsbDrMkhjKlKLk5/7Dz sISMxcleRQ2Bh9e25COYYq2Wx8hOqerYsUQIYcRK1VrVI9KzkHZEyfwe+AA9GiL6XrPP 40M46TgkfrN2k/Pq/tmIqAX1Th/ro3EFCzICN2nRhyL81JOu0H1qWlMC2NwSUrVxhwYu Ns6A== X-Gm-Message-State: AG10YOQd6bIG7skx8rIhevtNqtt9XoBO+X0KkvVzDCmH6J4amC5FmPro9C046ziEJxKKd4IqhM2IgUYNcsl1jA== X-Received: by 10.107.10.147 with SMTP id 19mr17962488iok.46.1456754119927; Mon, 29 Feb 2016 05:55:19 -0800 (PST) In-Reply-To: <5b619ffa-aae6-4fa8-9f62-58532668ec93@googlegroups.com> X-Content-Filtered-By: Mailman/MimeDel 2.1.21 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:103711 On Mon, Feb 29, 2016 at 8:45 AM, wrote: > I have a problem programming uniform networks, "x nodes with y links" that > turn out to be really hairy to solve for me and i feel i really lack the > programming features > > "Actually i program in javascript" but the problem seem general for all > programming languages including Pyhton. > > For a beautiful solution it would require "If in list/array return > boolean" "If not in list/array return boolean". > > But there is no such feature Python nor Javascript, so instead i set > boolean value "inlist" to false and loop thru, to see if it is already in > list. If not it is added to list. > > So if the current node i generate links for is x and i try to generate a > link to node z, and z's links exhausted i will add it to exhausted list. > > And if there is node-x exhausted entries in list, well then script should > break because it will lock into a cycle. The cyclic lockup is due to only a > subset of the networks on the form (links*deep)+1=nodes is possible. > > So what i need is to know howto write "if list/array ***empty*** do > {something}" > > I sure know howto check if an array have 1 element 2,3,4 but how do you > check for empty. > > I think it is crazy that you can not do general comparissons of the type > If in list/array > If not in list/array > > But it is even more crazy that you can not check if list/array is empty, > that is just madness. > -- > https://mail.python.org/mailman/listinfo/python-list > >>> l = [1,2,3,4] >>> if 1 in l: ... print 1 ... 1 >>> if 6 in l: ... print 1 ... >>> >>> l = [] >>> if len(l) == 0: ... print 'empty' ... empty -- Joel Goldstick http://joelgoldstick.com/ http://cc-baseballstats.info/