Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder1.news.weretis.net!feeder.erje.net!eu.feeder.erje.net!feeds.phibee-telecom.net!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 0.001 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'subject:Python': 0.06; 'correct.': 0.07; 'tests.': 0.07; "'return": 0.09; 'function,': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'subject:script': 0.09; 'python': 0.11; 'def': 0.12; 'jan': 0.12; '3):': 0.16; 'assignment.': 0.16; 'multiples': 0.16; 'n+1,': 0.16; 'presume': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'reedy': 0.16; 'reusable': 0.16; 'wrote:': 0.18; 'passing': 0.19; 'putting': 0.22; 'print': 0.22; 'header:User-Agent:1': 0.23; 'script': 0.25; 'pass': 0.26; 'header:X-Complaints-To:1': 0.27; 'header:In-Reply-To:1': 0.27; "i'm": 0.30; 'gives': 0.31; 'code': 0.31; 'assert': 0.31; 'prints': 0.31; 'cases': 0.33; 'basic': 0.35; 'test': 0.35; 'add': 0.35; 'doing': 0.36; 'two': 0.37; 'to:addr:python-list': 0.38; 'pm,': 0.38; 'to:addr:python.org': 0.39; 'university': 0.39; 'received:org': 0.40; 'numbers': 0.61; 'received:173': 0.61; 'first': 0.61; 'sum': 0.64; 'skip:+ 10': 0.65; 'between': 0.67; 'subject:this': 0.83; 'cubes': 0.84; 'received:fios.verizon.net': 0.84; 'subject:Check': 0.95 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Terry Reedy Subject: Re: Check if this basic Python script is coded right Date: Sat, 26 Oct 2013 16:16:22 -0400 References: <9716695c-31e3-40a0-b2a4-73b967494107@googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Gmane-NNTP-Posting-Host: pool-173-59-117-133.phlapa.fios.verizon.net User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.0.1 In-Reply-To: <9716695c-31e3-40a0-b2a4-73b967494107@googlegroups.com> 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: 45 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1382818600 news.xs4all.nl 15884 [2001:888:2000:d::a6]:60839 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:57657 On 10/26/2013 1:36 PM, HC wrote: > I'm doing my first year in university and I need help with this basic assignment. > > Assignment: Write Python script that prints sum of cubes of numbers between 0-200 that are multiples of 3. 3^3+6^3+9^3+12^3....+198^3=? > > My script: > count = 0 > answer = 0 > > while count<200: > if count%3==0: > answer = answer + count**3 > count = count + 1 > > print ("Result is: " +str(answer)) > > Is it all okay? Generalize the problem, put the code in a reusable testable function, and start with test cases. -- def sum33(n): "Return sum of cubes of multiples of 3 <= n." for n, sm in ( (0,0), (2,0), (3,27), (4,27), (6,243), ): assert sum33(n) == sm print(sum33(200)) -- This will fail because None != 0. Now add 'return 0' and the first two cases pass and then it fails with None != 27. Now change 'return 0' to answer = 0 for i in range(3, n+1, 3): answer += i*i*i return answer and it will print 131990067, which I presume is correct. Putting your code in the body instead, indented, with '200' replaced with 'n+1', and with 'return answer' added, gives the same result after passing the same tests. -- Terry Jan Reedy