Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.002 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'scipy': 0.05; 'wednesday,': 0.07; 'subject:How': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'wrong,': 0.09; 'python': 0.10; 'jan': 0.11; 'output': 0.13; 'file,': 0.15; 'things.': 0.15; 'display,': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'reedy': 0.16; 'snippets': 0.16; 'wrote:': 0.16; '2015': 0.20; 'function,': 0.22; 'trying': 0.22; 'am,': 0.23; 'code.': 0.23; 'import': 0.24; 'header:In-Reply-To:1': 0.24; 'all.': 0.24; 'header:User-Agent:1': 0.26; 'header:X-Complaints-To:1': 0.26; 'define': 0.27; 'idea': 0.28; 'sure,': 0.29; "i'm": 0.30; 'code': 0.30; "can't": 0.32; 'though,': 0.32; 'run': 0.33; 'running': 0.34; 'gets': 0.35; 'but': 0.36; 'to:addr:python-list': 0.36; 'subject:?': 0.36; 'subject:: ': 0.37; 'received:org': 0.37; 'doing': 0.38; "won't": 0.38; 'why': 0.39; "didn't": 0.39; 'rather': 0.39; 'to:addr:python.org': 0.40; 'easy': 0.60; 'show': 0.62; 'further': 0.62; 'sample': 0.63; 'benefit': 0.66; 'book.': 0.72; 'obvious': 0.76; '2.7.': 0.84; 'utc-4,': 0.84; 'received:fios.verizon.net': 0.91 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Terry Reedy Subject: Re: How to Calculate NPV? Date: Wed, 29 Jul 2015 15:08:25 -0400 References: <249a5b7e-0364-4b74-94f4-c8bbfbba2479@googlegroups.com> <757d1a56-fc27-4996-acff-8bb7e07204d6@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-98-114-97-173.phlapa.fios.verizon.net User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 In-Reply-To: <757d1a56-fc27-4996-acff-8bb7e07204d6@googlegroups.com> X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.20+ 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: 26 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1438196929 news.xs4all.nl 2857 [2001:888:2000:d::a6]:45408 X-Complaints-To: abuse@xs4all.nl Path: csiph.com!usenet.pasdenom.info!news.stben.net!border1.nntp.ams1.giganews.com!border2.nntp.ams1.giganews.com!nntp.giganews.com!newsfeed.xs4all.nl!newsfeed8.news.xs4all.nl!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail Xref: csiph.com comp.lang.python:94750 On 7/29/2015 10:21 AM, ryguy7272 wrote: > On Wednesday, July 29, 2015 at 9:59:10 AM UTC-4, ryguy7272 wrote: >> I am using Spyder Python 2.7. I'm running this sample code. >> >> import scipy as sp >> cashflows=[50,40,20,10,50] >> npv=sp.npv(0.1,cashflows) >> round(npv,2) >> >> >> Now, I'm trying to get the NPV, and I don't see any obvious way to get it. >> The author of the book that I'm reading gets 144.56. I think that's wrong, but I don't know for sure, as Python won't do any calculation at all. It's easy to enter code and run it, but I can't tell how to get Python to actually DO the calculation. >> >> Any idea what I'm doing wrong? > > PERFECT!! SO SIMPLE!! > I don't know why the author didn't do that in the book. The book show you how to calculate things. It is up to you to display, output to a file, or use in further calculation. I do admit, though, that snippets that show how to use an existing function, rather than define a new function, might benefit from adding print(xxxx). -- Terry Jan Reedy