Path: csiph.com!optima2.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!1.eu.feeder.erje.net!newsfeed.fsmpi.rwth-aachen.de!newsfeed.straub-nv.de!eternal-september.org!feeder.eternal-september.org!mx02.eternal-september.org!.POSTED!not-for-mail From: Rob Gaddi Newsgroups: comp.lang.python Subject: Re: Python Questions - July 25, 2015 Date: Tue, 28 Jul 2015 18:46:30 +0000 (UTC) Organization: A noiseless patient Spider Lines: 29 Message-ID: References: <2adac4ce-976f-4a8a-849d-c76e484eba77@googlegroups.com> <55b7a9f5$0$1668$c3e8da3$5496439d@news.astraweb.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Injection-Date: Tue, 28 Jul 2015 18:46:30 +0000 (UTC) Injection-Info: mx02.eternal-september.org; posting-host="04547d38cef46905d62dbfd151cc4bea"; logging-data="21235"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18G0J6MyajguCn4j9KmvPjh" User-Agent: Pan/0.139 (Sexual Chocolate; GIT bf56508 git://git.gnome.org/pan2) Cancel-Lock: sha1:b4YbaiSMIf1YO/PT5YicGXVJ3uU= Xref: csiph.com comp.lang.python:94703 On Tue, 28 Jul 2015 17:45:00 +0100, BartC wrote: > On 28/07/2015 17:12, Steven D'Aprano wrote: >> On Tue, 28 Jul 2015 07:46 pm, BartC wrote: >> >>> (I'm still reeling from the size of that Anaconda download. Apparently >>> it contains a whole bunch of stuff, nothing to do with numpy, that I >>> don't need. But one of the listed packages was 'libffi', which is >>> puzzling. This library lets a C-like language call functions with >>> runtime-determined argument types. How would that be used in Python?) >> >> https://en.wikipedia.org/wiki/Libffi > > Yes, I know (I was looking at it myself a few days ago for another > project). But while it might be used for implementing some of Python's > internals, I was wondering what it was doing in a user-level set of > libraries, given that it's mostly a bunch of C code. > > Perhaps they were just padding the list to make it look more impressive. It underpins the ctypes implementation, which is neither here nor there. If I remember right, numpy does dynamic loading of one of a couple different (FORTRAN?) algebra libraries depending on which ones it can find installed. That would be a pretty clear use case for libffi. -- Rob Gaddi, Highland Technology -- www.highlandtechnology.com Email address domain is currently out of order. See above to fix.