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Groups > comp.lang.python > #80632
| From | Marko Rauhamaa <marko@pacujo.net> |
|---|---|
| Newsgroups | comp.lang.python |
| Subject | Re: I love assert |
| Date | 2014-11-12 23:41 +0200 |
| Organization | A noiseless patient Spider |
| Message-ID | <87a93wqeq3.fsf@elektro.pacujo.net> (permalink) |
| References | <96c138e4-ab95-4e5f-a0c8-e696b5a926bb@googlegroups.com> <cf68f3b4-3312-4dda-a224-8f30f7b31b55@googlegroups.com> |
Anton <anton.schattenfeld@gmail.com>:
> I am not sure how and when you use assert, but something that stops me
> from using assert is that in many cases I would use them to
> 1) Check type of an incoming argument/returned value
> 2) Check value of an incoming argument/returned value
You use asserts to boldly state that the asserted condition never fails.
If it should fail anyway, the world could come tumbling down and you
would hang your head in shame.
Asserts help the reader of the code understand why some possibilities
are not considered by the code. They are not considered because the
writer of the code asserts they are not really possible.
Asserts help not only lay the blame to the writer of the code but might
also make it easier to troubleshoot failures.
I use asserts sparingly, just like comments (which asserts are). I use
them to communicate nonobvious truths to the future maintainer of the
code.
For example, instead of
# never reached
I will write
assert False
Or I might indicate the exhaustion of possibilities:
if status == OK:
...
elif status == ERROR:
...
else:
assert status == WARNING
...
Marko
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I love assert Peter Cacioppi <peter.cacioppi@gmail.com> - 2014-11-11 11:40 -0800
Re: I love assert Ben Finney <ben+python@benfinney.id.au> - 2014-11-12 07:03 +1100
Re: I love assert Grant Edwards <invalid@invalid.invalid> - 2014-11-11 21:43 +0000
Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-11 12:08 -0800
Re: I love assert Rob Gaddi <rgaddi@technologyhighland.invalid> - 2014-11-11 12:20 -0800
Re: I love assert Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-11-11 20:34 +0000
Re: I love assert TP <wingusr@gmail.com> - 2014-11-11 12:57 -0800
Re: I love assert Terry Reedy <tjreedy@udel.edu> - 2014-11-11 17:34 -0500
Re: I love assert Ben Finney <ben+python@benfinney.id.au> - 2014-11-12 09:52 +1100
Re: I love assert Tim Chase <python.list@tim.thechases.com> - 2014-11-11 17:03 -0600
Re: I love assert Peter Cacioppi <peter.cacioppi@gmail.com> - 2014-11-11 15:02 -0800
Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-11 15:38 -0800
Re: I love assert Dan Stromberg <drsalists@gmail.com> - 2014-11-11 17:56 -0800
Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-12 13:21 +1100
Re: I love assert Ben Finney <ben+python@benfinney.id.au> - 2014-11-12 13:35 +1100
Re: I love assert Grant Edwards <invalid@invalid.invalid> - 2014-11-12 14:10 +0000
Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-12 13:44 +1100
Re: I love assert wxjmfauth@gmail.com - 2014-11-11 23:14 -0800
Re: I love assert Terry Reedy <tjreedy@udel.edu> - 2014-11-12 03:29 -0500
Re: I love assert Anton <anton.schattenfeld@gmail.com> - 2014-11-12 12:53 -0800
Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-12 23:41 +0200
Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-12 13:52 -0800
Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-12 23:56 +0200
Re: I love assert Ian Kelly <ian.g.kelly@gmail.com> - 2014-11-12 15:04 -0700
Re: I love assert Anton <anschatten@gmail.com> - 2014-11-12 14:13 -0800
Re: I love assert Ian Kelly <ian.g.kelly@gmail.com> - 2014-11-12 15:41 -0700
Re: I love assert Anton <anschatten@gmail.com> - 2014-11-12 14:48 -0800
Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-13 01:01 +0200
Re: I love assert Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-15 10:40 +1100
Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-15 02:12 +0200
Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-15 12:04 +1100
Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-15 03:30 +0200
Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-15 12:48 +1100
Re: I love assert Tim Chase <python.list@tim.thechases.com> - 2014-11-14 20:14 -0600
Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-15 13:16 +1100
Re: I love assert albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-11-29 17:35 +0000
Re: I love assert Ian Kelly <ian.g.kelly@gmail.com> - 2014-11-12 16:02 -0700
Re: I love assert Anton <anschatten@gmail.com> - 2014-11-12 15:43 -0800
Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-13 10:10 +1100
Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-13 01:23 +0200
Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-13 10:27 +1100
Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-13 01:31 +0200
Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-12 14:47 -0800
Re: I love assert Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-14 22:37 +1100
Re: I love assert Ian Kelly <ian.g.kelly@gmail.com> - 2014-11-14 09:40 -0700
Re: I love assert Ian Kelly <ian.g.kelly@gmail.com> - 2014-11-12 15:07 -0700
Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-13 00:47 +0200
Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-12 14:56 -0800
Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-13 09:58 +1100
Re: I love assert Ian Kelly <ian.g.kelly@gmail.com> - 2014-11-12 16:05 -0700
Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-13 01:12 +0200
Re: I love assert Lie Ryan <lie.1296@gmail.com> - 2014-11-14 01:09 +1100
Re: I love assert Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-14 22:33 +1100
Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-14 10:18 -0800
Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-14 21:12 +0200
Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-14 12:41 -0800
Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-14 22:50 +0200
Re: I love assert Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-15 13:58 +1100
Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-14 20:09 -0800
Re: I love assert Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-17 13:09 +1100
Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-16 19:25 -0800
Re: I love assert Anton <anschatten@gmail.com> - 2014-11-12 14:00 -0800
Re: I love assert Anton <anschatten@gmail.com> - 2014-11-12 14:04 -0800
Re: I love assert Marko Rauhamaa <marko@pacujo.net> - 2014-11-13 00:34 +0200
Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-13 09:43 +1100
Re: I love assert Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-14 22:15 +1100
Re: I love assert Richard Riehle <rriehle@itu.edu> - 2014-11-14 14:09 -0800
Decorators (was: Re: I love assert) Marko Rauhamaa <marko@pacujo.net> - 2014-11-15 00:18 +0200
Re: Decorators Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-11-14 22:37 +0000
Re: Decorators Marko Rauhamaa <marko@pacujo.net> - 2014-11-15 00:47 +0200
Re: Decorators (was: Re: I love assert) Richard Riehle <rriehle@itu.edu> - 2014-11-14 18:19 -0800
Re: Decorators (was: Re: I love assert) Mayank Tripathi <oquanox@gmail.com> - 2014-11-15 02:36 +0000
Re: Decorators (was: Re: I love assert) Tim Chase <python.list@tim.thechases.com> - 2014-11-14 20:30 -0600
Re: Decorators Marko Rauhamaa <marko@pacujo.net> - 2014-11-15 09:00 +0200
Re: Decorators Grant Edwards <invalid@invalid.invalid> - 2014-11-15 15:32 +0000
Re: Decorators (was: Re: I love assert) Richard Riehle <rriehle@itu.edu> - 2014-11-14 23:42 -0800
Re: Decorators Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-11-15 13:12 +0000
Re: Decorators Marko Rauhamaa <marko@pacujo.net> - 2014-11-15 15:24 +0200
Re: Decorators Terry Reedy <tjreedy@udel.edu> - 2014-11-15 15:28 -0500
Re: Decorators (was: Re: I love assert) Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-16 02:39 +1100
Re: I love assert TP <wingusr@gmail.com> - 2014-11-27 01:22 -0800
Re: I love assert alister <alister.nospam.ware@ntlworld.com> - 2014-11-27 09:59 +0000
Re: I love assert Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-29 12:30 +1100
Re: I love assert MRAB <python@mrabarnett.plus.com> - 2014-11-29 02:56 +0000
Re: I love assert Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-29 20:31 +1100
Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-29 21:40 +1100
Re: I love assert MRAB <python@mrabarnett.plus.com> - 2014-11-29 19:49 +0000
Re: I love assert Chris Angelico <rosuav@gmail.com> - 2014-11-29 14:02 +1100
Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-29 14:33 -0800
Re: I love assert Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-30 19:18 +1100
Re: I love assert Ethan Furman <ethan@stoneleaf.us> - 2014-11-30 11:34 -0800
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