[Python-Dev] the role of assert in the standard library ?

[Raymond Hettinger]

On Apr 28, 2011, at 3:07 PM, Guido van Rossum wrote:

> On Thu, Apr 28, 2011 at 2:53 PM, Raymond Hettinger
> <raymond.hettinger at gmail.com> wrote:
>> 
>> On Apr 28, 2011, at 1:27 PM, Holger Krekel wrote:
>> 
>>> On Thu, Apr 28, 2011 at 6:59 PM, Guido van Rossum <guido at python.org> wrote:
>>>> On Thu, Apr 28, 2011 at 12:54 AM, Tarek Ziadé <ziade.tarek at gmail.com> wrote:
>>>>> In my opinion assert should be avoided completely anywhere else than
>>>>> in the tests. If this is a wrong statement, please let me know why :)
>>>> 
>>>> I would turn that around. The assert statement should not be used in
>>>> unit tests; unit tests should use self.assertXyzzy() always.
>>> 
>>> FWIW this is only true for the unittest module/pkg policy for writing and
>>> organising tests. There are other popular test frameworks like nose and pytest
>>> which promote using plain asserts within writing unit tests and also allow to
>>> write tests in functions.  And judging from my tutorials and others places many
>>> people appreciate the ease of using asserts as compared to learning tons
>>> of new methods. YMMV.
>> 
>> I've also observed that people appreciate using asserts with nose.py and py.test.
> 
> They must not appreciate -O. :-)

It might be nice if there were a pragma or module variable to selectively enable asserts for a given test module so that -O would turn-off asserts in the production code but leave them on in a test_suite.

Raymond