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

[Floris Bruynooghe]

On 28 April 2011 23:07, Guido van Rossum <guido at python.org> 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. :-)

Personaly I'd love to get rid of all of -O's meanings apart from
setting __debug__ to False.  Then you can write a strip tool which
could strip all docstrings, just unused docstrings (an improvement
over -O), and any "dead" code resulting from setting __debug__ to
either True or False.  The last thing to do is place assert statements
inside a if __debug__ block.

That way you could use the strip tool on the modules under test but
not on the test modules.

Regards
Floris

PS: I actually wrote some prototype code for such a strip tool last
year but never finished it off, so I'm pretty sure most of this is
possible.

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