I agree that such hints about the tests would be nice for performance, but i don't think considerations about performance were ever given a high priority during the design of Python.
How about this:
def sum(): # implementation @sum.test def test_sum(): assert sum() == 0
This potentially could do the same things you expected from the where-statement, without introducing new keywords. Maybe this could also be buried into some stdlib module in order to avoid "polluting" the core language if this way of writing tests doesn't gain any traction.
import unittest # or whatever def sum(): # implementation @unittest.test_func(sum): def test_sum(): assert sum() == 0
On 2013-11-10 11:06, Tarek Ziadé wrote:
Le 11/10/13 11:00 AM, Markus Unterwaditzer a écrit :
While it is a nice idea, i don't think this feature deserves its own syntax. Besides doctests, another way of achieving this in Python might be:
# implementation of sum
def test_sum(): assert sum() == 0 assert sum([1, 2, 3]) == 6
which IMO is nice enough. yes, that's what we all already do: tests in test_xxx functions. And the adopted convention is to have the tests in dedicated tests modules, which defeats the benefit of having real isolated unit tests just by the function code.
And even if we place the test function just besides the tested function, Python will not make any distinction : they are both just functions.
Having the ability to distinguish tests and regular code at the language level has benefits like the ability to ignore tests when you run the app in production etc.
"Tarek Ziadé" firstname.lastname@example.org wrote:
I've read about Pyret on hackernews: http://www.pyret.org/ 
and found the 'where' statement very compeling. Functions can end with a where that contains small unit tests.
From the documentation example:
fun sum(l): cases(List) l: | empty => 0 | link(first, rest) => first + sum(rest) end where: sum() is 0 sum([1, 2, 3]) is 6 end It's quite similar to the doctests ideas I guess - but not intended to be documentation like them.
I ended up disliking docttests because of this doc+test duality by the way: it often ends up as a not so good documentation and not so good tests.
Anyways, having a dedicated keyword to append after a function some tests as part of the language has benefits imho:
Python-ideas mailing list Pythonemail@example.com https://mail.python.org/mailman/listinfo/python-ideas