how to execute multiple tests on multiple items with py.test

I’m a novice in python and also in py.test. I’m searching a way to run multiple tests on multiple items and cannot find it. I’m sure it’s quite simple when you know how to do it.

I have simplified what I’m trying to do to make it simple to understand.

If I have a Test class who defines a serie of tests like this one :

class SeriesOfTests:
    def test_greater_than_30(self, itemNo):
        assert (itemNo > 30), "not greather than 30"
    def test_lesser_than_30(self, itemNo):
        assert (itemNo < 30), "not lesser thant 30"
    def test_modulo_2(self, itemNo):
        assert (itemNo % 2) == 0, "not divisible by 2"

I want to execute this SeriesOfTest on each item obtained from a function like :

def getItemNo():
    return [0,11,33]

The result i’m trying to obtain is something like :

RESULT : 
Test "itemNo = 0"
  - test_greater_than_30 = failed
  - test_lesser_than_30 = success
  - test_modulo_2 = success

Test "itemNo = 11"
  - test_greater_than_30 = failed
  - test_lesser_than_30 = success
  - test_modulo_2 = failed

Test "itemNo = 33"
  - test_greater_than_30 = success
  - test_lesser_than_30 = failed
  - test_modulo_2 = failed

How can I do this with py.test?

Than you guys (and girls also)

André

Answer

Forget about the previous answer. Given that you need the tests to be grouped by value, you can use scenarios. I’ve just adapted the example from the docs:

import pytest

def pytest_generate_tests(metafunc):
    idlist = []
    argvalues = []
    for scenario in metafunc.cls.scenarios:
        idlist.append(scenario[0])
        items = scenario[1].items()
        argnames = [x[0] for x in items]
        argvalues.append(([x[1] for x in items]))
    metafunc.parametrize(argnames, argvalues, ids=idlist, scope="class")

scenario1 = ('itemNo = 0', {'itemNo': 0})
scenario2 = ('itemNo = 11', {'itemNo': 11})
scenario3 = ('itemNo = 33', {'itemNo': 33})

class TestSeries:
    scenarios = [scenario1, scenario2, scenario3]
    
    def test_greater_than_30(self, itemNo):
        assert (itemNo > 30), "not greather than 30"
    def test_lesser_than_30(self, itemNo):
        assert (itemNo < 30), "not lesser thant 30"
    def test_modulo_2(self, itemNo):
        assert (itemNo % 2) == 0, "not divisible by 2"

And the output is:

$ py.test -v
============ test session starts ==============================================
platform linux2 -- Python 2.7.4 -- pytest-2.4.2 -- /home/jose/.virtualenvs/pytest1/bin/python
collected 9 items 

test_first.py:23: TestSeries.test_greater_than_30[itemNo = 0] FAILED
test_first.py:25: TestSeries.test_lesser_than_30[itemNo = 0] PASSED
test_first.py:27: TestSeries.test_modulo_2[itemNo = 0] PASSED
test_first.py:23: TestSeries.test_greater_than_30[itemNo = 11] FAILED
test_first.py:25: TestSeries.test_lesser_than_30[itemNo = 11] PASSED
test_first.py:27: TestSeries.test_modulo_2[itemNo = 11] FAILED
test_first.py:23: TestSeries.test_greater_than_30[itemNo = 33] PASSED
test_first.py:25: TestSeries.test_lesser_than_30[itemNo = 33] FAILED
test_first.py:27: TestSeries.test_modulo_2[itemNo = 33] FAILED

I think that’s the closest you can get.