Apr 8, 2013 python

Table of Contents

Python has many testing frameworks including its venerable unittest as well as alternatives.

Nose

Nose is an easier-to-use unittest.

Simple example:

from nose.tools import *
import NAME

def setup():
    print "SETUP!"

def teardown():
    print "TEAR DOWN!"

def test_basic():
    print "I RAN!"

Run test

$ nosetests

Test files go in tests/ directory and named SOMETHING_tests.py in order to run. If not, it won’t run.

Example from http://learnpythonthehardway.org/book/ex47.html

from nose.tools import *
from ex47.game import Room

def test_room():
    gold = Room("GoldRoom",
                """This room has gold in it you can grab. There's a
                door to the north.""")
    assert_equal(gold.name, "GoldRoom")
    assert_equal(gold.paths, {})

def test_room_paths():
    center = Room("Center", "Test room in the center.")
    north = Room("North", "Test room in the north.")
    south = Room("South", "Test room in the south.")

    center.add_paths({'north': north, 'south': south})
    assert_equal(center.go('north'), north)
    assert_equal(center.go('south'), south)

def test_map():
    start = Room("Start", "You can go west and down a hole.")
    west = Room("Trees", "There are trees here, you can go east.")
    down = Room("Dungeon", "It's dark down here, you can go up.")

    start.add_paths({'west': west, 'down': down})
    west.add_paths({'east': start})
    down.add_paths({'up': start})

    assert_equal(start.go('west'), west)
    assert_equal(start.go('west').go('east'), start)
    assert_equal(start.go('down').go('up'), start)

Nose2

test-generator

Generator is a helper for generating test methods for nose while still using unittest. It supports both nose and unnittest2.

Example code

# from https://justin.abrah.ms/python/test_generators.html
# test generator (better)
class TestRound(object):
    def _check_rounding(self, test, expected):
        assert round(test) == expected

    def test_rounding(self):
        for x, y in [(1, 1),
                    (1.9, 2)]:
            yield self._check_rounding, x, y

# unittest (old way)
class TestRound(unittest.TestCase):
    def test_rounding_same(self):
        self.assertEquals(round(1), 1)

    def test_rounding_one_dot_nine_to_two(self):
        self.assertEquals(round(1.9), 2)