Common Assert Methods

self.assertEqual(a, b)
self.assertNotEqual(a, b)
self.assertTrue(expression)
self.assertFalse(expression)
self.assertIn(item, collection)
self.assertRaises(ExceptionType, function, argument)

class EqualityTests(TestCase):
    def test_addition(self):
        self.assertEqual(1 + 1, 2)

    def test_not_equal(self):
        self.assertNotEqual(1 + 1, 3)

class BooleanTests(TestCase):
    def test_is_active_true(self):
        self.assertTrue(1 > 0)

    def test_is_active_false(self):
        self.assertFalse(1 < 0)

class OtherAssertTests(TestCase):
    def test_value_in_list(self):
        self.assertIn(3, [1, 2, 3])

    def test_division_by_zero_raises(self):
        with self.assertRaises(ZeroDivisionError):
            1 / 0

Common Model Field Types · Test Database Behavior · Running Tests with manage.py · The Django Test Client

1. Using assertTrue(a == b) instead of assertEqual(a, b) — it works, but produces a far less useful failure message.
2. Comparing floating point numbers with assertEqual instead of assertAlmostEqual, causing flaky failures from rounding.
3. Forgetting that assertRaises must wrap the call inside a with block, not just check a return value.

• assertEqual(a, b) and assertNotEqual(a, b) compare two values.
• assertTrue(x) and assertFalse(x) check a single boolean condition.
• assertIn(item, container) checks membership, and assertRaises checks that an exception is raised.
• Picking the most specific assert method gives the clearest failure message when a test breaks.