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Using assertEqual and Other Assertions

Common assertions

Equality

assert_equal.py
self.assertEqual(actual, expected)
self.assertNotEqual(actual, expected)
assert_equal.py
self.assertEqual(actual, expected)
self.assertNotEqual(actual, expected)

Truthiness

assert_truthy.py
self.assertTrue(condition)
self.assertFalse(condition)
assert_truthy.py
self.assertTrue(condition)
self.assertFalse(condition)

None checks

assert_none.py
self.assertIsNone(value)
self.assertIsNotNone(value)
assert_none.py
self.assertIsNone(value)
self.assertIsNotNone(value)

Identity / type

assert_type.py
self.assertIs(a, b)
self.assertIsInstance(obj, dict)
assert_type.py
self.assertIs(a, b)
self.assertIsInstance(obj, dict)

Testing exceptions

Use assertRaisesassertRaises for exception behavior.

assert_raises.py
import unittest
 
 
def parse_age(s: str) -> int:
    age = int(s)
    if age < 0:
        raise ValueError("age must be >= 0")
    return age
 
 
class TestParseAge(unittest.TestCase):
    def test_negative_age_raises(self):
        with self.assertRaises(ValueError):
            parse_age("-1")
assert_raises.py
import unittest
 
 
def parse_age(s: str) -> int:
    age = int(s)
    if age < 0:
        raise ValueError("age must be >= 0")
    return age
 
 
class TestParseAge(unittest.TestCase):
    def test_negative_age_raises(self):
        with self.assertRaises(ValueError):
            parse_age("-1")

Tip

Prefer specific assertions (e.g., assertIsNoneassertIsNone) instead of assertTrue(x is None)assertTrue(x is None).

🧪 Try It Yourself

Exercise 1 – Write a unittest TestCase

Exercise 2 – assertRaises

Exercise 3 – setUp and tearDown

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