Assertion tools

In this section, we collect the most important tools for raising an AssertionError. We saw the assert command and two tools from unittest, namely assertAlmostEqual. The following table (Table 13.1) summarizes the most important assertion tools and the related modules:

Assertion tool and application example	Module
assert 5==5	–
assertEqual(5.27, 5.27)	unittest.TestCase
assertAlmostEqual(5.24, 5.2,places = 1)	unittest.TestCase
assertTrue(5 > 2)	unittest.TestCase
assertFalse(2 < 5)	unittest.TestCase
assertRaises(ZeroDivisionError,lambda x: 1/x,0.)	unittest.TestCase
assertIn(3,{3,4})	unittest.TestCase
assert_array_equal(A,B)	numpy.testing
assert_array_almost_equal(A, B, decimal=5)	numpy.testing
assert_allclose(A, B, rtol=1.e-3,atol=1.e-5)	numpy.testing

Table 13.1: Assertion tools in Python, unittest and NumPy