Python Testing with pytest

Using assert Statements

When you write test functions, the normal Python assert statement is your primary tool to communicate test failure. The simplicity of this within pytest is brilliant. It’s what drives a lot of developers to use pytest over other frameworks.

If you’ve used any other testing framework, you’ve probably seen various assert helper functions. For example, following is a list of a few of the assert forms and assert helper functions from unittest:

pytest	unittest
assert something	assertTrue(something)
assert not something	assertFalse(something)
assert a == b	assertEqual(a, b)
assert a != b	assertNotEqual(a, b)
assert a is None	assertIsNone(a)
assert a is not None	assertIsNotNone(a)
assert a <= b	assertLessEqual(a, b)
…	…

With pytest, you can ...