pytest Tests

from src.shapes.Square import Square

class TestSquare:
    
    def test_square_constructor_should_set_length(self):
        square = Square(2.0)
        assert square.length == 2.0

pytest Parameterized Tests

from src.shapes.Square import Square
import pytest

class TestSquare:
 
    @pytest.mark.parametrize("value", [1.0, 2.1, 3.2, 4.3, 5.9])
    def test_set_length_to_positive_value(self, value):
        square = Square(value)
        assert square.length == value

pytest Assertions

• assert <boolean expression>
• assert actual == pytest.approx(expected)
• assert actual is expected
• assert actual is None

Catching Exceptions

def test_zero_division():
    with pytest.raises(ZeroDivisionError):
        calculator.divide(1, 0)

Checking Output

from pytest import CaptureFixture
from _pytest.capture import CaptureResult
from typing import Any
from src.hello.HelloWorld import HelloWorld

def test_hello_world(self, capsys: CaptureFixture[Any]) -> None:
    HelloWorld.main(["HelloWorld"])
    captured: CaptureResult[Any] = capsys.readouterr()
    assert captured.out == "Hello World\n", "Unexpected Output"