Testing with pytest

1# calculator.py
2def add(a, b):
3    return a + b
4
5def divide(a, b):
6    if b == 0:
7        raise ValueError("Cannot divide by zero")
8    return a / b
9
10# test_calculator.py
11import pytest
12from calculator import add, divide
13
14def test_add():
15    assert add(2, 3) == 5
16    assert add(-1, 1) == 0
17
18def test_divide():
19    assert divide(10, 2) == 5.0
20    with pytest.raises(ValueError):
21        divide(10, 0)
22
23# Run: pytest test_calculator.py -v