Track 13 · Lesson 4 of 12

Testing exceptions and floats

Check that code raises the right exception with pytest.raises, and compare floating-point results safely with pytest.approx.

You will be able to

• Test that a function raises a specific exception with pytest.raises
• Check the exception's message with match= or excinfo.value
• Explain why == is unreliable for floats and use pytest.approx instead
• Choose between rounding, approx with rel or abs, and exact comparison