In section 3.4, in the exercise Exercise: Refactoring To Use a Pure Function, it asks you to write a function:

def compute_standard_deviation_by_day(data):
    # TODO
    return daily_standard_deviation

In the solution to the next exercise, it tries to import this incorrectly, meaning the test breaks when you try to run it:

def test_compute_standard_deviation_by_day(data, expected_output):
    from inflammation.compute_data import compute_standard_deviation_by_data

Should be consistent between compute_standard_deviation_by_day or compute_standard_deviation_by_data