Using docstrings for testing

Good Python includes docstrings inside every module, class, function, and method. Many tools can create useful, informative documentation from docstrings. Here's an example of a function-level docstring, from the Writing clear documentation strings with RST markup recipe in Chapter 3, Function Definitions:

def Twc(T: float, V: float) -> float:
    """Computes the wind chill temperature
    The wind-chill, :math:'T_{wc}', is based on
    air temperature, T, and wind speed, V.
    :param T: Temperature in °C
    :param V: Wind Speed in kph
    :returns: Wind-Chill temperature in °C
    :raises ValueError: for low wind speeds or high Temps
    """
    if V < 4.8 or T > 10.0:
        raise ValueError(
            "V must be over 4.8 kph, T must be below 10°C")
    return (
         13.12 + 0.6215 * T 
         - 11.37 * V ** 0.16 + 0.3965 * T * V ** 0.16
    )

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