def amean(nums):
    """Return arithmetic mean.

    The arithmetic mean is defined as

        .. math::

            \\frac{\\sum{nums}}{|nums|}

    Cf. https://en.wikipedia.org/wiki/Arithmetic_mean

    Parameters
    ----------
    nums : list
        A series of numbers

    Returns
    -------
    float
        The arithmetric mean of nums

    Examples
    --------
    >>> amean([1, 2, 3, 4])
    2.5
    >>> amean([1, 2])
    1.5
    >>> amean([0, 5, 1000])
    335.0

    .. versionadded:: 0.1.0

    """
    return sum(nums) / len(nums)
