from __future__ import annotations


def find_max(nums: list[int | float]) -> int | float:
    """
    >>> for nums in ([3, 2, 1], [-3, -2, -1], [3, -3, 0], [3.0, 3.1, 2.9]):
    ...     find_max(nums) == max(nums)
    True
    True
    True
    True
    >>> find_max([2, 4, 9, 7, 19, 94, 5])
    94
    >>> find_max([])
    Traceback (most recent call last):
        ...
    ValueError: find_max() arg is an empty sequence
    """
    if len(nums) == 0:
        raise ValueError("find_max() arg is an empty sequence")
    max_num = nums[0]
    for x in nums:
        if x > max_num:
            max_num = x
    return max_num


if __name__ == "__main__":
    import doctest

    doctest.testmod(verbose=True)