def my_sum(list_of_nums: list) -> float:
    """Returns the sum of numbers from list_of_nums.
    Stop if non-number is trying to be processed.

    >>> my_sum([2.0, -5, 'q', 3.14])
    -3.0
    """
    result = 0.0
    try:
        for num in list_of_nums:
            result += float(num)
    finally:
        return result