def windumrechner(wind):
    """
    Umwandlung von milen pro std in km/h
    :param wind: Int, float or None
    :return: Float or None
    """
    if isinstance(wind, (int, float)):
        kmh = wind * 1.609346
        kmh = round(kmh, 2)
        return kmh
    else:
        return None