获取列表列表中嵌套变量的总平均值

def get_average_nested_variable(nested_list):
    total_sum = 0
    count = 0

    for sublist in nested_list:
        for variable in sublist:
            if isinstance(variable, (int, float)):
                total_sum += variable
                count += 1

    if count > 0:
        average = total_sum / count
        return average
    else:
        return None