有没有一种方法可以得到包含许多列表的列表中值的算术平均值？

def calculate_average(lists):
    flattened_list = [value for sublist in lists for value in sublist]
    total_sum = sum(flattened_list)
    num_values = len(flattened_list)
    average = total_sum / num_values
    return average

# 示例用法
lists = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
result = calculate_average(lists)
print("算术平均值:", result)