如何在2D列表中拆分字符串？

# 示例的2D列表
list_2d = [['Hello World'], ['Welcome to Cloud Computing'], ['This is a test']]

# 遍历2D列表中的每个元素
for i in range(len(list_2d)):
    for j in range(len(list_2d[i])):
        # 使用split()方法拆分字符串
        split_str = list_2d[i][j].split(' ')

        # 替换原来的字符串
        list_2d[i][j] = split_str

# 输出拆分后的2D列表
print(list_2d)

[[['Hello', 'World']], [['Welcome', 'to', 'Cloud', 'Computing']], [['This', 'is', 'a', 'test']]]