Python中的列表操作 - 增加元素列表

Question

我定义:

A = [[1, 2], [3, 4], [5, 6]]

生产线是什么？

B = [['hello', [1, 2]], ['hello', [3, 4]], ['hello', [5, 6]]]

Answer 1

您可以'hello'使用列表推导添加到每个列表的前面:

>>> add = 'hello'
>>> A = [[1, 2], [3, 4], [5, 6]]
>>> [[add, x] for x in A]
[['hello', [1, 2]], ['hello', [3, 4]], ['hello', [5, 6]]]
# or [[add] + [x] for x in A]