python - 在不破坏 python 结构的情况下修改 "list of lists of tuples"结构中的内容

Question

这听起来像是一个简单的问题。但是，给定一个:

a = [[(1,2)], [(3,4), (5,6)], [(7,8), (9,10), (11,12)]]

如何为元组中的第一项添加 1，以便得到后续项？

b = [[(2,2)], [(4,4), (6,6), [(8,8), (10,10), (12,12)]]

我试了一段代码如下:

b = []

for list_of_tuples in a:
    for num1, num2 in list_of_tuples:
        b.append((num1+1, num2))

b

但是，这会破坏原来的结构。那么，如何使用两个 for 循环获得我想要的结果？

Answer 1

使用嵌套列表理解:

>>> a = [[(1,2)], [(3,4), (5,6)], [(7,8), (9,10), (11,12)]]
>>> b = [[(x+1, y) for x, y in tuples] for tuples in a]
>>> b
[[(2, 2)], [(4, 4), (6, 6)], [(8, 8), (10, 10), (12, 12)]]

作为具有列表理解的for:

b = []
for tuples in a:
    b.append([(x+1, y) for x, y in tuples])

没有任何列表理解:

b = []
for tuples in a:
    tuples_b = []
    for x, y in tuples:
        tuples_b.append((x+1, y))
    b.append(tuples_b)