Question

我有2个名单：

x = ['a','b','c']
y = ['d','e','f']

我需要一个列表清单：

z = [['a','d'],['b','e'],['c','f']]

我尝试了什么：

# Concatenate x and y with a space
w = []
for i in range(len(x)):
    w.append(x[i]+" "+y[i])

# Split each concatenated element into a sublist
z = []
for i in range(len(w)):
    z.append(w[i].split())

有没有办法在不使用2 for循环的情况下直接执行此操作？（我对Python很新）

Answer 1

如果列表很大，您可以使用zip（itertools.izip）：

>>> x = ['a','b','c']
>>> y = ['d','e','f']
>>> zip(x, y)
[('a', 'd'), ('b', 'e'), ('c', 'f')]
>>> map(list, zip(x, y))  # If you need lists instead of tuples
[['a', 'd'], ['b', 'e'], ['c', 'f']]
>>>

Answer 2

如果两个长度相同，则使用enumerate：

[[a,y[ind]] for ind, a in enumerate(x)]

它比zip更有效。

In [6]: %timeit [[a,y[ind]] for ind,a in enumerate(x)]
1000000 loops, best of 3: 970 ns per loop

In [7]: %timeit map(list, zip(x, y))
1000000 loops, best of 3: 1.48 µs per loop

将2个列表转换为列表列表

2 个答案: