我有以下两个清单:
nums = [1, 2, 3, 4, 5, 6, 7, 8]
ltrs = ['a', 'b', 'c', 'd']
for x, y in nums, ltrs:
print(x, y)
出现以下错误
c:\Python35\Scripts>python listtest.py
Traceback (most recent call last):
File "listtest.py", line 5, in <module>
for x, y in nums, ltrs:
ValueError: too many values to unpack (expected 2)
我希望输出为:
1a,2b,3c,4d,5,6,7,8
根据我的阅读,zip
方法只有在两个列表的长度相同时才有效,对于不同长度的列表,我有哪些选择?
答案 0 :(得分:4)
izip_longest
与zip
类似,但允许您添加默认值(fillvalue
)以在较短列表用尽时使用。从那以后,它只是一些简单的操作:
[''.join([str(c) for c in x]) for x in izip_longest(nums, ltrs, fillvalue='')]
答案 1 :(得分:4)
您可以将itertools.zip_longest
用于Python3:
import itertools
nums = [1, 2, 3, 4, 5, 6, 7, 8]
ltrs = ['a', 'b', 'c', 'd']
final_list = [''.join([str(c) if isinstance(c, int) else c for c in [i for i in b if i is not None]]) for b in itertools.zip_longest(nums, ltrs)]
输出:
['1a', '2b', '3c', '4d', '5', '6', '7', '8']
答案 2 :(得分:2)
import itertools
for x, y in list(itertools.zip_longest(nums,ltrs)):
print(x, y)
输出
1 a
2 b
3 c
4 d
5 None
6 None
7 None
8 None