Python 以特定方式追加列表

Question

我知道我实际上可以按如下方式合并两个列表(在 Python 2.7 中)

list1 = ['one', 'two', 'three', 'four', 'five']
list2 = ['A', 'B', 'C', 'D', 'E']
merged = list1 + list2
print merged
# ['one', 'two', 'three', 'four', 'five', 'A', 'B', 'C', 'D', 'E']

问题是，我想在每两个 list1 之后插入一个 list2。示例:

list1 = ['one', 'two', 'three', 'four', 'five']
list2 = ['A', 'B', 'C', 'D', 'E']
after 2 of list1:
     add 1 of list2
print merged
# ['one', 'two', 'A', 'three', 'four', 'B', 'five', 'six', 'C', 'seven', 'eight', 'D', 'nine', 'ten']

非常感谢任何帮助!

Answer 1

在这种情况下，使用原始迭代器可以生成干净的代码，您可以在迭代器上调用 next 来获取下一个值，然后将其追加到结果中，这样列表的创建就是非常直观:

list1 = ['one', 'two', 'three', 'four', 'five']
list2 = ['A', 'B', 'C', 'D', 'E']
iter_list1 = iter(list1)
iter_list2 = iter(list2)

final = []
try: #broken when one of the iterators runs out (and StopIteration is raised)
    while True:
        final.append(next(iter_list1))
        final.append(next(iter_list1))

        final.append(next(iter_list2))
except StopIteration:
    pass
#one will already be empty, add the remaining elements of the non-empty one to the end of the list.
final.extend(iter_list1)
final.extend(iter_list2)

print(final)