Python 如何合并中间的两台发电机？

我如何合并两个不同的生成器，在每次迭代中，一个不同的生成器将获得收益

>>> gen = merge_generators_in_between("ABCD","12")
>>> for val in gen:
...     print val
A
1
B
2
C
D

我怎样才能做到这一点？我在中找不到它的函数。

查看下面的循环：

看看下面的循环赛：

>>> from itertools import cycle, islice
>>> def roundrobin(*iterables):
        "roundrobin('ABC', 'D', 'EF') --> A D E B F C"
        # Recipe credited to George Sakkis
        pending = len(iterables)
        nexts = cycle(iter(it).next for it in iterables)
        while pending:
            try:
                for next in nexts:
                    yield next()
            except StopIteration:
                pending -= 1
                nexts = cycle(islice(nexts, pending))


>>> for x in roundrobin("ABCD", "12"):
        print x


A
1
B
2
C
D