cron.py 文件源码

def _merge(sorted_iterables):
    """
    >>> list(_merge([(1, 2, 3), (0, 2, 4)]))
    [0, 1, 2, 2, 3, 4]
    """

    heap = []

    for iterable in sorted_iterables:
        iterator = iter(iterable)

        for value in iterator:
            heapq.heappush(heap, (value, iterator))
            break

    while heap:
        value, iterator = heapq.heappop(heap)

        yield value

        for value in iterator:
            heapq.heappush(heap, (value, iterator))
            break