gistfile1.py

def interleave(*iters):
    iters = [iter(i) for i in iters]

    while True:
        stop_loop = False
        values = list()
        for i in iters:
            try:
                values.append(i.next())
            except StopIteration:
                stop_loop = True
                break

        if stop_loop:
            break

        for value in values:
            yield value

if __name__ == '__main__':
    l1 = xrange(5)
    l2 = xrange(10, 20)
    l3 = xrange(100, 300)

    print list(interleave(l1, l2, l3))