[Python][library] simple heapq implementation

heapqueue.py

# heap queue simple implementation

def heappush(heap, val):
    cur = len(heap)
    heap.append(val)
    while cur > 0:
        parent = (cur - 1) // 2
        if heap[parent] <= heap[cur]: break
        heap[cur], heap[parent] = heap[parent], heap[cur]
        cur = parent
        pass
    pass

def heappop(heap):
    ret = heap[0]
    last = heap.pop()
    size = len(heap)
    if size == 0: return ret
    heap[0] = last
    cur = 0
    while True:
        ch1 = 2 * cur + 1
        if ch1 >= size: return ret
        ch2 = ch1 + 1
        child = ch2 if ch2 < size and heap[ch2] < heap[ch1] else ch1
        if heap[cur] <= heap[child]: return ret
        heap[child], heap[cur] = heap[cur], heap[child]
        cur = child
        pass
    pass

if __name__ == "__main__":
    heap = []
    heappush(heap, 4)
    heappush(heap, 10)
    heappush(heap, 1)
    heappush(heap, 100)
    heappush(heap, 0)
    heappush(heap, 20)

    while heap: print heappop(heap)
    pass