140 def heappush(heap, item):  argument
142     heap.append(item)
143     _siftdown(heap, 0, len(heap)-1)
145 def heappop(heap):  argument
147     lastelt = heap.pop()    # raises appropriate IndexError if heap is empty
148     if heap:
149         returnitem = heap[0]
150         heap[0] = lastelt
151         _siftup(heap, 0)
156 def heapreplace(heap, item):  argument
167     returnitem = heap[0]    # raises appropriate IndexError if heap is empty
168     heap[0] = item
169     _siftup(heap, 0)
172 def heappushpop(heap, item):  argument
174     if heap and cmp_lt(heap[0], item):
175         item, heap[0] = heap[0], item
176         _siftup(heap, 0)
190 def _heappushpop_max(heap, item):  argument
192     if heap and cmp_lt(item, heap[0]):
193         item, heap[0] = heap[0], item
194         _siftup_max(heap, 0)
242 def _siftdown(heap, startpos, pos):  argument
243     newitem = heap[pos]
248         parent = heap[parentpos]
250             heap[pos] = parent
254     heap[pos] = newitem
295 def _siftup(heap, pos):  argument
296     endpos = len(heap)
298     newitem = heap[pos]
304         if rightpos < endpos and not cmp_lt(heap[childpos], heap[rightpos]):
307         heap[pos] = heap[childpos]
312     heap[pos] = newitem
313     _siftdown(heap, startpos, pos)
315 def _siftdown_max(heap, startpos, pos):  argument
317     newitem = heap[pos]
322         parent = heap[parentpos]
324             heap[pos] = parent
328     heap[pos] = newitem
330 def _siftup_max(heap, pos):  argument
332     endpos = len(heap)
334     newitem = heap[pos]
340         if rightpos < endpos and not cmp_lt(heap[rightpos], heap[childpos]):
343         heap[pos] = heap[childpos]
348     heap[pos] = newitem
349     _siftdown_max(heap, startpos, pos)
475     heap = []  variable
478         heappush(heap, item)
480     while heap:
481         sort.append(heappop(heap))