130 def heappush(heap, item):  argument
132     heap.append(item)
133     _siftdown(heap, 0, len(heap)-1)
135 def heappop(heap):  argument
137     lastelt = heap.pop()    # raises appropriate IndexError if heap is empty
138     if heap:
139         returnitem = heap[0]
140         heap[0] = lastelt
141         _siftup(heap, 0)
145 def heapreplace(heap, item):  argument
156     returnitem = heap[0]    # raises appropriate IndexError if heap is empty
157     heap[0] = item
158     _siftup(heap, 0)
161 def heappushpop(heap, item):  argument
163     if heap and heap[0] < item:
164         item, heap[0] = heap[0], item
165         _siftup(heap, 0)
179 def _heappop_max(heap):  argument
181     lastelt = heap.pop()    # raises appropriate IndexError if heap is empty
182     if heap:
183         returnitem = heap[0]
184         heap[0] = lastelt
185         _siftup_max(heap, 0)
189 def _heapreplace_max(heap, item):  argument
191     returnitem = heap[0]    # raises appropriate IndexError if heap is empty
192     heap[0] = item
193     _siftup_max(heap, 0)
205 def _siftdown(heap, startpos, pos):  argument
206     newitem = heap[pos]
211         parent = heap[parentpos]
213             heap[pos] = parent
217     heap[pos] = newitem
258 def _siftup(heap, pos):  argument
259     endpos = len(heap)
261     newitem = heap[pos]
267         if rightpos < endpos and not heap[childpos] < heap[rightpos]:
270         heap[pos] = heap[childpos]
275     heap[pos] = newitem
276     _siftdown(heap, startpos, pos)
278 def _siftdown_max(heap, startpos, pos):  argument
280     newitem = heap[pos]
285         parent = heap[parentpos]
287             heap[pos] = parent
291     heap[pos] = newitem
293 def _siftup_max(heap, pos):  argument
295     endpos = len(heap)
297     newitem = heap[pos]
303         if rightpos < endpos and not heap[rightpos] < heap[childpos]:
306         heap[pos] = heap[childpos]
311     heap[pos] = newitem
312     _siftdown_max(heap, startpos, pos)