Differences

This shows you the differences between two versions of the page.

--- stacks_queues [2020/01/12 05:18] – created jrseti
+++ stacks_queues [2020/01/14 02:16] (current) – jrseti
@@ Line 2: / Line 2: @@
+====heapqueue====
+https://docs.python.org/2/library/heapq.html
+  heapq.heappush(heap, item)
+  Push the value item onto the heap, maintaining the heap invariant.
+  heapq.heappop(heap)
+  Pop and return the smallest item from the heap, maintaining the heap invariant. If the heap is empty, IndexError
+  is raised. To access the smallest item without popping it, use heap[0].
+  heapq.heappushpop(heap, item)
+  Push item on the heap, then pop and return the smallest item from the heap. The
+  combined action runs more efficiently than heappush() followed by a separate call
+  to heappop().
+  heapq.heapify(x)
+  Transform list x into a heap, in-place, in linear time.
+  heapq.heapreplace(heap, item)
+  Pop and return the smallest item from the heap, and also push the new item. The
+  heap size doesn’t change. If the heap is empty, IndexError is raised.
+  This one step operation is more efficient than a heappop() followed by heappush()
+  and can be more appropriate when using a fixed-size heap. The pop/push combination
+  always returns an element from the heap and replaces it
+  with item.
+  The value returned may be larger than the item added. If that isn’t desired,
+  consider using heappushpop() instead. Its push/pop combination returns the smaller
+  of the two values, leaving the larger value on the heap.
+  The module also offers three general purpose functions based on heaps.
+  heapq.merge(*iterables)
+  Merge multiple sorted inputs into a single sorted output (for example, merge
+  timestamped entries from multiple log files). Returns an iterator over the sorted values.
+  Similar to sorted(itertools.chain(*iterables)) but returns an iterable, does not pull
+  the data into memory all at once, and assumes that each of the input streams is already
+  sorted (smallest to largest).
+  heapq.nlargest(n, iterable[, key])
+  Return a list with the n largest elements from the dataset defined by iterable. key,
+  if provided, specifies a function of one argument that is used to extract a comparison
+  key from each element in the iterable: key=str.lower Equivalent to:
+    sorted(iterable, key=key, reverse=True)[:n]
+  heapq.nsmallest(n, iterable[, key])
+  Return a list with the n smallest elements from the dataset defined by iterable. key,
+  if provided, specifies a function of one argument that is used to extract a comparison
+  key from each element in the iterable: key=str.lower
+    Equivalent to: sorted(iterable, key=key)[:n]