A generic priority queue for Python

When using a priority queue, decrease-key is a must-have operation for many algorithms (Dijkstra's Algorithm, A*, OPTICS), I wonder why Python's built-in priority queue does not support it. None of the other answers supply a solution that supports this functionality.

A priority queue which also supports decrease-key operation is this implementation by Daniel Stutzbach worked perfectly for me with Python 3.5.

from heapdict import heapdict

hd = heapdict()
hd["two"] = 2
hd["one"] = 1
obj = hd.popitem()
print("object:",obj[0])
print("priority:",obj[1])

# object: one
# priority: 1

You can use Queue.PriorityQueue.

Recall that Python isn't strongly typed, so you can save anything you like: just make a tuple of (priority, thing) and you're set.