PriorityQueue by default, only support minheaps.

One way to implement max_heaps with it, could be,

# Max Heap
class MaxHeapElement(object):

    def __init__(self, x):
        self.x = x

    def __lt__(self, other):
        return self.x > other.x

    def __str__(self):
        return str(self.x)


max_heap = PriorityQueue()

max_heap.put(MaxHeapElement(10))
max_heap.put(MaxHeapElement(20))
max_heap.put(MaxHeapElement(15))
max_heap.put(MaxHeapElement(12))
max_heap.put(MaxHeapElement(27))

while not max_heap.empty():
    print(max_heap.get())

Yes, it is possible.

Let's say you have a list:

k = [3,2,6,4,9]

Now, let's say you want to print out the max element first(or any other element with the maximum priority). Then the logic is to reverse the priority by multiplying it with -1, then use the PriorityQueue class object which supports the min priority queue for making it a max priority queue.

For example:

k = [3,2,6,4,9]
q = PriorityQueue()
for idx in range(len(k)):
    # We are putting a tuple to queue - (priority, value)
    q.put((-1*k[idx], idx))

# To print the max priority element, just call the get()
# get() will return tuple, so you need to extract the 2nd element
print(q.get()[1]

NB: Library is queue.PriorityQueue in Python3

Based on the comments, the simplest way to get maxHeap is to insert negative of the element.

max_heap = PriorityQueue()

max_heap.put(MaxHeapElement(-10))
max_heap.put(MaxHeapElement(-20))
max_heap.put(MaxHeapElement(-15))
max_heap.put(MaxHeapElement(-12))
max_heap.put(MaxHeapElement(-27))

while not max_heap.empty():
    print(-1*max_heap.get())

Invert the value of the keys and use heapq. For example, turn 1000.0 into -1000.0 and 5.0 into -5.0.

from heapq import heappop, heappush, heapify

heap = []
heapify(heap)

heappush(heap, -1 * 1000)
heappush(heap, -1 * 5)
-heappop(heap) # return 1000
-heappop(heap) # return 5