heap.py

import heapq

# heap = [5,4,6,10,2]
# heapq.heapify(heap) 
# heapq.heappush(heap, 20)
# min_elem = heapq.heappop(heap)

def klargest(lst, k):
  lst = [-x for x in lst]
  heapq.heapify(lst) # O(n)

  result = None
  for i in range(k):
    result = heapq.heappop(lst)

  return result

print(-1 * klargest([5,4,6,10,2], 2))