def sub_lists(my_list):
	from itertools import combinations
	
	subs = []
	for i in range(0, len(my_list)+1):
	  temp = [list(x) for x in combinations(my_list, i)]
	  if len(temp)>0:
	    subs.extend(temp)
	return subs
def heap_queue_largest(nums,n):
  import heapq as hq
  
  largest_nums = hq.nlargest(n, nums)
  return largest_nums