python 中最大，最小数的问题

import heapq
nums = [1,8,9,2,4,3]
print heapq.nlargest(3, nums)
#[9,8,4]
print heapq.nsmallest(3, nums)
#[1,2,4]

list_demo = [{'a':1,'b':'a'},....]
heapq.nlargest(1,list_demo,key=lambda s:s['a'])

print min(nums)
print max(nums)

print sorted(nums)