heapq 的nlargest 和 nsmallest

【popexizhi:
heapq 的nlargest 和 nsmallest 这个好用啊，可以支持key，这个之前统计自己还重写过一个，嘻嘻，mark 。py2/py3都支持啊！
】

>>> import heapq
>>> nums = [1,2,3,4,5,6,7,8,9]
>>> heapq.nlargest(2, nums)
[9, 8]
>>> heapq.nsmallest(2, nums)
[1, 2]



>>> portfo = [{"name": "IBM", "p":"12.5"}, ]
KeyboardInterrupt
>>> portfo = [{"name": "IBM", "p":"12.5"},{"name": "I", "p":"12.51"},{"name": "IB", "p":"12.153"}]
>>> heapq.nsmallest(2, portfo, key=lambda s: s['p'])
[{'name': 'IB', 'p': '12.153'}, {'name': 'IBM', 'p': '12.5'}]
>>> heapq.nlargest(2, portfo, key=lambda s: s['p'])
[{'name': 'I', 'p': '12.51'}, {'name': 'IBM', 'p': '12.5'}]