python3部分小技巧

1、多元素排序

aa = [[1,2,3],[6,7,4],[6,6,3]]
sorted(aa,key = lambda x:(x[0],x[1]),reverse = False) 

输出：[[1, 2, 3], [6, 6, 3], [6, 7, 4]]

2、日期

stTime = '2017-03-01 13:21:22'
edTime = '2018-04-04 16:56:22'
st=datetime.datetime.strptime(stTime, "%Y-%m-%d %H:%M:%S")
ed=datetime.datetime.strptime(edTime, "%Y-%m-%d %H:%M:%S")
rtn = ed -st

3、合并两个字典

比如：l1=[1,2,3]
           l2=['baidu','google','bing']
py3.x中
dict(map(lambda x,y:[x,y], l1,l2))
{1:'baidu', 2:'google', 3:'bing'}
py2.x中
dict(zip(l1,l2))

4、如何判断为空、假

False,0,'',[],{},()都可以视为假