python sort() sorted()

list.sort() 不会返回对象，会改变原有的list ，默认地按升序排列，sort()只适应于列表

L =[34,22,56,18,90,30,21]print(L.sort())print(L)输出None[18, 21, 22, 30, 34, 56, 90]

sort()函数原型: 

L.sort(key=None, reverse=False)

reverse : 是否颠倒排列顺序,默认False

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sorted()   适应可迭代的对象  返回副本，原始输入不变

sorted(iterable,key=None, reverse=False) 

iterable：可迭代的对象

key：排序需要比较的值

reverse ：是否颠倒排列顺序,默认False

根据成绩来排名：

L =[("Joe","Math990112",89),("Mike","CS991301",100),("Mary","EE990830",95)]L1= sorted(L,key=lambda score:score[2])print(L)print(L1)输出：[('Joe', 'Math990112', 89), ('Mike', 'CS991301', 100), ('Mary', 'EE990830', 95)][('Joe', 'Math990112', 89), ('Mary', 'EE990830', 95), ('Mike', 'CS991301', 100)]