aa={"aaa":3,"bbb":2,"ccc":1,"ddd":5} bb= sorted(aa.items(), key = lambda a:a[1],reverse=True) 输出 {'aaa': 3, 'bbb': 2, 'ccc': 1, 'ddd': 5} [('ddd', 5), ('aaa', 3), ('bbb', 2), ('ccc', 1)]
reverse=False {'aaa': 3, 'bbb': 2, 'ccc': 1, 'ddd': 5} [('ccc', 1), ('bbb', 2), ('aaa', 3), ('ddd', 5)]
a[0] 则是按照key值来排序
