#fromkeys 返回一个字典，所有的value都被初始化为一个值 dic = dict.fromkeys([1,2,3,4,5],True) print(dic) dic = dict.fromkeys([1,2,3,4,5],["a","b"]) print(dic) dic = dict.fromkeys([1,2,3],{1:'a',2:'b',3:'c'}) print(dic){1: True, 2: True, 3: True, 4: True, 5: True} {1: ['a', 'b'], 2: ['a', 'b'], 3: ['a', 'b'], 4: ['a', 'b'], 5: ['a', 'b']} {1: {1: 'a', 2: 'b', 3: 'c'}, 2: {1: 'a', 2: 'b', 3: 'c'}, 3: ...