如dict={1:‘a‘,2:‘b‘},要得到一个字典dict={1:‘a‘,2:‘b‘,3:{1:‘a‘,2:‘b‘}}
1 >>> dict={1:‘a‘,2:‘b‘} 2 >>> dict 3 {1: ‘a‘, 2: ‘b‘} 4 >>> dict[3]={1: ‘a‘} 5 >>> dict 6 {1: ‘a‘, 2: ‘b‘, 3: {1: ‘a‘}} 7 >>> dict[3].update({2: ‘b‘}); 8 >>> dict 9 {1: ‘a‘, 2: ‘b‘, 3: {1: ‘a‘, 2: ‘b‘}} 10 >>>
上面分为2个步骤;
下来访问嵌套字典:
1 >>> dict[3][1] 2 ‘a‘ 3 >>> dict[3][2] 4 ‘b‘ 5 >>> dict[1] 6 ‘a‘ 7 >>> dict[2] 8 ‘b‘ 9 >>>
原文：http://www.cnblogs.com/yuzhuwei/p/4090806.html