fromkeys() keys() values() items()

 1 fromkeys()
 2 
 3 >>> dict1={}
 4 >>> dict1.fromkeys((1,2,3))#会自动为没有赋值的值建立none
 5 {1: None, 2: None, 3: None}
 6 >>> dict1.fromkeys((1,2,3),'number')＃将前一个括号分别与后面结合成项
 7 {1: 'number', 2: 'number', 3: 'number'}
 8 >>> dict1.fromkeys((1,2,3),('one','two','three'))＃将前面括号分别后后面括号整体结合组成项
 9 {1: ('one', 'two', 'three'), 2: ('one', 'two', 'three'), 3: ('one', 'two', 'three')}
10 >>> dict1.fromkeys((1,3),'good')＃试图修改上一步中，1和3的值，但是结果是新建一个字典，内涵1和3，如果名称相同则会覆盖之前的
11 {1: 'good', 3: 'good'}
12 
13 >>> dict1.fromkeys((1,2,3),('one','two','three'))
14 >>> dict1.fromkeys((1,3),'数字')＃名称相同则会覆盖之前的
15 
16 fromkeys()＃列举32个赞
17 
18 >>> dict1 = dict1.fromkeys(range(32),'赞')
19 
20 keys()＃打印键
21 
22 >>> for eachkey in dict1.keys():
23 print(eachkey)
24 
25 values()＃打印值
26 
27 >>> for eachvalue in dict1.value():
28 print(eachvalue)
29 
30 items()# 打印项
31 
32 >>> for eachValue in dict1.values():
33 print(eachValue)
34 
35 get（）函数
36 
37 >>> dict1.get(31)
38 '赞'
39 >>> dict1.get(32)
40 >>> print(dict1.get(32))
41 None
42 >>> dict1.get(32,'木有')＃前面找不到时就打印后面的内容
43 '木有'
44 >>>