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[Python Study Notes]字典操作

时间:2018-01-09 16:42:43      阅读:188      评论:0      收藏:0      [点我收藏+]

标签:blog   import   body   items   note   字典   修改   long   ict   

                     

 字典操作    

                                                                   

 

a.增加

1 >>> info["stu1104"] = "abc"
2 >>> info
3 {stu1102: x5456, stu1104: abc, stu1103: Mali, stu1101: Wu}

 b.修改

1 >>> info[stu1101] = "xinge"
2 >>> info
3 {stu1102: x5456, stu1103:  Mali, stu1101: xinge}

 c.删除

 1 >>> info
 2 {stu1102: LongZe Luola, stu1103: XiaoZe Maliya, stu1101: 武藤兰}
 3 >>> info.pop("stu1101") #标准删除姿势
 4 武藤兰
 5 >>> info
 6 {stu1102: LongZe Luola, stu1103: XiaoZe Maliya}
 7 >>> del info[stu1103] #换个姿势删除
 8 >>> info
 9 {stu1102: LongZe Luola}
10 >>> 
11 >>> 
12 >>> 
13 >>> info = {stu1102: LongZe Luola, stu1103: XiaoZe Maliya}
14 >>> info
15 {stu1102: LongZe Luola, stu1103: XiaoZe Maliya} #随机删除
16 >>> info.popitem()
17 (stu1102, LongZe Luola)
18 >>> info
19 {stu1103: XiaoZe Maliya}

 d.查找

 1 >>> info = {stu1102: LongZe Luola, stu1103: XiaoZe Maliya}
 2 >>> 
 3 >>> "stu1102" in info #标准用法
 4 True
 5 >>> info.get("stu1102")  #获取
 6 LongZe Luola
 7 >>> info["stu1102"] #同上,但是看下面
 8 LongZe Luola
 9 >>> info["stu1105"]  #如果一个key不存在,就报错,get不会,不存在只返回None
10 Traceback (most recent call last):
11   File "<stdin>", line 1, in <module>
12 KeyError: stu1105

 e.获取键值

1 #values
2 >>> info.values()
3 dict_values([LongZe Luola, XiaoZe Maliya])
4 
5 #keys
6 >>> info.keys()
7 dict_keys([stu1102, stu1103])

 

f.合并

1 #update 
2 >>> info
3 {stu1102: LongZe Luola, stu1103: XiaoZe Maliya, stu1106: Alex}
4 >>> b = {1:2,3:4, "stu1102":"龙泽萝拉"}
5 >>> info.update(b)
6 >>> info
7 {stu1102: 龙泽萝拉, 1: 2, 3: 4, stu1103: XiaoZe Maliya, stu1106: Alex}

 

g.深copy

1 import copy
2    
3 n1 = {"k1": "wu", "k2": 123, "k3": ["alex", 456]}
4    
5 n4 = copy.deepcopy(n1)

 

h.循环

1 #方法1
2 for key in info:
3     print(key,info[key])
4  
5 #方法2
6 for k,v in info.items(): #会先把dict转成list,数据里大时莫用
7     print(k,v)

 

[Python Study Notes]字典操作

标签:blog   import   body   items   note   字典   修改   long   ict   

原文地址:https://www.cnblogs.com/liu66blog/p/8251425.html

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