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[Python Study Notes]字典操作

line color div 鍵值 alex get imp pri cal

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.刪除

 1 >>> info
 2 {stu1102: LongZe Luola, stu1103: XiaoZe Maliya, stu1101: 武藤蘭}
 3 >>> info.pop("stu1101") #標準刪除姿勢
 4 武藤蘭
 5 >>> info
 6 {stu1102: LongZe Luola, stu1103: XiaoZe Maliya}
 7 >>> del
info[stu1103] #換個姿勢刪除 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} #隨機刪除 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 #標準用法
 4 True
 5 >>> info.get("stu1102")  #獲取
 6 LongZe Luola
 7 >>> info["stu1102"] #同上,但是看下面
 8 LongZe Luola
 9 >>> info["stu1105"]  #如果一個key不存在,就報錯,get不會,不存在只返回None
10 Traceback (most recent call last):
11   File "<stdin>", line 1, in <module>
12 KeyError: stu1105

e.獲取鍵值

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

f.合並

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

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(): #會先把dict轉成list,數據裏大時莫用
7     print(k,v)

[Python Study Notes]字典操作