字典的使用
1 #字典dict 2 #无序的根据key索引查找 3 #可以del删除 4 #for循环默认获取key(for i in dict.keys) 5 #获取values(for i in dict.values) 6 #获取键值对(for k,v in dict.items) 7 dic = { 8 "k1":"v1", 9 "k2":"v2" 10 } 11 print(dic) 12 print("#修改:") 13 #修改字典,只能传入一个values 14 v = dic.fromkeys(["k3","k4"],123) 15 print(v) 16 #取值 17 print("#取值:") 18 v = dic.get("k1") 19 print(v) 20 v = dic.get("k1",11111) 21 print(v) 22 v = dic.get("k3",11111) 23 print(v) 24 ############### 25 print("#keys、values、items") 26 v = dic.keys() 27 print(v) 28 v = dic.values() 29 print(v) 30 v = dic.items() 31 print(v) 32 ############## 33 #删除 34 print("#删除:") 35 v = dic.pop("k1")#指定keys删除,输出values 36 print(dic,v) 37 dic = { 38 "k1":"v1", 39 "k2":"v2" 40 } 41 v = dic.popitem()#随机删除|,输出键值对 42 print(dic,v) 43 #设置 44 print("#设置:") 45 dic = { 46 "k1":"v1", 47 "k2":"v2" 48 } 49 v = dic.setdefault("k1","2313123")#如果keys存在则不设置,输出原来keys的值 50 print(dic,v) 51 v = dic.setdefault("k3","2313123")#如果keys不存在则设置,输出设置keys的值 52 print(dic,v) 53 #更新 54 print("#更新:") 55 dic = { 56 "k1":"v1", 57 "k2":"v2" 58 } 59 print(dic) 60 dic.update({"k1":1231}) 61 print(dic) 62 dic.update({"k3":1231}) 63 print(dic) 64 dic.update(k1=1221,k4="wqe") 65 print(dic) 66 #运行结果: 67 {'k1': 'v1', 'k2': 'v2'} 68 #修改: 69 {'k3': 123, 'k4': 123} 70 #取值: 71 v1 72 v1 73 11111 74 #keys、values、items 75 dict_keys(['k1', 'k2']) 76 dict_values(['v1', 'v2']) 77 dict_items([('k1', 'v1'), ('k2', 'v2')]) 78 #删除: 79 {'k2': 'v2'} v1 80 {'k1': 'v1'} ('k2', 'v2') 81 #设置: 82 {'k1': 'v1', 'k2': 'v2'} v1 83 {'k1': 'v1', 'k2': 'v2', 'k3': '2313123'} 2313123 84 #更新: 85 {'k1': 'v1', 'k2': 'v2'} 86 {'k1': 1231, 'k2': 'v2'} 87 {'k1': 1231, 'k2': 'v2', 'k3': 1231} 88 {'k1': 1221, 'k2': 'v2', 'k3': 1231, 'k4': 'wqe'}