11 字典

1 基础

# 基础
my_map = {}    # 空列表
my_map1 = {'host':'10.20.30.40'}
my_map2 = {'host':'10.20.30.40',}

print(type(my_map))
print(my_map)
print(type(my_map1))
print(my_map1)
print(type(my_map2))
print(my_map2)

结果：

<class 'dict'>
{}
<class 'dict'>
{'host': '10.20.30.40'}
<class 'dict'>
{'host': '10.20.30.40'}

2 访问 dict

# 访问字典
my_map = {'host':'10.20.30.40', 'port':'8888', 'username':'admin', 'password':'123456'}
print(my_map['host'])
print(my_map['port'])
print(my_map['username'])
print(my_map['password'])

结果：

10.20.30.40
8888
admin
123456

3 dict 增删改

# dict 增删改
my_map = {}
my_map['id'] = 1
my_map['name'] = 'lizi'
my_map['age'] = 18
my_map['height'] = 190  # 增
print(my_map)
my_map['height'] = 200  # 改
print(my_map)
del my_map['height']      # 删除键 height
print(my_map)
my_map.clear()            # 清空
print(my_map)

结果：

{'id': 1, 'name': 'lizi', 'age': 18, 'height': 190}
{'id': 1, 'name': 'lizi', 'age': 18, 'height': 200}
{'id': 1, 'name': 'lizi', 'age': 18}
{}

4 dict 遍历

# dict 遍历
my_map = {'host':'10.20.30.40', 'port':'8888', 'username':'admin', 'password':'123456'}
for key in my_map.keys():       # 遍历 keys
    print(my_map[key])

for value in my_map.values():   # 遍历 values
       print(value)

for kv in my_map.items():       # 遍历字典项
       print(type(kv))
       print(kv)

for key,value in my_map.items():    # 遍历键值
    print(key+':'+value)

结果：

10.20.30.40
8888
admin
123456
10.20.30.40
8888
admin
123456
<class 'tuple'>
('host', '10.20.30.40')
<class 'tuple'>
('port', '8888')
<class 'tuple'>
('username', 'admin')
<class 'tuple'>
('password', '123456')
host:10.20.30.40
port:8888
username:admin
password:123456