17 字典公共功能

1、len

info = {"name":'刘伟达','age':18,'gender':'男','hobby':'同桌'}
print(len(info))

2、索引

info = {"name":'刘伟达','age':18,'gender':'男','hobby':'同桌'}
info['name']
info['age']

3、切片【无】

4、步长【无】

5、for

info = {"name":'刘伟达','age':18,'gender':'男','hobby':'同桌'}

for item in info.keys():
    print(item)

for item in info.values():
    print(item)

for k,v in info.items():
    print(k,v)

6、修改

（存在修改/不存在增加）

# 改值
info = {"name":'刘伟达','age':18,'gender':'男','hobby':'同桌'}
info['age'] = 19
print(info)

# 改键
# 删除后再增加
del info['hobby']
info['xxxxx'] = 'x1'

7、删除

info = {"name":'刘伟达','age':18,'gender':'男','hobby':'同桌'}

del info['name']
print(info)