# 排序类定义的实例-sorted-attrgetter

代码：

note:`from operator import attrgetter`

```python
class User:
    def __init__(self,user_id):
        self.user_id = users_id
    def __repr__(self):
        return 'User({})'.format(self.user_id)

print('原始','-'*50)
users=[User(19),User(17),User(18)]
print(users)

print('排序1,key=lambda ui:ui.user_id','-'*50)
order_users=sorted(users,key=lambda ui:ui.user_id)#根据user_id降序
print(order_users)

print('排序2,key=lambda ui:ui.user_id,reverse=True','-'*50)
order_users2=sorted(users,key=lambda ui:ui.user_id,reverse=True)#根据user_id升序
print(order_users2)

print('排序3,key=attrgetter(\'user_id\')','-'*50)

from operator import attrgetter
#根据attrgetter获得迭代对象的属性user_id进行排序
order_users3=sorted(users,key=attrgetter('user_id'))
print(order_users3)
```

结果：

```python
原始 --------------------------------------------------
[User(19), User(17), User(18)]
排序1,key=lambda ui:ui.user_id --------------------------------------------
[User(17), User(18), User(19)]
排序2,key=lambda ui:ui.user_id,reverse=True -------------------------------
[User(19), User(18), User(17)]
排序3,key=attrgetter('user_id') ----------------------------------
[User(17), User(18), User(19)]
```

视频：

```
wait
```


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