每日作业 7/1

1、写一个类，有个name属性，如果name赋值为非字符串，就不让放

class Fun():
    def __init__(self,name,age,male):
        self.name = name
        self.age = age
        self.male = male

    def __setattr__(self, key, value):
        if key == "name":
            if isinstance(value,str):
                super.__setattr__(self, key, value)
            else:
                print("不能赋值非字符串类型")
        else:
            super.__setattr__(self, key, value)

    def __getattr__(self, item):
        print("加点取值会调用我")
        print(type(self.__dict__),self.__dict__)
        return self.__dict__.get(item)

fun = Fun("lxx",18,"male")
fun.name = 13
print(fun.age)

2 通过上下文管理器写一个mysql的连接，通过with管理

import pymysql

class Mysql:
    def __enter__(self):
        print("我在with管理的时候，会触发")
        print('进入with语句块时执行此方法，此方法如果有返回值会赋值给as声明的变量')
        # 链接
        self.conn = pymysql.connect(
            host='127.0.0.1',
            port=3306,
            user='root',
            password='123456',
            database='book_user',
            charset='utf8',
        )
        # 游标
        self.cursor = self.conn.cursor()  # 执行完毕返回的结果集默认以元组显示
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.cursor.close()
        self.conn.close()
        print('退出with代码块时执行此方法')
        # print('1', exc_type)
        # print('2', exc_val)
        # print('3', exc_tb)


with Mysql() as self:   # 这句话执行，会触发类的__enter__
    print(self)
    sql = 'select * from app01_book;'
    rows = self.cursor.execute(sql)
    print(rows)

3 使用django实现token功能