装饰器进阶

# 缓存页面示例
import os
from urllib.request import urlopen
# 先查看文件里是否有这个网页的内容，内部函数调用调用外部函数的变量，此时变量存在一个文件中，
# 如果没有，就把它写入文件，等第二次进行访问的时候，先进行文件判断，如果存在就直接读，
def cache(func):
    def inner(*args,**kwargs):
        if os.path.getsize('web_cache'):
            with open('web_cache','rb') as f:
                return f.read()
        ret = func(*args,**kwargs)
        with open('web_cache','wb') as f :
            f.write(b'***'+ret)
        return ret
    return inner



@cache
def get(url):
    code = urlopen(url).read()
    return code

ret = get("https://home.cnblogs.com/u/wupeiqi/")
print(ret)
ret = get("https://home.cnblogs.com/u/wupeiqi/")
print(ret)
ret = get("https://home.cnblogs.com/u/wupeiqi/")
print(ret)


把每次添加删除的记录全部存在文件中

# def wrapper(func):
#     def inner(*args,**kwargs):
#
#         ret = func(*args,**kwargs)
#         with open('log1','a',encoding='utf-8') as f:
#             f.write(func.__name__+'
')
#         return ret
#
#     return inner
#
#
#
# @wrapper
# def shoplist_add():
#     print('增加一个函数')
#
#
# @wrapper
# def shoplist_del():
#     print('删除一个')
#
# shoplist_add()
# shoplist_del()


登陆示例，第一次成功后，后续无需每部操作都再次登陆

FLAG = False
def wrapper(func):
    def inner(*args,**kwargs):
        global FLAG
        if FLAG:
            ret = func(*args, **kwargs)
            return ret
        else:
            username = input('username:')
            password = input('passward:')
            if username =='boss_gold' and password == '22222':
                FLAG = True

                ret = func(*args,**kwargs)
                return ret
            else:
                print('登录失败')
    return inner

@wrapper
def shoplist_add():
    print('增加一个函数')


@wrapper
def shoplist_del():
    print('删除一个')
# #
shoplist_add()
shoplist_del()