1、编写装饰器,为多个函数加上认证功能(用户的账户密码来源文件)
要求登录成功一次,后续的函数都无需再输入用户名和密码
flag = False
def login(func):
def inner(*args,**kwargs):
global flag
"""登录程序"""
if flag:
ret = func(*args,**kwargs)
return ret
else:
username = input('you name: ')
password = input('you password:')
if username == 'dj' and password == '123':
flag = True
ret = func(*args, **kwargs)
return ret
else:
print('logining error')
return inner
@login # shopListAdd = login(shopListAdd)
def shopListAdd():
print('增加物品')
@login
def shopListDel():
print('删除物品')
shopListAdd()
shopListDel()
2、编写装饰器,为多个函数加上记录调用功能,要求每次调用函数都将被调用的函数名称写入文件
def log(func):
def inner(*args,**kwargs):
with open('log',mode='a',encoding='utf-8') as f:
f.write(func.__name__+'
')
ret = func(*args,**kwargs)
return ret
return inner
@log # shopListAdd = log(shopListAdd)
def shopListAdd():
print('增加一件物品')
@log #shopListDel = log(shopListDel)
def shopListDel():
print('删除一件物品')
shopListAdd()
shopListDel()
1.编写下载网页内容的函数,要求功能是:用户传入一个url,函数返回下载页面的结果
2.为题目1编写装饰器,实现缓存网页内容的功能:
具体:实现下载的页面存放于文件中,如果文件内有值(文件大小不为0),就优先从文件中读取网页内容,否则,就去下载,然后存到文件中
import os
from urllib.request import urlopen
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) #get()
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('http://www.baidu.com')
print(ret)