day11 作业
# 1.编写装饰器,为多个函数加上认证的功能(用户的账号密码来源于文件),
# 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
from res import *
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("input username: ").strip()
_password = input("input password: ").strip()
if _username == username and _password == password:
Flag = True
ret = func(*args, **kwargs)
return ret
else:
print('登录失败')
return inner
@login
def read():
print("读一本书")
@login
def write():
print("写一篇文章")
read()
write()'''
#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 wrapper(func):
def innner(*args,**kwargs):
with open("res","a",encoding="utf-8") as f:
f.write(func.__name__+'
')
ret = func(*args,**kwargs)
return ret
return innner
@wrapper
def fan():
print('fan')
@wrapper
def yzx():
print("yzx")
fan()
yzx()
# 进阶作业(选做):
# 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)
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)
ret = get('http://www.baidu.com')
print(ret)
ret = get('http://www.baidu.com')
print(ret)