day7装饰器作业（最后一题待补充）

# 一：编写函数，（函数执行的时间是随机的）
import time
import random
# def foo():
#     time.sleep(random.randrange(1,5))
#     print(‘haha‘)
# foo()
# 二：编写装饰器，为函数加上统计时间的功能
# def timmer(func):
#     def wrapper():
#         start_time=time.time()
#         func()
#         stop_time=time.time()
#         print(‘run time is %s‘%(stop_time-start_time))
#     return wrapper
# @timmer
# def foo():
#     time.sleep(random.randrange(1,5))
#     print(‘haha‘)
# foo()
# 三：编写装饰器，为函数加上认证的功能
# def auth(func):
#     def deco():
#         name=input(‘name: ‘)
#         pwd=input(‘password: ‘)
#         if name==‘egon‘ and pwd==‘123‘:
#             print(‘login successful‘)
#             func()
#         else:
#             print(‘login erro‘)
#     return deco
# @auth
# def foo():
#     time.sleep(random.randrange(1,5))
#     print(‘haha‘)
# foo()
# 四：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
#     注意：从文件中读出字符串形式的字典，可以用eval(‘{"name":"egon","password":"123"}‘)转成字典格式
# user_dic={
#     ‘egon‘:‘123‘,
#     ‘alex‘:‘alex3714‘,
#     ‘wupeiqi‘:‘wu13‘,
#     ‘yuanhao‘:‘123123‘
# }
# with open(‘db.txt‘,‘w‘,encoding=‘utf-8‘) as f:
#     f.write(str(user_dic))
# with open(‘db.txt‘,‘r‘,encoding=‘utf-8‘) as f:
#     res=f.read()
#     #print(res,type(res))#字符串类型
#     user_dic=eval(res)
#     #print(user_dic,type(user_dic))#字典类型
# db_path=‘db.txt‘
# login_dic={
#     ‘user‘:None,
#     ‘status‘:False,
# }
# def auth(func):
#     def wrapper(*args,**kwargs):
#         if login_dic[‘user‘] and login_dic[‘status‘]:
#             res = func(*args, **kwargs)
#             return res
#         name=input(‘your name: ‘)
#         password=input(‘your password: ‘)
#         with open(db_path,‘r‘,encoding=‘utf-8‘) as f:
#             user_dic=eval(f.read())
#         if name in user_dic and password == user_dic[name]:
#                 print(‘login ok‘)
#                 login_dic[‘user‘]=name
#                 login_dic[‘status‘]=True
#                 res=func(*args,**kwargs)
#                 return res
#         else:
#             print(‘login err‘)
#     return wrapper
# @auth #auth(index)
# def index():
#     print(‘welecome to index‘)
# @auth
# def home(name):
#     print(‘welecome %s to home page‘ %name)
# index()
# home(‘egon‘)
# 五：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
# from urllib.request import urlopen
# def index(url):
#     def get():
#         return urlopen(url).read()
#     return get
# python = index(‘https://www.python.org‘)
# print(python())
# 六：为题目五编写装饰器，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
# from urllib.request import urlopen
# import os
# cache_path=r‘C:\Users\Administrator\PycharmProjects\python5期\day8\cache.txt‘
# def make_cache(func):
#     def wrapper(*args,**kwargs):
#         if os.path.getsize(cache_path):
#             #有缓存,文件不为空
#             print(‘\033[45m=========>有缓存\033[0m‘)
#             with open(cache_path,‘rb‘) as f:
#                 res=f.read()
#         else:
#             res=func(*args,**kwargs) #下载
#             with open(cache_path,‘wb‘) as f: #制作缓存
#                 f.write(res)
#         return res
#     return wrapper
# @make_cache
# def get(url):
#     return urlopen(url).read()
# print(‘================>first‘)
# print(get(‘https://www.python.org‘))
# print(‘================>second‘)
# print(get(‘https://www.python.org‘))
# print(‘================>third‘)
# print(get(‘https://www.python.org‘))
# 七：还记得我们用函数对象的概念，制作一个函数字典的操作吗，
# 来来来，我们有更高大上的做法，在文件开头声明一个空字典，
# 然后在每个函数前加上装饰器，完成自动添加到字典的操作
# func_dic = {}
# def deco(key):
#     def deco2(func):
#         func_dic[key]=func
#     return deco2
# @deco(‘f1‘)#@deco2  func1=deco2(func1)
# def func1():
#     print("from f1")
# @deco(‘f2‘)
# def func2():
#     print("from f2")
# @deco(‘f3‘)
# def func3():
#     print("from f3")
# print(func_dic)
# while True:
#     cmd=input(‘>>: ‘).strip()
#     if cmd in func_dic:
#         func_dic[cmd]()