python第四天练习题

Posted 2020-10-10

# 一：编写函数，（函数执行的时间是随机的）
# import time
# import random
# def fun1():
#     time.sleep(random.randrange(1, 3))
#     print(random.randrange(1, 3))
# fun1()
# 二：编写装饰器，为函数加上统计时间的功能
# import time
# import random
# def timer(func):
#     # func = fun1
#     def wrapper():
#         star_time = time.time()
#         func()
#         stop_time = time.time()
#         print(‘执行时间：%s‘ % (stop_time - star_time))
#     return wrapper
# @timer
# def fun1():
#     time.sleep(random.randrange(1, 3))
#     print(‘welcome to the page‘)
# fun1()
# 三：编写装饰器，为函数加上认证的功能
# import time
# import random
# def check(func):
#     ‘‘‘
#     修饰器：增加认证功能！
#     :return:
#     ‘‘‘
#     def wrapper(*args,**kwargs):
#         usrname=input("Please input your name: ").strip()
#         pwd=input("Please input your pwd: ").strip()
#         if usrname == "ling"  and pwd == "123":
#             print("Login successful!")
#             func(*args,**kwargs)
#         else:
#             print("Login error!")
#     return wrapper
# @check
# def name(usr):
#     ‘‘‘
#     函数执行时间是随机的。
#     :return:
#     ‘‘‘
#     time.sleep(random.randrange(3,6))
#     print("%s,welcome to the page!" %(usr))
# name("ling")
# 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
# db=‘db.txt‘
# login_status={‘user‘:None,‘status‘:False}
# def auth(auth_type=‘file‘):
#     def auth2(func):
#         def wrapper(*args,**kwargs):
#             if login_status[‘user‘] and login_status[‘status‘]:
#                 return func(*args,**kwargs)
#             if auth_type == ‘file‘:
#                 with open(db,encoding=‘utf-8‘) as f:
#                     dic=eval(f.read())
#                 name=input(‘username: ‘).strip()
#                 password=input(‘password: ‘).strip()
#                 if name in dic and password == dic[name]:
#                     login_status[‘user‘]=name
#                     login_status[‘status‘]=True
#                     res=func(*args,**kwargs)
#                     return res
#                 else:
#                     print(‘username or password error‘)
#             elif auth_type == ‘sql‘:
#                 pass
#             else:
#                 pass
#         return wrapper
#     return auth2
#
# @auth()
# def index():
#     print(‘index‘)
#
# @auth(auth_type=‘file‘)
# def home(name):
#     print(‘welcome %s to home‘ %name)
# index()
# home(‘egon‘)
# 五：编写装饰器，为多个函数加上认证功能，要求登录成功一次，在超时时间内无需重复登录，超过了超时时间，则必须重新登录
# import time,random
# user={‘user‘:None,‘login_time‘:None,‘timeout‘:0.000003,}
#
# def timmer(func):
#     def wrapper(*args,**kwargs):
#         s1=time.time()
#         res=func(*args,**kwargs)
#         s2=time.time()
#         print(‘%s‘ %(s2-s1))
#         return res
#     return wrapper
#
#
# def auth(func):
#     def wrapper(*args,**kwargs):
#         if user[‘user‘]:
#             timeout=time.time()-user[‘login_time‘]
#             if timeout < user[‘timeout‘]:
#                 return func(*args,**kwargs)
#         name=input(‘name>>: ‘).strip()
#         password=input(‘password>>: ‘).strip()
#         if name == ‘egon‘ and password == ‘123‘:
#             user[‘user‘]=name
#             user[‘login_time‘]=time.time()
#             res=func(*args,**kwargs)
#             return res
#     return wrapper
#
# @auth
# def index():
#     time.sleep(random.randrange(3))
#     print(‘welcome to index‘)
#
# @auth
# def home(name):
#     time.sleep(random.randrange(3))
#     print(‘welcome %s to home ‘ %name)
#
# index()
# home(‘egon‘)

# 六：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 get(url):
#     return urlopen(url).read()
# print(get(‘https://www.baidu.com‘))

# 七：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
# import requests
# import os
# cache_file=‘cache.txt‘
# def make_cache(func):
#     def wrapper(*args,**kwargs):
#         if not os.path.exists(cache_file):
#             with open(cache_file,‘w‘):pass
#
#         if os.path.getsize(cache_file):
#             with open(cache_file,‘r‘,encoding=‘utf-8‘) as f:
#                 res=f.read()
#         else:
#             res=func(*args,**kwargs)
#             with open(cache_file,‘w‘,encoding=‘utf-8‘) as f:
#                 f.write(res)
#         return res
#     return wrapper
#
# @make_cache
# def get(url):
#     return requests.get(url).text
# res=get(‘https://www.baidu.com‘)
# print(res)

# 扩展功能：用户可以选择缓存介质/缓存引擎，针对不同的url，缓存到不同的文件中
# import requests,os,hashlib
# engine_settings={
#     ‘file‘:{‘dirname‘:‘./db‘},
#     ‘mysql‘:{
#         ‘host‘:‘127.0.0.1‘,
#         ‘port‘:3306,
#         ‘user‘:‘root‘,
#         ‘password‘:‘123‘},
#     ‘redis‘:{
#         ‘host‘:‘127.0.0.1‘,
#         ‘port‘:6379,
#         ‘user‘:‘root‘,
#         ‘password‘:‘123‘},
# }
#
# def make_cache(engine=‘file‘):
#     if engine not in engine_settings:
#         raise TypeError(‘egine not valid‘)
#     def deco(func):
#         def wrapper(url):
#             if engine == ‘file‘:
#                 m=hashlib.md5(url.encode(‘utf-8‘))
#                 cache_filename=m.hexdigest()
#                 cache_filepath=r‘%s/%s‘ %(engine_settings[‘file‘][‘dirname‘],cache_filename)
#
#                 if os.path.exists(cache_filepath) and os.path.getsize(cache_filepath):
#                     return open(cache_filepath,encoding=‘utf-8‘).read()
#
#                 res=func(url)
#                 with open(cache_filepath,‘w‘,encoding=‘utf-8‘) as f:
#                     f.write(res)
#                 return res
#             elif engine == ‘mysql‘:
#                 pass
#             elif engine == ‘redis‘:
#                 pass
#             else:
#                 pass
#
#         return wrapper
#     return deco
#
# @make_cache(engine=‘file‘)
# def get(url):
#     return requests.get(url).text
#
# # print(get(‘https://www.python.org‘))
# print(get(‘https://www.baidu.com‘))
# 八：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
# route_dic={}
#
# def make_route(name):
#     def deco(func):
#         route_dic[name]=func
#     return deco
# @make_route(‘select‘)
# def func1():
#     print(‘select‘)
#
# @make_route(‘insert‘)
# def func2():
#     print(‘insert‘)
#
# @make_route(‘update‘)
# def func3():
#     print(‘update‘)
#
# @make_route(‘delete‘)
# def func4():
#     print(‘delete‘)
#
# print(route_dic)

# 九 编写日志装饰器，实现功能如：一旦函数f1执行，则将消息2017-07-21 11:12:11 f1 run写入到日志文件中，日志文件路径可以指定
# 注意：时间格式的获取
# import time
# time.strftime(‘%Y-%m-%d %X‘)
# import time
# import os
#
# def logger(logfile):
#     def deco(func):
#         if not os.path.exists(logfile):
#             with open(logfile,‘w‘):pass
#
#         def wrapper(*args,**kwargs):
#             res=func(*args,**kwargs)
#             with open(logfile,‘a‘,encoding=‘utf-8‘) as f:
#                 f.write(‘%s %s run\n‘ %(time.strftime(‘%Y-%m-%d %X‘),func.__name__))
#             return res
#         return wrapper
#     return deco
#
# @logger(logfile=‘aaaaaaaaaaaaaaaaaaaaa.log‘)
# def index():
#     print(‘index‘)
#
# index()