python第十七天作业

一：编写函数，（函数执行的时间用time.sleep(n)模拟）

import time
def num_func(x,y):
    if x > y:
        res = x-y
    else:
        res= y-x
    time.sleep(2)
    print(res)
    return res

二：编写装饰器，为函数加上统计时间的功能

def timmer(func):
    def wrapper(*args,**kwargs):
        start = time.time()
        res=func(*args,**kwargs)
        end = time.time()
        print(end-start)
        return res
    return wrapper

num_func = timmer(num_func)
num_func(2,5)
print(num_func)

三：编写装饰器，为函数加上认证的功能

def auth(func):
    def wrapper(*args,**kwargs):
        user_name = input('账号:>>').strip()
        user_pwd = input('密码:>>').strip()
        with open(r'db.txt','rb') as f:
            while True:
                msg = f.readline().decode('utf-8')
                if not len(msg):
                    print('账号不存在')
                    return
                if user_name in msg:
                    x,y = msg.strip().split(':')
                    if user_pwd == y:
                        res=func(*args,**kwargs)
                        print('成功')
                        return res
                    else:
                        print('账号密码错误')

    return wrapper

num_func = auth(num_func)
num_func(1,6)

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

login_name = None


def atuh_func(func):
    def wrapper(*args,**kwargs):
        global login_name
        if not login_name:
            user_name = input('账号:>>').strip()
            user_pwd = input('密码:>>').strip()
            with open(r'db.txt','rb') as f:
                while True:
                    msg = f.readline().decode('utf-8')
                    if not len(msg):
                        print('账号不存在')
                        return
                    x, y = msg.strip().split(':')
                    if user_name ==x:
                        if user_pwd == y:
                            res=func(*args,**kwargs)
                            print('成功')
                            login_name = user_name
                            return res
                        else:
                            print('账号密码错误')
        else:
            print('欢迎回来')
            res = func(*args, **kwargs)
            return res
    return wrapper

num_func = atuh_func(num_func)
num_func(1,5)
num_func(1,5)
num_func(1,5)
num_func(1,5)
num_func(1,5)
num_func(1,5)

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

login_name = None
num_time = 0
import time
def num_func(x,y):
    if x > y:
        res = x-y
    else:
        res= y-x
    time.sleep(2)
    print(res)
    return res

def atuh_func(func):
    def wrapper(*args,**kwargs):
        global login_name
        global num_time
        if num_time > 5:
            login_name = None
            cmd = input('登录超时，输入‘P’请重新登录，其他键退出:>>').strip()
            if cmd!='P':
                return
        if not login_name:
            user_name = input('账号:>>').strip()
            user_pwd = input('密码:>>').strip()
            with open(r'db.txt','rb') as f:
                while True:
                    msg = f.readline().decode('utf-8')
                    if not len(msg):
                        print('账号不存在')
                        return
                    x, y = msg.strip().split(':')
                    if user_name ==x:
                        if user_pwd == y:
                            start = time.time()
                            print('登录成功，开始计时')
                            res=func(*args,**kwargs)
                            login_name = user_name
                            end = time.time()
                            num_time = end -start
                            print(num_time)
                            return res
                        else:
                            print('账号密码错误')
        else:
            start1 = time.time()
            print('欢迎回来')
            res = func(*args, **kwargs)
            end1 = time.time()
            one_time = end1 - start1
            num_time += one_time
            return res
    return wrapper

num_func = atuh_func(num_func)
num_func(1,5)
num_func(1,5)
num_func(1,5)
num_func(1,5)
num_func(1,5)
num_func(1,5)

来源：https://www.cnblogs.com/Lance-WJ/p/12552872.html