python-code-12

一：编写函数，（函数执行的时间是随机的）

二：编写装饰器，为函数加上统计时间的功能

import time
def timmer(func):
    def wrapper(*args,**kwargs):
        start = time.time()
        res = func(*args,**kwargs)
        stop = time.time()
        print('run time is %s' %(stop - start))
        return res
    return wrapper

@timmer
def index():
    print('welcome to index')
    time.sleep(3)
    return 123
@timmer
def home(name):
    print('welcome %s to home page' %name)
    time.sleep(2)

res = index()
home('egon')

三：编写装饰器，为函数加上认证的功能

import time
def auth(func):
    def wrapper(*args,**kwargs):
        tag = True
        while tag:
            name_inp = input('username>>: ').strip()
            pwd_inp = input('password>>: ')
            with open('db','rt',encoding='utf-8') as f:
                for line in f:
                    line = line.strip('\n').split(':')
                    if name_inp == line[0] and pwd_inp == line[1]:
                        print('认证成功')
                        tag = False
                        break
                else:
                    print('认证失败')
        res=func(*args,**kwargs)
        return res
    return wrapper

@auth # index=auth(index)
def index():
    print('welcome to index')
    time.sleep(3)
    return 123

@auth # home=auth(home)
def home(name):
    print('welcome %s to home page' %name)
    time.sleep(2)

res=index()
home('egon')

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'
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')