装饰器

无参装饰器

装饰器

import time
def timmer(func):def wrapper(*args, **keargs):start = time.time()res = indexstop = time.time()print('run time is %f' % (stop - start))return wrapper@timmer # 装饰器   index = timmel(index)
def index():time.sleep(3)  # 把函数运行时间延长三秒print('welconme!')index() # timmer(index()) 个人理解

import timedef timmer(func):   # 闭包函数def wrapper():print(func)start_time=time.time()func()stop_time=time.time()print('run time is %f'%(stop_time-start_time))return wrapper@timmer     # 装饰语法
def index():    # 被装饰对象time.sleep(3)print('welcome!')index()#上面的运行结果
<function index at 0x10217b9d8>
welcome!
run time is 3.000330

import time
def timmer(func):def wrapper(*args,**kwargs):start_time=time.time()func(*args,**kwargs)stop_time=time.time()print('tun time is %f'% (stop_time-start_time))return wrapper@timmer
def home(name):time.sleep(2)print("welconme to %s!"% name)@timmer
def auth(name,passwd):print(name,passwd)@timmer
def tell():print('-'*20)home('egon')
auth('alex','123')
tell()
#上面运行结果
welconme to egon!
tun time is 2.002392
alex 123
tun time is 0.000015
--------------------
tun time is 0.000007

import time
def timmer(func): #计算函数运行时间def wrapper(*args,**kwargs):start_time=time.time()res=func(*args,**kwargs) #func(*args,**kwargs) 如果不赋值,最终打印出来的结果会出现None stop_time=time.time()print('tun time is %f'% (stop_time-start_time))return res  # 要是用到返回值,装饰器也和被装饰的函数一样需要返回值 returnreturn wrapper@timmer
def my_max(x,y): #返回最大值print('from to my_max')res=x if x>y else yreturn resprint(my_max(2,3))

有参装装饰器

def auth2(auth_type):def auth(func):def wrapper(*args,**kwargs):if auth_type == 'file':name=input("username: ")passwd=input("password: ")if name == 'name' and passwd=='123':print('auth successfull')res=func(*args,**kwargs)return reselse:print("auth error")elif auth_type=='sql':print('还不会')return wrapperreturn auth@auth2( auth_type = 'sql' ) # auth index = auth (index)
def index():print('welcome to index.')index()

多层装饰器

# 无参
@ccc
@bbb
@aaa
def func():passfunc=aaa(func)
func=bbb(aaa(func))
func=ccc(bbb(aaa(func)))# 有参
@ccc('c')
@bbb('b')
@aaa('a')
def func():pass
# @aaa('a')
func=aaa('a')(func)
# @bbb('b')
func=bbb('b')(aaa('a')(func))
# @ccc('c')
func=ccc('c')(bbb('b')(aaa('a')(func)))

重复认证

courent_login={'name':None,'login':False} # 登录状态
def auth2(auth_type='file'): # 加了默认参数def auth(func):def wrapper(*args,**kwargs):if courent_login['name'] and courent_login['login']: # 判断是否登录res=func(*args,**kwargs)return res # 已登录直接返回数据if auth_type == 'file':name=input("username: ")passwd=input("password: ")if name == 'name' and passwd=='123':print('auth successfull')res=func(*args,**kwargs)courent_login['name']=name  # 把登录的用户添加到登录状态里面courent_login['login']=True # 把当前用户登录状态添加到courent_loginreturn reselse:print("auth error")elif auth_type=='sql':print('还不会')return wrapperreturn auth
# 定义阶段
@auth2( auth_type = 'file' ) # auth index = auth (index)
def index():print('welcome to index.')@auth2()
def home():print("from to index")# 调用阶段
index()
home()

作业

1

import time
def timmer(func):def wrapper(*args, **kwargs):start = time.time()func(*args,**kwargs)stop = time.time()print('run time is %f' % (stop - start))return wrapper
# 装饰器   index = timmel(index)
@timmer
def index():    # 无参函数time.sleep(3)  # 把函数运行时间延长三秒print('welconme!')@timmer
def auth(name,passwd):  # 有参函数 两个参数print(name,passwd)@timmer
def home(name): # 有参函数 一个参数print(name)index()
auth("egon",'passwd')
home('name')

2

以装饰器来3次登录,不更改源代码的情况下,增加计算函数运行时间

import os,timetag = True
usr_dict = {}
courent_login={'name':None,'login':False} # 避免重复登录
# 计算函数运行时间
def timmer(func):def wrapper(*args, **kwargs):start = time.time()func(*args,**kwargs)stop = time.time()print('run time is %f' % (stop - start))return wrapperdef auth2(auth_type='file'):    # 加了默认参数auth_type='file'def auth(func):def wrapper(*args,**kwargs):if courent_login['name'] and courent_login['login']:res=func(*args,**kwargs)return resif auth_type == 'file':with open("usr.conf", encoding="utf8") as usr_file, open("usr1.conf", encoding="utf8", mode="w") as usr1_file:usr_name = usr_file.read()usr_dict = eval(usr_name)count = 0tag = Truewhile tag:usrname = input("\t输入'q',退出\nplease username:").strip()if usrname in usr_dict.keys() :passwd = input("please password:").strip()if int(usr_dict[usrname][1]) < 3 and count < 5:if passwd == usr_dict[usrname][0]:res=func(*args,**kwargs)courent_login['name']=usrnamecourent_login['login']=Truereturn reselse:usr_dict[usrname][1] = int(usr_dict[usrname][1]) + 1print("username or password is wrong")usr = str(usr_dict)usr1_file.write(usr)usr1_file.flush()os.rename("usr.conf", "usr2.conf")os.rename("usr1.conf", "usr.conf")else:print("User is locked")continueelif usrname == 'q':print(usr_dict)usr=str(usr_dict)usr1_file.write(usr)usr1_file.flush()os.rename("usr.conf", "usr2.conf")os.rename("usr1.conf", "usr.conf")breakelse:if usrname != usr_dict.keys():count += 1print("not username")elif auth_type=='sql':print("还不会")return wrapperreturn auth@timmer
@auth2(auth_type='file')
def index():print("welcome!")@timmer
@auth2()
def home():print("from to home")index()
home()