python 阿貍的進階之路(4)

裝飾器

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#1、開放封閉原則：對擴展開放，對修改是封閉
#2、裝飾器：裝飾它人的，器指的是任意可調用對象，現在的場景裝飾器-》函數，被裝飾的對象也是-》函數
#原則：1、不修改被裝飾對象的源代碼 2、不修改被裝飾對象的調用方式
#裝飾器的目的：在遵循1,2的前提下為被裝飾對象添加上新功能

?（1）無參數類型

import time
def outer(func):def inner():time.sleep(1)print("hello")func()return inner

def bar():print('world')

?（2）有參數類型

# 有參裝飾器
import timedef auth2(engine='file'):def auth(func): # func=indexdef inner(*args,**kwargs):if engine == 'file':name=input('name>>: ').strip()password=input('password>>: ').strip()if name == 'egon' and password == '123':print('login successful')return func(*args,**kwargs)else:print('login err')elif engine == 'mysql':print('mysql auth')elif engine == 'ldap':print('ldap auth')else:print('engin not exists')return innerreturn auth@auth2(engine='mysql') #@auth #index=auth(index) #index=inner
def index(name):time.sleep(1)print('welecome %s to index' %name)return 1111res=index('egon') #res=inner('egon')
print(res)

（3）并列裝飾器

import time
def timmer(func):def inner(*args,**kwargs):start=time.time()res=func(*args,**kwargs)stop=time.time()print('run time is %s' %(stop-start))return resreturn innerdef auth2(engine='file'):def auth(func): # func=indexdef inner(*args,**kwargs):    # 一致if engine == 'file':name=input('name>>: ').strip()password=input('password>>: ').strip()if name == 'egon' and password == '123':print('login successful')res = func(*args,**kwargs) #一致return reselse:print('login err')elif engine == 'mysql':print('mysql auth')elif engine == 'ldap':print('ldap auth')else:print('engin not exists')return innerreturn auth@auth2(engine='file')
@timmer
def index(name):time.sleep(1)print('welecome %s to index' %name)return 1111res=index('egon')
print(res)

（4）

from functools import wraps
import time
def timmer(func):@wraps(func)def inner(*args,**kwargs):start=time.time()res=func(*args,**kwargs)stop=time.time()print('run time is %s' %(stop-start))return res# inner.__doc__=func.__doc__# inner.__name__=func.__name__return inner@timmer
def index(name): #index=inner'''index 函數。。。。。'''time.sleep(1)print('welecome %s to index' %name)return 1111res=index('egon')
print(res)print(help(index))

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