Python 裝飾器原理和基本實(shí)現(xiàn)

http://www.cnblogs.com/wupeiqi/articles/4980620.html

http://www.cnblogs.com/vamei

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裝飾器(decorator)是一種高級(jí)Python語法。裝飾器可以對(duì)一個(gè)函數(shù)、方法或者類進(jìn)行加工。在Python中，我們有多種方法對(duì)函數(shù)和類進(jìn)行加工，比如在Python閉包中，我們見到函數(shù)對(duì)象作為某一個(gè)函數(shù)的返回結(jié)果。相對(duì)于其它方式，裝飾器語法簡單，代碼可讀性高。因此，裝飾器在Python項(xiàng)目中有廣泛的應(yīng)用。

裝飾器是設(shè)計(jì)模式的一種，被用于有切面需求的場(chǎng)景，較為經(jīng)典的有插入日志、性能測(cè)試、事務(wù)處理等。

無參數(shù)

def login(func): #func = tvprint("passed user verification.....")#func()return func #return tv的內(nèi)存地方 def home(name):print("Welcome [%s] to home page!" %name) def tv():print("Welcome [%s] to TV page!") def movie(name):print("Welcome [%s] to movie page!" %name) tv = login(tv) tv()/Library/Frameworks/Python.framework/Versions/3.6/bin/python3.6 /Users/admin/PycharmProjects/s18/day3/裝飾器.py passed user verification..... Welcome [%s] to TV page!進(jìn)程已結(jié)束,退出代碼0def login(func): #func = tvprint("passed user verification.....")#func()return func #tv 的內(nèi)存地址 def home(name):print("Welcome [%s] to home page!" %name) @login def tv(name):print("Welcome [%s] to TV page!"%name ) def movie(name):print("Welcome [%s] to movie page!" %name)tv('wwww') # tv = login(tv) # tv('wwww')/Library/Frameworks/Python.framework/Versions/3.6/bin/python3.6 /Users/admin/PycharmProjects/s18/day3/裝飾器.py passed user verification..... Welcome [wwww] to TV page!進(jìn)程已結(jié)束,退出代碼0@login tv = login(tv)

一個(gè)參數(shù)

def login(func): #func = tvdef inner(arg):print("passed user verification.....")#func()return func(arg) #tv 的內(nèi)存地址return inner def home(name):print("Welcome [%s] to home page!" %name) # @login def tv(name):print("Welcome [%s] to TV page!"%name ) def movie(name):print("Welcome [%s] to movie page!" %name)# tv('wwww') tv = login(tv) tv('wwww')

多參數(shù)

def login(func): #func = tvdef inner(*args,**kwargs):print("passed user verification.....")#func()return func(*args,**kwargs) #tv 的內(nèi)存地址return inner def home(name):print("Welcome [%s] to home page!" %name) @login def tv(name,passwd):print("Welcome [%s] to TV page!"%name ) @login def movie(name):print("Welcome [%s] to movie page!" %name)# # tv('wwww') # tv = login(tv) tv('wwww',passwd='123') movie('wwwwwwwww')/Library/Frameworks/Python.framework/Versions/3.6/bin/python3.6 /Users/admin/PycharmProjects/s18/day3/裝飾器.py passed user verification..... Welcome [wwww] to TV page! passed user verification..... Welcome [wwwwwwwww] to movie page!進(jìn)程已結(jié)束,退出代碼0

簡例

http://www.cnblogs.com/wupeiqi/articles/4980620.html def w1(func):def inner(arg):# 驗(yàn)證1# 驗(yàn)證2# 驗(yàn)證3return func(arg)return inner@w1 def f1(arg):print ('f1') print('-------1--------') f1('1111')def w1(func):def inner(arg1,arg2):# 驗(yàn)證1# 驗(yàn)證2# 驗(yàn)證3return func(arg1,arg2)return inner@w1 def f1(arg1,arg2):print ('f1')print('-------2--------') f1('2222','22')def w1(func):def inner(arg1,arg2,arg3):# 驗(yàn)證1# 驗(yàn)證2# 驗(yàn)證3return func(arg1,arg2,arg3)return inner@w1 def f1(arg1,arg2,arg3):print ('f1')print('-------3--------') f1('3333','33','333')def w1(func):def inner(*args,**kwargs):# 驗(yàn)證1# 驗(yàn)證2# 驗(yàn)證3return func(*args,**kwargs)return inner@w1 def f1(arg1,arg2,arg3,arg4):print ('f1') print('-------4--------') f1('4','44','444','4444')def w1(func):def inner(*args,**kwargs):# 驗(yàn)證1# 驗(yàn)證2# 驗(yàn)證3return func(*args,**kwargs)return innerdef w2(func):def inner(*args,**kwargs):# 驗(yàn)證1# 驗(yàn)證2# 驗(yàn)證3return func(*args,**kwargs)return inner@w1 @w2 def f1(arg1,arg2,arg3):print ('f1') print('-------5--------') f1('5','55','555')/Library/Frameworks/Python.framework/Versions/3.6/bin/python3.6 /Users/admin/PycharmProjects/s18/day3/naozi.py -------1-------- f1 -------2-------- f1 -------3-------- f1 -------4-------- f1 -------5-------- f1

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轉(zhuǎn)載于:https://www.cnblogs.com/wangxu01/articles/7457168.html

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