'''
多層裝飾器
'''
def deco1(func): #func=deco2 def wrapper1(*args, **kwargs): '''this is wrapper1''' print('start 1') result = func(*args, **kwargs)# wrapper2() print('end 1') return result return wrapper1def deco2(func):#func=deco1 def wrapper2(*args, **kwargs): '''this is wrapper2''' print('start 2') result = func(*args, **kwargs)# wrapper3() print('end 2') return result return wrapper2def deco3(func):#func=foo def wrapper3(*args, **kwargs): '''this is wrapper3''' print('start 3') result = func(*args, **kwargs)#wrapper1() print('end 3') return result return wrapper3@deco1##deco1(deco2(deco3(foo)))@deco2 #deco2(deco3(foo))@deco3 #deco3(foo)def foo(x, y): '''this is foo''' return x * yprint(foo(8, 9))#wrapper1(wrapper2( wrapper3(foo)))執行從外往內'''輸出結果: start 1 start 2 start 3 end 3 end 2 end 1 72''''''裝飾的過程: wrapper3 = deco3(foo) wrapper2 = deco2(wrapper3) wrapper1 = deco1(wrapper2) foo = wrapper1執行的過程:正好和裝飾的過程相反。 foo(8, 9)--->wrapper1(8, 9)--->deco1(wrapper2)(8, 9)---> | v deco1( deco2( deco3(foo) ) )(8, 9)<---deco1( deco2(wrapper3) )(8, 9) 類比穿衣服,穿(裝飾)的時候從裏往外一層套一層,脫(執行)的時候從外到裏一層一層脫。'''