Python 装饰器简单示例
- 2020 年 1 月 13 日
- 筆記
简单装饰器示例：
def servlet(func): print("into servlet")#1 print(servlet)#2 def foo(): print("into foo")#7 print(func)#8，真正的bar函数 func()#9 print("out foo")#13 print(foo)#3 print("out servlet")#4 return foo @servlet def bar(): print("in old bar")/#0 print(bar)#11 print("out old bar")#12 print(bar)#5，已经被装饰器装饰了 bar()#6
执行顺序如上，执行结果如下
into servlet <function servlet at 0x00000186A1341E18> <function servlet.<locals>.foo at 0x00000186A1801E18> out servlet <function servlet.<locals>.foo at 0x00000186A1801E18> into foo <function bar at 0x00000186A1801AE8> in old bar <function servlet.<locals>.foo at 0x00000186A1801E18> out old bar out foo Process finished with exit code 0
可变参数装饰器示例：
def desc(func): print("in desc") print(desc) def foo(*arg1,**arg2): print("in foo") print(func) x = func(*arg1,**arg2) print("out foo") return x print(foo) print("out desc") return foo @desc def setArg1(x,y): print("in setArg1") print(setArg1) print("out setArg1") return x + y @desc def setArg2(x,y,z): print("in setArg2") print(setArg2) print("out setArg2") return x + y + z print(setArg1) print(setArg2) x = setArg1(100,200) y = setArg2(100,200,300) print(x) print(y)
代码如上，执行结果如下
in desc <function desc at 0x0000024DF2611E18> <function desc.<locals>.foo at 0x0000024DF2AD1E18> out desc in desc <function desc at 0x0000024DF2611E18> <function desc.<locals>.foo at 0x0000024DF2AD1EA0> out desc <function desc.<locals>.foo at 0x0000024DF2AD1E18> <function desc.<locals>.foo at 0x0000024DF2AD1EA0> in foo <function setArg1 at 0x0000024DF2AD1AE8> in setArg1 <function desc.<locals>.foo at 0x0000024DF2AD1E18> out setArg1 out foo in foo <function setArg2 at 0x0000024DF2AD1A60> in setArg2 <function desc.<locals>.foo at 0x0000024DF2AD1EA0> out setArg2 out foo 300 600 Process finished with exit code 0
