# -*- coding:gbk -*-'''示例1: 最簡單的函數,表示調用了兩次'''def myfunc():  print("myfunc() called.")myfunc()myfunc()

# -*- coding:gbk -*-'''示例2: 替換函數(裝飾)裝飾函數的參數是被裝飾的函數對象，返回原函數對象裝飾的實質語句: myfunc = deco(myfunc)''' def deco(func):  print("before myfunc() called.")  func()  print(" after myfunc() called.")  return funcdef myfunc():  print(" myfunc() called.")myfunc = deco(myfunc)myfunc()myfunc()

# -*- coding:gbk -*-'''示例3: 使用語法糖@來裝飾函數，相當于“myfunc = deco(myfunc)”但發現新函數只在第一次被調用，且原函數多調用了一次''' def deco(func):  print("before myfunc() called.")  func()  print(" after myfunc() called.")  return func@decodef myfunc():  print(" myfunc() called.")myfunc()myfunc()

# -*- coding:gbk -*-'''示例4: 使用內嵌包裝函數來確保每次新函數都被調用，內嵌包裝函數的形參和返回值與原函數相同，裝飾函數返回內嵌包裝函數對象''' def deco(func):  def _deco():    print("before myfunc() called.")    func()    print(" after myfunc() called.")    # 不需要返回func，實際上應返回原函數的返回值  return _deco@decodef myfunc():  print(" myfunc() called.")  return 'ok'myfunc()myfunc()

# -*- coding:gbk -*-'''示例5: 對帶參數的函數進行裝飾，內嵌包裝函數的形參和返回值與原函數相同，裝飾函數返回內嵌包裝函數對象'''def deco(func):  def _deco(a, b):    print("before myfunc() called.")    ret = func(a, b)    print(" after myfunc() called. result: %s" % ret)    return ret  return _deco@decodef myfunc(a, b):  print(" myfunc(%s,%s) called." % (a, b))  return a + bmyfunc(1, 2)myfunc(3, 4)

# -*- coding:gbk -*-'''示例6: 對參數數量不確定的函數進行裝飾，參數用(*args, **kwargs)，自動適應變參和命名參數'''def deco(func):  def _deco(*args, **kwargs):    print("before %s called." % func.__name__)    ret = func(*args, **kwargs)    print(" after %s called. result: %s" % (func.__name__, ret))    return ret  return _deco@decodef myfunc(a, b):  print(" myfunc(%s,%s) called." % (a, b))  return a+b@decodef myfunc2(a, b, c):  print(" myfunc2(%s,%s,%s) called." % (a, b, c))  return a+b+cmyfunc(1, 2)myfunc(3, 4)myfunc2(1, 2, 3)myfunc2(3, 4, 5)

# -*- coding:gbk -*-'''示例7: 在示例4的基礎上，讓裝飾器帶參數，和上一示例相比在外層多了一層包裝。裝飾函數名實際上應更有意義些'''def deco(arg):  def _deco(func):    def __deco():      print("before %s called [%s]." % (func.__name__, arg))      func()      print(" after %s called [%s]." % (func.__name__, arg))    return __deco  return _deco@deco("mymodule")def myfunc():  print(" myfunc() called.")@deco("module2")def myfunc2():  print(" myfunc2() called.")myfunc()myfunc2()

# -*- coding:gbk -*-'''示例8: 裝飾器帶類參數'''class locker:  def __init__(self):    print("locker.__init__() should be not called.")  @staticmethod  def acquire():    print("locker.acquire() called.（這是靜態方法）")  @staticmethod  def release():    print(" locker.release() called.（不需要對象實例）")def deco(cls):  '''cls 必須實現acquire和release靜態方法'''  def _deco(func):    def __deco():      print("before %s called [%s]." % (func.__name__, cls))      cls.acquire()      try:        return func()      finally:        cls.release()    return __deco  return _deco@deco(locker)def myfunc():  print(" myfunc() called.")myfunc()myfunc()

# -*- coding:gbk -*-'''mylocker.py: 公共類 for 示例9.py'''class mylocker:  def __init__(self):    print("mylocker.__init__() called.")  @staticmethod  def acquire():    print("mylocker.acquire() called.")  @staticmethod  def unlock():    print(" mylocker.unlock() called.")class lockerex(mylocker):  @staticmethod  def acquire():    print("lockerex.acquire() called.")  @staticmethod  def unlock():    print(" lockerex.unlock() called.")def lockhelper(cls):  '''cls 必須實現acquire和release靜態方法'''  def _deco(func):    def __deco(*args, **kwargs):      print("before %s called." % func.__name__)      cls.acquire()      try:        return func(*args, **kwargs)      finally:        cls.unlock()    return __deco  return _deco

# -*- coding:gbk -*-'''示例9: 裝飾器帶類參數，并分拆公共類到其他py文件中同時演示了對一個函數應用多個裝飾器'''from mylocker import *class example:  @lockhelper(mylocker)  def myfunc(self):    print(" myfunc() called.")   @lockhelper(mylocker)  @lockhelper(lockerex)  def myfunc2(self, a, b):    print(" myfunc2() called.")    return a + bif __name__=="__main__":  a = example()  a.myfunc()  print(a.myfunc())  print(a.myfunc2(1, 2))  print(a.myfunc2(3, 4))