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@zengxiankui 2017-08-04T13:11:20.000000Z 字数 16040 阅读 2061

Python装饰器分类

Python

装饰器函数: 是指装饰器本身是函数风格的实现;
函数装饰器: 是指被装饰的目标对象是函数;(目标对象);
装饰器类 : 是指装饰器本身是类风格的实现;
类装饰器 : 是指被装饰的目标对象是类;(目标对象);

一、装饰器函数:

1、目标对象是函数:

(1)、装饰器无参数:

A、目标无参数:

  1. strOldFunctionName = "";
  2. strNewFunctionName = "";
  3. #装饰器无参数:
  4. def decorator(callback): #装饰器函数/外部函数,它接受一个函数对象作为参数(这个函数一般就是目标函数);
  5.     #目标无参数:
  6.     def wrapper():       #闭包函数,用于传递目标函数的所有参数(没有参数);
  7.         strOldFunctionName = callback.__name__;
  8.         print "装饰前的函数名: %s" % strOldFunctionName;
  9.         print "enter {}()".format(callback.__name__);
  10.         callback();      #调用目标函数,执行原有功能;
  11.         print "leave {}()".format(callback.__name__);
  12.         pass;
  13.     return wrapper;      #返回闭包函数对象;
  15. @decorator  #装饰器无参数;
  16. def target():  #目标函数:需要增加功能的函数(没有参数);
  17.     strNewFunctionName = target.__name__;
  18.     print "装饰后的函数名: %s" % strNewFunctionName;
  19.     pass;
  21. target(); #用装饰过的新函数;
  22. print "函数名变化: %s --> %s" % (strOldFunctionName, strNewFunctionName)

B、目标有参数:

  1. strOldFunctionName = "";
  2. strNewFunctionName = "";
  3. #装饰器无参数:
  4. def decorator(callback):           #装饰器函数/外部函数,它接受一个函数对象作为参数(这个函数一般就是目标函数);
  5.     #目标有参数:
  6.     def wrapper(*args, **kwargs):  #闭包函数,用于传递目标函数的所有参数(任意参数);
  7.         strOldFunctionName = callback.__name__;
  8.         print "装饰前的函数名: %s" % strOldFunctionName;
  9.         print "enter {}()".format(callback.__name__);
  10.         callback(*args, **kwargs); #调用目标函数,执行原有功能;
  11.         print "leave {}()".format(callback.__name__);
  12.         pass;
  13.     return wrapper;  #返回闭包函数对象;
  15. @decorator #装饰器无参数;
  16. def target0(): #目标函数:需要增加功能的函数(没有参数) ;
  17.     strNewFunctionName = target0.__name__;
  18.     print "装饰后的函数名target0 = %s" % strNewFunctionName;
  19.     pass;
  21. @decorator #装饰器无参数;
  22. def target1(a): #目标函数:需要增加功能的函数(1个参数) ;
  23.     print "a = ", a;
  24.     strNewFunctionName = target1.__name__;
  25.     print "装饰后的函数名target1 = %s" % strNewFunctionName;
  26.     pass;
  28. @decorator #装饰器无参数;
  29. def target2(a, b): #目标函数:需要增加功能的函数(2个参数) ;
  30.     print "a = ", a, ", b = ", b;
  31.     strNewFunctionName = target2.__name__;
  32.     print "装饰后的函数名target2 = %s" % strNewFunctionName;
  33.     pass;
  35. target0();     #调用装饰过的新函数;
  36. target1(6);    #调用装饰过的新函数;
  37. target2(2, 8); #调用装饰过的新函数;

(2)、装饰器有参数:

A、目标无参数:

  1. strOldFunctionName = "";
  2. strNewFunctionName = "";
  3. #装饰器有参数:
  4. def decorator(name):       #装饰器函数,参数name可以作为关键字使用(可选的特点);
  5.     def wrapper(callback): #内嵌一级闭包函数wrapper(),用于传递目标函数对象;接受一个函数对象作为参数(这个函数一般就是目标函数);
  6.         #目标无参数:
  7.         def _wrapper(): #二级闭包函数_wrapper()用于传递目标函数的所有参数(没有参数);
  8.             strOldFunctionName = callback.__name__;
  9.             print "装饰前的函数名: %s" % strOldFunctionName;
  10.             print "{name}: enter {func}()".format(name = name, func = callback.__name__); #打印输出:通过关键字模式"{name}"打印,关键字name与format()的name关键字参数相同,func雷同;
  11.             callback(); #调用目标函数,执行原有功能(没有参数);
  12.             print "{name}: leave {func}!".format(name = name, func = callback.__name__);  #打印输出:通过关键字模式"{name}"打印,关键字name与format()的name关键字参数相同,func雷同;
  13.             pass;
  14.         return _wrapper; #在一级闭包函数中返回二级闭包函数对象;
  15.     return wrapper; #在装饰器函数中返回一级闭包函数对象;
  17. #装饰器有参数:
  18. @decorator(name = "SYSTEM")  #装饰目标函数,参数name被用作关键字参数传递(可选参数的特点);
  19. def target(): #目标无参数;
  20.     strNewFunctionName = target.__name__;
  21.     print "装饰后的函数名target = %s" % strNewFunctionName;
  22.     pass;
  24. target(); #调用装饰过的新函数;

B、目标有参数:

  1. strOldFunctionName = "";
  2. strNewFunctionName = "";
  3. #装饰器有参数:
  4. def decorator(name):       #装饰器函数,参数name可以作为关键字使用(可选的特点);
  5.     def wrapper(callback): #内嵌一级闭包函数wrapper(),用于传递目标函数对象;接受一个函数对象作为参数(这个函数一般就是目标函数);
  6.         #目标有参数:
  7.         def _wrapper(*args, **kwargs): #二级闭包函数_wrapper()用于传递目标函数的所有参数;
  8.             strOldFunctionName = callback.__name__;
  9.             print "装饰前的函数名: %s" % strOldFunctionName;
  10.             print "{name}: enter {func}()".format(name = name, func = callback.__name__); #打印输出:通过关键字模式"{name}"打印,关键字name与format()的name关键字参数相同,func雷同;
  11.             callback(*args, **kwargs); #调用目标函数,执行原有功能;
  12.             print "{name}: leave {func}!".format(name = name, func = callback.__name__);  #打印输出:通过关键字模式"{name}"打印,关键字name与format()的name关键字参数相同,func雷同;
  13.             pass;
  14.         return _wrapper; #在一级闭包函数中返回二级闭包函数对象;
  15.     return wrapper; #在装饰器函数中返回一级闭包函数对象;
  17. #装饰器有参数:
  18. @decorator(name = 'SYSTEM') #装饰目标函数,参数name被用作关键字参数传递(可选参数的特点);
  19. def target3(a, b, c):
  20.     strNewFunctionName = target3.__name__;
  21.     print "装饰后的函数名target = %s" % strNewFunctionName;
  22.     print "a = %d, b = %d, c = %d" % (a, b, c);
  23.     pass;
  25. #装饰器有参数:
  26. @decorator('PROCESS')       #装饰目标函数,参数name没有被用作关键字参数传递;
  27. def target2(x, y):
  28.     strNewFunctionName = target2.__name__;
  29.     print "装饰后的函数名target = %s" % strNewFunctionName;
  30.     print "x = %d, y = %d" % (x, y);
  31.     pass;
  33. target2(6, 8);    #调用装饰过的新函数;
  34. target3(4, 6, 8); #调用装饰过的新函数;

2、目标对象是类:

(1)、装饰器无参数:

A、目标无参数:

  1. strOldClassName = "";
  2. strNewClassName = "";
  3. #装饰器无参数:
  4. def decorator(cls): #装饰器,它没有参数,只是接受类对象作为参数(被装饰的目标类);
  5.     #目标无参数:
  6.     def wrapper(): #一级闭包函数,它负责传递类的构造函数需要用到的参数(没有参数);
  7.         strOldClassName = cls.__name__;
  8.         print "装饰前的类名: %s" % strOldClassName;
  9.         print "call {name}.__init__".format(name = cls.__name__);
  10.         objCls = cls(); #调用原始类的构造函数(没有参数);
  11.         return objCls;  #返回新的类对象(被装饰过的目标类对象);
  12.     return wrapper; #返回一级闭包函数对象;
  14. @decorator
  15. class target:
  16.     def __init__(self): #目标无参数;
  17.         strNewClassName = target.__name__;
  18.         print "装饰后的类名: %s" % strNewClassName;
  19.         pass;
  21.     def echo(self, msg):
  22.         print "echo: ", msg;
  23.         pass;
  25. t = target(); #用装饰过的新类创建对象;
  26. t.echo("XXXXXXXXXXXX");

B、目标有参数:

  1. strOldClassName = "";
  2. strNewClassName = "";
  3. #装饰器无参数:
  4. def decorator(cls): #装饰器,它没有参数,只是接受类对象作为参数(被装饰的目标类);
  5.     #目标有参数:
  6.     def wrapper(*args, **kwargs): #一级闭包函数,它负责传递类的构造函数需要用到的参数;
  7.         strOldClassName = cls.__name__;
  8.         print "装饰前的类名: %s" % strOldClassName;
  9.         print "call {name}.__init__".format(name = cls.__name__);
  10.         objCls = cls(*args, **kwargs); #调用原始类的构造函数;
  11.         return objCls;  #返回新的类对象(被装饰过的目标类对象);
  12.     return wrapper; #返回一级闭包函数对象;
  14. @decorator
  15. class target1:
  16.     def __init__(self, arg): #目标有参数;
  17.         self.arg = arg;
  18.         print "arg = ", arg;
  19.         strNewClassName = target1.__name__;
  20.         print "装饰后的类名: %s" % strNewClassName;
  21.         pass;
  23.     def echo(self, msg):
  24.         print "echo: ", msg;
  25.         pass;
  27. @decorator
  28. class target2:
  29.     def __init__(self, arg1, arg2): #目标有参数;
  30.         self.arg1 = arg1;
  31.         self.arg2 = arg2;
  32.         print "arg1 = ", self.arg1, ", arg2 = ", self.arg2;
  33.         strNewClassName = target2.__name__;
  34.         print "装饰后的类名: %s" % strNewClassName;
  35.         pass;
  37.     def echo(self, msg):
  38.         print "echo: ", msg;
  39.         pass;
  41. @decorator
  42. class target3:
  43.     def __init__(self): #目标无参数;
  44.         strNewClassName = target3.__name__;
  45.         print "装饰后的类名: %s" % strNewClassName;
  46.         pass;
  48.     def echo(self, msg):
  49.         print "echo: ", msg;
  50.         pass;
  52. t1 = target1(123);      #用装饰过的新类创建对象;
  53. t1.echo("1111111111");
  54. t2 = target2(456, 789); #用装饰过的新类创建对象;
  55. t1.echo("2222222222");
  56. t3 = target3();         #用装饰过的新类创建对象;
  57. t3.echo("3333333333");

(2)、装饰器有参数:

A、目标无参数:

  1. strOldClassName = "";
  2. strNewClassName = "";
  3. #装饰器有参数:
  4. def decorator(level = 'INFO'): #装饰器,它需要参数;
  5.     def _wrapper(cls):         #一级闭包函数对象,它接受一个类(被装饰的目标类)对象(类也是对象)作为参数;
  6.         #目标无参数:
  7.         def __wrapper(): #二级闭包函数,它负责传递类的构造函数需要用到的参数(没有参数);
  8.             strOldClassName = cls.__name__;
  9.             print "装饰前的类名: %s" % strOldClassName;
  10.             print "[{level}] call {name}.__init__".format(level = level, name = cls.__name__);
  11.             objCls = cls(); #调用原始类的构造函数(没有参数);
  12.             return objCls;  #返回新的类对象(被装饰过的目标类对象);
  13.         return __wrapper;   #返回二级闭包函数对象;
  14.     return _wrapper; #返回一级闭包函数对象;
  16. @decorator()
  17. class target1:
  18.     def __init__(self): #目标无参数;
  19.         strNewClassName = target1.__name__;
  20.         print "装饰后的类名: %s" % strNewClassName;
  21.         pass;
  23.     def echo(self, msg):
  24.         print "echo: ", msg;
  25.         pass;
  27. @decorator("DEBUG")
  28. class target2:
  29.     def __init__(self): #目标无参数;
  30.         strNewClassName = target2.__name__;
  31.         print "装饰后的类名: %s" % strNewClassName;
  32.         pass;
  34.     def echo(self, msg):
  35.         print "echo: ", msg;
  36.         pass;
  38. @decorator(level = "SYSTEM")
  39. class target3:
  40.     def __init__(self): #目标无参数;
  41.         strNewClassName = target3.__name__;
  42.         print "装饰后的类名: %s" % strNewClassName;
  43.         pass;
  45.     def echo(self, msg):
  46.         print "echo: ", msg;
  47.         pass;
  49. t1 = target1(); #用装饰过的新类创建对象;
  50. t1.echo("AAAAAAAA");
  51. t2 = target2(); #用装饰过的新类创建对象;
  52. t2.echo("BBBBBBBB");
  53. t3 = target3(); #用装饰过的新类创建对象;
  54. t3.echo("CCCCCCCC");

B、目标有参数:

  1. strOldClassName = "";
  2. strNewClassName = "";
  3. #装饰器有参数:
  4. def decorator(level = 'INFO'): #装饰器,它需要参数;
  5.     def _wrapper(cls):         #一级闭包函数对象,它接受一个类(被装饰的目标类)对象(类也是对象)作为参数;
  6.         #目标有参数:
  7.         def __wrapper(*args, **kwargs): #二级闭包函数,它负责传递类的构造函数需要用到的参数;
  8.             strOldClassName = cls.__name__;
  9.             print "装饰前的类名: %s" % strOldClassName;
  10.             print "[{level}] call {name}.__init__".format(level = level, name = cls.__name__);
  11.             objCls = cls(*args, **kwargs); #调用原始类的构造函数;
  12.             return objCls;  #返回新的类对象(被装饰过的目标类对象);
  13.         return __wrapper;   #返回二级闭包函数对象;
  14.     return _wrapper; #返回一级闭包函数对象;
  16. @decorator()
  17. class target1:
  18.     def __init__(self, arg):
  19.         self.arg = arg;
  20.         print "arg = ", arg;
  21.         strNewClassName = target1.__name__;
  22.         print "装饰后的类名: %s" % strNewClassName;
  23.         pass;
  25.     def echo(self, msg):
  26.         print "echo: ", msg;
  27.         pass;
  29. @decorator('ERROR')
  30. class target2:
  31.     def __init__(self, arg1, arg2):
  32.         self.arg1 = arg1;
  33.         self.arg2 = arg2;
  34.         print "arg1 = ", self.arg1, ", arg2 = ", self.arg2;
  35.         strNewClassName = target2.__name__;
  36.         print "装饰后的类名: %s" % strNewClassName;
  37.         pass;
  39.     def echo(self, msg):
  40.         print "echo: ", msg;
  41.         pass;
  43. @decorator(level = 'WARN')
  44. class target3:
  45.     def __init__(self):
  46.         strNewClassName = target3.__name__;
  47.         print "装饰后的类名: %s" % strNewClassName;
  48.         pass;
  50.     def echo(self, msg):
  51.         print "echo: ", msg;
  52.         pass;
  54. t1 = target1(123);      #用装饰过的新类创建对象;
  55. t1.echo("1111111111");
  56. t2 = target2(456, 789); #用装饰过的新类创建对象;
  57. t1.echo("2222222222");
  58. t3 = target3();         #用装饰过的新类创建对象;
  59. t3.echo("3333333333");

二、装饰器类:

装饰器本身是一个类,通过构造函数__init__()和回调函数__call__()实现装饰器功能;

1、目标对象是函数:

(1)、装饰器无参数:

A、目标无参数:

  1. #装饰器无参数:
  2. class decorator:  #装饰器类,它也可以从object继承"class decorator(object)";
  3.     def __init__(self, callback): #在构造函数里面接受callback对象(原始目标函数对象)作为参数;
  4.         self.callback = callback;
  5.         self.__name__ = callback.__name__; #保证被装饰之后函数名字不变;
  6.         pass;
  8.     #目标无参数:
  9.     def __call__(self): #在__call__()函数中传递目标函数对象的所有参数(没有参数);
  10.         print "装饰前的函数名: %s" % self.callback.__name__;
  11.         print "enter {func}()".format(func = self.callback.__name__);
  12.         result = self.callback();
  13.         print "leave {func}()".format(func = self.callback.__name__);
  14.         return result;
  16. @decorator
  17. def target():
  18.     print "装饰后的函数名: %s" % target.__name__;
  19.     pass;
  21. target(); #调用装饰过的新函数;

B、目标有参数:

  1. #装饰器无参数:
  2. class decorator:  #装饰器类,它也可以从object继承"class decorator(object)";
  3.     def __init__(self, callback): #在构造函数里面接受callback对象(原始目标函数对象)作为参数;
  4.         self.callback = callback;
  5.         self.__name__ = callback.__name__; #保证被装饰之后函数名字不变;
  6.         pass;
  8.     #目标有参数:
  9.     def __call__(self, *args, **kwargs): #在__call__()函数中传递目标函数对象的所有参数(任意参数);
  10.         print "装饰前的函数名: %s" % self.callback.__name__;
  11.         print "enter {func}()".format(func = self.callback.__name__);
  12.         result = self.callback(*args, **kwargs); #传递任意参数;
  13.         print "leave {func}()".format(func = self.callback.__name__);
  14.         return result;
  16. @decorator
  17. def target0():
  18.     print "装饰后的函数名: %s" % target0.__name__;
  19.     pass;
  21. @decorator
  22. def target1(a, b):
  23.     print "a = %d, b = %d" % (a, b);
  24.     print "装饰后的函数名: %s" % target1.__name__;
  25.     pass;
  27. target0();     #调用装饰过的新函数;
  28. target1(6, 8); #调用装饰过的新函数;

(2)、装饰器有参数:

A、目标无参数:

  1. #装饰器有参数:
  2. class decorator:
  3.     def __init__(self, name = 'INFO'): #在装饰器的构造函数中传递装饰器类需要的参数;
  4.         self.name = name;
  5.         pass;
  7.     #目标无参数:
  8.     def __call__(self, callback): #在__call__()函数中接受callback对象(原始目标函数对象)作为参数;
  9.         def wrapper(): #内部闭包函数,给目标函数增加额外的功能(没有参数);
  10.             print "装饰后的函数名: %s" % callback.__name__;
  11.             print "[{name}] enter {func}()".format(name = self.name, func = callback.__name__);
  12.             result = callback();  #调用原始目标函数,没有参数;
  13.             print "[{name}] leave {func}()".format(name = self.name, func = callback.__name__);
  14.             return result;
  15.         return wrapper; #返回新的目标函数对象;
  17. @decorator()
  18. def target0():
  19.     print "装饰后的函数名: %s" % target0.__name__;
  20.     pass;
  22. @decorator('ERROR')
  23. def target1():
  24.     print "装饰后的函数名: %s" % target1.__name__;
  25.     pass;
  27. @decorator(name = 'SYSTEM')
  28. def target2():
  29.     print "装饰后的函数名: %s" % target2.__name__;
  30.     pass;
  32. target0(); #调用装饰过的新函数;
  33. target1(); #调用装饰过的新函数;
  34. target2(); #调用装饰过的新函数;

B、目标有参数:

  1. #装饰器有参数:
  2. class decorator:
  3.     def __init__(self, name = 'INFO'): #在装饰器的构造函数中传递装饰器类需要的参数;
  4.         self.name = name;
  5.         pass;
  7.     #目标有参数:
  8.     def __call__(self, callback): #在__call__()函数中接受callback对象(原始目标函数对象)作为参数;
  9.         def wrapper(*args, **kwargs): #内部闭包函数,给目标函数增加额外的功能(任意参数);
  10.             print "装饰后的函数名: %s" % callback.__name__;
  11.             print "[{name}] enter {func}()".format(name = self.name, func = callback.__name__);
  12.             result = callback(*args, **kwargs);  #调用原始目标函数,传递任意参数;
  13.             print "[{name}] leave {func}()".format(name = self.name, func = callback.__name__);
  14.             return result;
  15.         return wrapper; #返回新的目标函数对象;
  17. @decorator()
  18. def target0():
  19.     print "装饰后的函数名: %s" % target0.__name__;
  20.     pass;
  22. @decorator('ERROR')
  23. def target1(a):
  24.     print "装饰后的函数名: %s" % target1.__name__;
  25.     print "a = %d" % (a);
  26.     pass;
  28. @decorator(name = 'SYSTEM')
  29. def target2(x, y):
  30.     print "装饰后的函数名: %s" % target2.__name__;
  31.     print "x = %d, y = %d" % (x, y);
  32.     pass;
  34. target0();     #调用装饰过的新函数;
  35. target1(2);    #调用装饰过的新函数;
  36. target2(6, 8); #调用装饰过的新函数;

2、目标对象是类:

(1)、装饰器无参数:

A、目标无参数:

  1. #装饰器无参数:
  2. class decorator:
  3.     def __init__(self, cls): #在装饰器的构造函数中传递被装饰类的对象;
  4.         self.cls = cls;
  5.         self.__name__ = cls.__name__; #保证被装饰之后类的名字不变;
  6.         pass;
  8.     #目标无参数:
  9.     def __call__(self): #在__call__()函数中接受callback对象(原始目标函数对象)的所有参数(没有参数);
  10.         print "装饰前的类名: %s" % self.cls.__name__;
  11.         print "enter {func}()".format(func = self.cls.__name__);
  12.         objCls = self.cls();  #调用原始类的构造函数,传递任意参数(没有参数);
  13.         print "leave {func}()".format(func = self.cls.__name__);
  14.         return objCls; #返回新的目标类对象;
  16. @decorator #装饰器无参数;
  17. class target:
  18.     def __init__(self): #目标无参数;
  19.         print "装饰后的类名: %s" % target.__name__;
  20.         pass;
  22.     def echo(self, msg):
  23.         print "echo: ", msg;
  24.         pass;
  26. t = target(); #用装饰过的新类创建对象;

B、目标有参数:

  1. #装饰器无参数:
  2. class decorator:
  3.     def __init__(self, cls): #在装饰器的构造函数中传递被装饰类的对象;
  4.         self.cls = cls;
  5.         self.__name__ = cls.__name__; #保证被装饰之后类的名字不变;
  6.         pass;
  8.     #目标有参数:
  9.     def __call__(self, *args, **kwargs): #在__call__()函数中接受callback对象(原始目标函数对象)的所有参数(任意参数);
  10.         print "装饰前的类名: %s" % self.cls.__name__;
  11.         print "enter {func}()".format(func = self.cls.__name__);
  12.         objCls = self.cls(*args, **kwargs);  #调用原始类的构造函数,传递任意参数;
  13.         print "leave {func}()".format(func = self.cls.__name__);
  14.         return objCls; #返回新的目标类对象;
  16. @decorator #装饰器无参数;
  17. class target0:
  18.     def __init__(self): #目标无参数;
  19.         print "装饰后的类名: %s" % target0.__name__;
  20.         pass;
  22.     def echo(self, msg):
  23.         print "echo: ", msg;
  24.         pass;
  26. @decorator #装饰器无参数;
  27. class target1:
  28.     def __init__(self, arg1, arg2): #目标有参数;
  29.         self.arg1 = arg1;
  30.         self.arg2 = arg2;
  31.         print "arg1 = ", self.arg1, ", arg2 = ", self.arg2;
  32.         print "装饰后的类名: %s" % target1.__name__;
  33.         pass;
  35.     def echo(self, msg):
  36.         print "echo: ", msg;
  37.         pass;
  39. @decorator #装饰器无参数;
  40. class target2:
  41.     def __init__(self, arg1): #目标有参数;
  42.         self.arg1 = arg1;
  43.         print "arg1 = ", self.arg1;
  44.         print "装饰后的类名: %s" % target2.__name__;
  45.         pass;
  47.     def echo(self, msg):
  48.         print "echo: ", msg;
  49.         pass;
  51. t1 = target0();     #用装饰过的新类创建对象;
  52. t1.echo("AAAAAAAA");
  53. t2 = target1(6, 8); #用装饰过的新类创建对象;
  54. t2.echo("BBBBBBBB");
  55. t3 = target2(9);    #用装饰过的新类创建对象;
  56. t3.echo("CCCCCCCC");

(2)、装饰器有参数:

A、目标无参数:

  1. #装饰器有参数:
  2. class decorator:
  3.     def __init__(self, name = 'INFO'): #在装饰器的构造函数中传递装饰器类需要的参数;
  4.         self.name = name;
  5.         pass;
  7.     #目标无参数:
  8.     def __call__(self, cls): #在__call__()函数中接受callback对象(原始目标函数对象)作为参数;
  9.         def wrapper(): #内部闭包函数,给目标类增加额外的功能(没有参数);
  10.             print "装饰前的类名: %s" % cls.__name__;
  11.             print "[{name}] enter {func}()".format(name = self.name, func = cls.__name__);
  12.             objCls = cls();  #调用原始类的构造函数(没有参数);
  13.             print "[{name}] leave {func}()".format(name = self.name, func = cls.__name__);
  14.             return objCls;
  15.         return wrapper; #返回新的目标函数对象;
  17. @decorator()            #装饰器有参数;
  18. class target0:
  19.     def __init__(self): #目标无参数;
  20.         print "装饰后的类名: %s" % target0.__name__;
  21.         pass;
  23.     def echo(self, msg):
  24.         print "echo: ", msg;
  25.         pass;
  27. @decorator("DEBUG")     #装饰器有参数;
  28. class target1:
  29.     def __init__(self): #目标无参数;
  30.         print "装饰后的类名: %s" % target1.__name__;
  31.         pass;
  33.     def echo(self, msg):
  34.         print "echo: ", msg;
  35.         pass;
  37. @decorator(name = "SYSTEM") #装饰器有参数;
  38. class target2:
  39.     def __init__(self):     #目标无参数;
  40.         print "装饰后的类名: %s" % target2.__name__;
  41.         pass;
  43.     def echo(self, msg):
  44.         print "echo: ", msg;
  45.         pass;
  47. t1 = target0(); #用装饰过的新类创建对象;
  48. t1.echo("AAAAAAAA");
  49. t2 = target1(); #用装饰过的新类创建对象;
  50. t2.echo("BBBBBBBB");
  51. t3 = target2(); #用装饰过的新类创建对象;
  52. t3.echo("CCCCCCCC");

B、目标有参数:

  1. #装饰器有参数:
  2. class decorator:
  3.     def __init__(self, name = 'INFO'): #在装饰器的构造函数中传递装饰器类需要的参数;
  4.         self.name = name;
  5.         pass;
  7.     #目标有参数:
  8.     def __call__(self, cls): #在__call__()函数中接受callback对象(原始目标函数对象)作为参数;
  9.         def wrapper(*args, **kwargs): #内部闭包函数,给目标类增加额外的功能(任意参数);
  10.             print "装饰前的类名: %s" % cls.__name__;
  11.             print "[{name}] enter {func}()".format(name = self.name, func = cls.__name__);
  12.             objCls = cls(*args, **kwargs);  #调用原始类的构造函数,传递任意参数;
  13.             print "[{name}] leave {func}()".format(name = self.name, func = cls.__name__);
  14.             return objCls;
  15.         return wrapper; #返回新的目标函数对象;
  17. @decorator()            #装饰器有参数;
  18. class target0:
  19.     def __init__(self): #目标无参数;
  20.         print "装饰后的类名: %s" % target0.__name__;
  21.         pass;
  23.     def echo(self, msg):
  24.         print "echo: ", msg;
  25.         pass;
  27. @decorator("DEBUG") #装饰器有参数;
  28. class target1:
  29.     def __init__(self, arg1, arg2): #目标有参数;
  30.         self.arg1 = arg1;
  31.         self.arg2 = arg2;
  32.         print "arg1 = ", self.arg1, ", arg2 = ", self.arg2;
  33.         print "装饰后的类名: %s" % target1.__name__;
  34.         pass;
  36.     def echo(self, msg):
  37.         print "echo: ", msg;
  38.         pass;
  40. @decorator(name = "SYSTEM") #装饰器有参数;
  41. class target2:
  42.     def __init__(self, arg1): #目标有参数;
  43.         self.arg1 = arg1;
  44.         print "arg1 = ", self.arg1;
  45.         print "装饰后的类名: %s" % target2.__name__;
  46.         pass;
  48.     def echo(self, msg):
  49.         print "echo: ", msg;
  50.         pass;
  52. t1 = target0();     #用装饰过的新类创建对象;
  53. t1.echo("AAAAAAAA");
  54. t2 = target1(6, 8);   #用装饰过的新类创建对象;
  55. t2.echo("BBBBBBBB");
  56. t3 = target2(9);    #用装饰过的新类创建对象;
  57. t3.echo("CCCCCCCC");

【备注】:

针对装饰器类用于装饰函数的情况,装饰器类还有如下写法:把内嵌的闭包函数定义成装饰器类的成员函数;
例如:

  1. #装饰器有参数:
  2. class decorator:
  3.     def __init__(self, name = 'INFO'): #在装饰器的构造函数中传递装饰器类需要的参数;
  4.         self.name = name;
  5.         pass;
  7.     #目标有参数:
  8.     def __call__(self, callback): #在__call__()函数中接受callback对象(原始目标函数对象)作为参数;
  9.         self.callback = callback;
  10.         return self.wrapper; #返回新的目标函数对象(闭包函数对象);
  12.     #原来的闭包函数被定义为成员函数:
  13.     def wrapper(*args, **kwargs): #内部闭包函数,给目标函数增加额外的功能(任意参数);
  14.         print "装饰后的函数名: %s" % callback.__name__;
  15.         print "[{name}] enter {func}()".format(name = self.name, func = callback.__name__);
  16.         result = self.callback(*args, **kwargs);  #调用原始目标函数,传递任意参数;
  17.         print "[{name}] leave {func}()".format(name = self.name, func = callback.__name__);
  18.         return result;

【总结】:

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