代码示例：

### ref https://www.cnblogs.com/jiangzuofenghua/p/11413777.html
class Printable:
    def _print(self):
        print(111,self.content)

class Document: #第三方库，不允许修改
    def __init__(self,content):
        self.content = content

class Word(Document): pass  #第三方库，不允许修改


class PrintableWord(Printable,Word): pass
print(222,PrintableWord.__dict__)
print(333,PrintableWord.mro())

pw = PrintableWord('test string')
pw._print()

结果：

"D:\Program Files\python_3_6_4\python.exe" D:/untitled2/xdemo.py
222 {'__module__': '__main__', '__doc__': None}
333 [<class '__main__.PrintableWord'>, <class '__main__.Printable'>, <class '__main__.Word'>, <class '__main__.Document'>, <class 'object'>]
111 test string

 

代码示例：

#### ref https://blog.csdn.net/u013008795/article/details/90412084

def printable(cls):
    def _print(self):
        print(self.content,'装饰器')

    cls.print = _print
    return cls

class Document: #第三方库，不允许修改
    def __init__(self,content):
        self.content = content

class Word(Document): pass  #第三方库，不允许修改

@printable #先继承，后装饰
class PrintableWord(Word): pass
print(PrintableWord.__dict__)
print(PrintableWord.mro())
pw = PrintableWord('test string')
pw.print()