我有一个“抽象”类,例如:
class A:
def do_some_cool_stuff():
''' To override '''
pass
def do_some_boring_stuff():
return 2 + 2
B 类,A 类的子类:
class B(A):
def do_stuff()
return 4
有什么方法可以声明A.do_some_cool_stuff
必须方法被重写,并且可能在尝试创建 B 类时应该发出一些警告对象,当 B 还没有实现 A.do_some_cool_stuff
时?
最佳答案
是的,通过将 A
定义为 ABC (Abstract Base Class) :
from abc import ABCMeta, abstractmethod
class A(object):
__metaclass__ = ABCMeta
@abstractmethod
def do_some_cool_stuff():
''' To override '''
pass
def do_some_boring_stuff():
return 2 + 2
您可以子类化 A
,但是如果 do_some_cool_stuff()
方法具有具体实现,您只能创建此类子类的实例:
>>> from abc import ABCMeta, abstractmethod
>>> class A(object):
... __metaclass__ = ABCMeta
... @abstractmethod
... def do_some_cool_stuff():
... ''' To override '''
... pass
... def do_some_boring_stuff():
... return 2 + 2
...
>>> class B(A):
... def do_stuff():
... return 4
...
>>> B()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: Can't instantiate abstract class B with abstract methods do_some_cool_stuff
关于python - 在 Python 中是否可以声明必须重写该方法?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/17402622/