如何格式化python中继承方法的文档字符串？

Question

我有以下对象，在cars.py

import abc

class Car(abc.ABC):

  def drive(self):
    """This is the docstring for how to drive a {0}."""
    pass

class Van(Car):

  def shut_sliding_door(self):
    pass

class Hybrid(Car):

  def plug_in(self):
    pass

Van.drive.__doc__ = Car.drive.__doc__.format('van')
Hybrid.drive.__doc__ = Car.drive.__doc__.format('hybrid')

但是，Hybrid.drive 的文档字符串是用"van" 字符串而不是"hybrid" 字符串格式化的。

import cars as cars

cars.Hybrid.drive.__doc__
> "This is the docstring for how to drive a van."

cars.Van.drive.__doc__
> "This is the docstring for how to drive a van."

看来Van.drive.__doc__ = Car.drive.__doc__.format('van') 行正在更改字符串Car.drive.__doc__.format('van')。这得到了证实，

cars.Car.drive.__doc__
> "This is the docstring for how to drive a van."

如何将Hybrid.drive.__doc__ 的字符串格式化为"This is the docstring for how to drive a hybrid"？

编辑：

虽然在子类中覆盖drive 方法可以工作，但如果drive 是一个长方法，而我想要在子类中更改它的只是文档字符串呢？

Answer 1

那是因为你没有覆盖子类中的方法。所以一开始，如果你调用 Hybrid.drive 与 Car.drive 完全相同的方法，那么无论你从哪个类访问它，都只存在一个方法

如果你重写它们，你会得到不同的方法，每个都有自己的，所以它自己的文档字符串

class Car(abc.ABC):
    def drive(self):
        """This is the docstring for how to drive a {0}."""
        pass

class Van(Car):
    def shut_sliding_door(self):
        pass
    def drive(self):
        pass

class Hybrid(Car):
    def plug_in(self):
        pass
    def drive(self):
        pass

if __name__ == '__main__':
    Van.drive.__doc__    = Car.drive.__doc__.format('van')
    Hybrid.drive.__doc__ = Car.drive.__doc__.format('hybrid')

    print(Van.drive.__doc__)     # This is the docstring for how to drive a van.
    print(Hybrid.drive.__doc__)  # This is the docstring for how to drive a hybrid.
    print(Car.drive.__doc__)     # This is the docstring for how to drive a {0}.