有没有办法用列表/集合理解来“一行”呢？

Question

下面是我递归获取所有子类的classmethod：

@classmethod
def get_subclasses(cls):
    subclasses = set()
    for subclass in cls.__subclasses__():
        subclasses.add(subclass)
        subclasses.update(subclass.get_subclasses())
    return subclasses

有没有办法把它做成一行的？比如：

return set(subclass.__subclasses__() for subclass in self.__subclasses__())

Answer 1

这是将一个逻辑行拆分为两行源代码以提高可读性：

@classmethod
def get_subclasses(cls):
    return set(cls.__subclasses__()) | {g for s in cls.__subclasses__()
                                            for g in s.get_subclasses()}

Answer 2

一行是可能的，但我认为保持两行可以保持清晰：

subclasses = set(cls.__subclasses__())
return subclasses + set(sc.get_subclasses() for sc in subclasses)

Answer 3

这将返回从基类继承的所有子类的名称。你知道吗

print([cls.__name__ for cls in vars()['Base'].__subclasses__()])