class 构造函数中的父属性未被初始化 python

Question

当我调用 project_task.fromid() 并尝试访问 project_task.(id/name/type) 时，为什么 Python 告诉我这个 class 没有任何这些属性？

class project_task(task):

    def __init__(self, project_id, name, duration, deadline, done, id = None):
        if not id:
            task.__init__(name, 0)
        else:
            task.fromid(id)

        self.project_id = project_id
        self.duration = duration
        self.deadline = deadline
        self.done = done

    @classmethod
    def fromid(cls, id):
        db.cursor.execute('''SELECT * FROM project_task WHERE id=?''', [id])

        try:
            result = db.cursor.fetchone()
            return cls(result[1], None, result[2], result[3], result[4], id)
        except:
            return None


class task:

    def __init__(self, name, type, id = None):

        self.name = name
        self.type = type
        self.id = id

    @classmethod
    def fromid(cls, id):
        db.cursor.execute(''' SELECT * FROM task WHERE id = ? ''', [id])

        try:
            result = db.cursor.fetchone()
            return cls(result[1], result[2], id)
        except:
            return None

Answer 1

调用超类init时需要传递self。最好的方法是通过 super().

def __init__(self, project_id, name, duration, deadline, done, id = None):
    if not id:
        super(project_task, self).__init__(name, 0)

但是，您的替代构造函数在这样从 init 中调用时将不起作用；发生的事情是您构建了一个任务实例，而他们将其完全丢弃。相反，您应该有一种方法来 return 相关值并将它们分配给 self.

class 构造函数中的父属性未被初始化 python

class attributes not being initialized by parent in constructor python

python

class-method