python - 尝试使用类函数在第二个类中调用该类中的另一个函数时获取 "AttributeError"

Question

我正在编写一个小程序，它使用pickle让人们在本地将他们的时间表/工资表保存到他们的计算机上。

我有以下类(class):

class ScheduleDataService:

    def create_object_path(self, active_user):

        users_object_path = root / "user_objects" / active_user
        return users_object_path

    def save_users_schedule(self, users_schedule, users_object_path, active_user):
        schedule = open(users_object_path, "wb")
        pickle.dump(users_schedule, schedule)
        schedule.close()

        logger.debug("\nYour schedule has been successfully saved \n")
        logger.info(active_user + "has successfully saved their schedule.")

    def load_users_schedule(self, active_user):
        users_object_path = self.create_object_path(active_user)
        schedule = open(users_object_path, "rb")
        users_schedule = pickle.load(schedule)
        schedule.close()

        return users_schedule

在这个类中，我在类函数“load_users_schedule”内部调用类函数“create_object_path”。

在同一模块内，我有一个第二类，用于查看用户当前的日程安排:

class ViewSchedule:

    __schedule_data_service: ScheduleDataService

    def __init__(self, schedule_data_service):
        self.__schedule_data_service = schedule_data_service

    def view_day(self, day_to_see, active_user):
        users_schedule = self.__schedule_data_service.load_users_schedule(self, active_user)


        to_view = []

        if day_to_see == "1":
            to_view.append("Monday")
        elif day_to_see == "2":
            to_view.append("Tuesday")
        elif day_to_see == "3":
            to_view.append("Wednesday")
        elif day_to_see == "4":
            to_view.append("Thursday")
        elif day_to_see == "5":
            to_view.append("Friday")
        elif day_to_see.lower() == "all":
            to_view = ["Monday", "Tuesday", "Wednesday", "Thursday", "Friday"]
        else:
            logger.debug("Sorry that isn't a valid option please try again")
            logger.info(active_user + "failed to view " + day_to_see + " from their schedule due to incorrect input")
            pass

        for day in users_schedule.week:
            if day.name in to_view:
                logger.debug("")
                for session in day.sessions:
                    logger.debug("Day: " + day.name + " Class Code: " + session.code + " Class length: "
                                 + session.length)
                logger.debug("")

我试图让这个类成为上面类的自己的实例。然后我尝试调用“load_users_schedule”函数来加载用户时间表。当我这样做时，我收到以下错误。

File "generator.py", line 116, in <module>
    ViewSchedule(ScheduleDataService).view_day(day_to_see, active_user)
  File "/shared/projects/pay_sheet_generator/schedule_data.py", line 249, in view_day
    users_schedule = self.__schedule_data_service.load_users_schedule(self, active_user)
  File "/shared/projects/pay_sheet_generator/schedule_data.py", line 40, in load_users_schedule
    users_object_path = self.create_object_path(active_user)
AttributeError: 'ViewSchedule' object has no attribute 'create_object_path'

当我从“load_users_schedule”中删除“create_object_path”并独立运行它们时，代码可以正常工作。我正在寻找的是一种能够将函数嵌入到彼此内部的方法，如上所示，或者解释为什么我不应该这样做。

编辑:

对 ViewSchedule 的调用如下所示

ViewSchedule(ScheduleDataService).view_day(day_to_see, active_user)

Answer 1

您的代码中存在一些问题。

1. 在 users_schedule = self.__schedule_data_service.load_users_schedule(self, active_user) 行上，您不需要添加 self 作为第一个参数，因为当您使用实例调用类的方法，第一个参数会自动插入该类的实例

2. 您需要将 ScheduleDataService 实例传递给 ViewSchedule 实例，因此您需要执行 ViewSchedule(ScheduleDataService()) 操作。 view_day(day_to_see, active_user) 而不是 ViewSchedule(ScheduleDataService).view_day(day_to_see, active_user)

3. 您还应该知道 dunder 变量是 name-mangled在 python 中，因此在你的类中小心使用它们