python - 如何使用 Pickle 加载类实例(初学者备份到 pickle jar 中)

Question

我一直在浏览以前的答案，但尚未找到答案。我试图用 pickle 保存和加载类实例，但不断收到错误:类型对象“Foo”没有属性“bar”。我的代码如下:

class Char:
    name = "undefined"

    def __init__(self, race, str, int, dex, con, spd, mp_bonus):
        self.race = race
        self.exp = 0
        self.lvl = 1
        self.str = str
        self.int = int
        self.dex = dex
        self.con = con
        self.spd = spd
        self.hp = (con + str) / 2
        self.current_hp = self.hp
        self.mp_bonus = mp_bonus
        self.mp = (int * mp_bonus)
        self.current_mp = self.mp

    def save(self):
        with open("save.pk1", "wb") as fp:
            pickle.dump(self.__dict__, fp, protocol=pickle.HIGHEST_PROTOCOL)

def load():
    with open('save.pk1', 'rb') as fp:
        Char.__init__ = pickle.load(fp) # no idea what to put here 
                                        # or if it should be in the Char class or not

def options(dude):
    cls()
    print("OPTIONS")
    print("_____________________")
    print("s. Save Game")
    print("l. Load Game")
    print("x. Quit Game")
    print("_____________________")
    select = input("please type in the corresponding letter or number: ")

    if select == "s":
        Char.save(player)
        cls()
        print("Save Complete")
        wait()
        main(dude)
    elif select == "l":
        cls()
        print("Load Complete")
        wait()
        main(dude)
    elif select == "x":
        exit_screen(dude)
    else:
        print("you chose the wrong key")
        wait()
        main(dude)

  def main(dude):
      #menu as written in options above
      select = input("please type in the corresponding letter or number: ")

      if select == "s":
           stats(dude)
      elif select == "i":
           inventory(dude)
      elif select == "1":
           rand_enemy()
      elif select == "o":
           options(dude)
      else:
           print("you chose the wrong key")
           wait()
           main(dude)

   def start_screen(char):
       #menu as written in options above

       select = input("Please type in the corresponding number: ")

       if select == "1":
           get_char(char)
       elif select == "2":
           load()
           main(char)
       elif select == "3":
           exit()
       else:
           print("you chose the wrong key")
           wait()
           start_screen(char)

start_screen(Char)

所以我的主要问题是，当我尝试加载游戏时，它告诉我:AttributeError:类型对象“Char”没有属性“lvl”

虽然我无法理解 pk1 文件，但每次保存都会更新它，所以我知道保存功能正常工作。.我只是不确定如何获取 pk1 文件中的信息并将其替换为 Char .初始化

我正在考虑切换到 JSON，因为我已经在代码的其他部分实现了它..但我希望在这种情况下使用 pickle 让我的生活更轻松

Answer 1

你转储 self.dict 的方法对我来说看起来有点令人费解。转储 Char 类实例的常见方法如下:

class Char:
    def save(self):
        with open("save.pk1", "wb") as fp:
            pickle.dump(self, fp, protocol=pickle.HIGHEST_PROTOCOL)

def load():
    """returns the saved instance of Char"""
    with open('save.pk1', 'rb') as fp:
        return pickle.load(fp)

为了清楚起见，我将添加上述类和方法的用法。

$ python -i 53796917.py
>>> c=Char()
>>> c.lvl = 10
>>> c.save()
>>>
$ python -i 53796917.py
>>> c=load()
>>> c.lvl
10

不抛出任何 AttributeError