保存和加载类实例

Question

我有一个创建新角色对象的类。

class Character():
    def __init__(self):
    self.name = None
    self.hp = None
    self.mp = None


class Race(Character):
    def __init__(self):
    super().__init__()
    self.race = None

它位于一个名为 char 的模块中。所以我有了创建新游戏的代码。

    elif command == "new game":
        name_game = input('Name your game: ')

        cur_save=open('saves/' + name_game + '.p', 'wb')
        player = char.Character()
        player_name = input('Name your character: ')
        player.name = player_name
        player_race = input('What is your race? ')
        player.race = player_race
        pickle.dump(player, cur_save, -1)
        cur_save.close()

现在我想开始游戏并加载输入的玩家姓名和种族。但以下只是将播放器设置为未定义。

    cur_save=open('saves/' + name_game + '.p', 'rb')
    player = pickle.load(cur_save)

我希望它将 player.name 设置为保存的值，并且与 player.race 相同。 还有什么我应该使用的东西，比如数据库之类的东西（MySQL）

Answer 1

所以我做了一个快速测试，没有任何问题：

import pickle
class Character():
    def __init__(self):
        self.name = None
        self.hp = None
        self.mp = None


class Race(Character):
    def __init__(self):
        super().__init__()
        self.race = None

name_game = input('Name your game: ')

cur_save=open('saves/' + name_game + '.p', 'wb')
player = Character()
player_name = input('Name your character: ')
player.name = player_name
player_race = input('What is your race? ')
player.race = player_race
pickle.dump(player, cur_save, -1)
cur_save.close()

cur_save=open('saves/' + name_game + '.p', 'rb')
player = pickle.load(cur_save)
print(player.name)

我得到的是：

%run temp.py
Name your game: test
Name your character: Brian
What is your race? human
Brian

有时，如果您的类的定义已更改，或者即使您重新定义了该类（可能通过再次运行一些代码），pickle 也会失败。例如，假设我像上面一样运行第一段代码，然后运行

class Character():
    def __init__(self):
        self.name = None
        self.hp = None
        self.mp = None

再次，本质上重新定义了角色。然后你会得到不直观的行为：

In [17]: player.__class__
Out[17]: __main__.Character
In [18]: player.__class__ == Character
Out[18]: False

In [20]: player2 = Character()
In [21]: player2.__class__
Out[21]: __main__.Character
In [22]: player2.__class__ == Character
Out[22]: True

因此，您可能需要确保不会发生类似的事情。通常没关系，但如果变量名发生变化或其他情况，它可能会让你失望。