无法用 pickle 序列化 pygame.Surface 对象

Question

我正在使用 python 3.6 开发游戏，我希望在其多人游戏版本中将由客户端（玩家）修改的服务器对象发送到我想将它们序列化以进行传输的服务器。我在我的对象中使用 pygame 和因此 pygame.Surface

我有这种结构的对象：

class Cargo(Bateau):
  dictCargos = dict()
  def __init__(self, map, nom, pos, armateur=None):
    Bateau.__init__(self, map, nom, armateur, pos)
    self.surface = pygame.image.load(f"images/{self.nom}.png").convert_alpha()
    self.rect = self.map.blit(self.surface, self.pos)
    ...
    Cargo.dictCargos[self.nom] = self

当我序列化另一个没有 pygame 实例的对象时，没关系 但是对于上述对象，我会收到以下错误消息：

import pickle as pickle
pickle.dump(Cargo.dictCargos, open('file2.pkl', 'wb'), protocol=pickle.HIGHEST_PROTOCOL)

Traceback (most recent call last):
  File "./pytransit.py", line 182, in <module>
    encreG(joueur, event)
  File "/home/patrick/Bureau/PyTransit/modulesJeu/tests.py", line 25, in encreG
    pickle.dump(Cargo.dictCargos, open('file2.pkl', 'wb'), protocol=pickle.HIGHEST_PROTOCOL)
TypeError: can't pickle pygame.Surface objects

您知道如何将这些项目传输到服务器吗？或者绕过这个泡菜限制？
如果我想保存一个零件也会出现同样的问题，所以保存这些对象

Answer 1

这是@IonicSolutions 在 cmets 中指出的示例：

import pickle
import pygame


class Test:
    def __init__(self, surface):
        self.surface = surface
        self.name = "Test"

    def __getstate__(self):
        state = self.__dict__.copy()
        surface = state.pop("surface")
        state["surface_string"] = (pygame.image.tostring(surface, "RGB"), surface.get_size())
        return state

    def __setstate__(self, state):
        surface_string, size = state.pop("surface_string")
        state["surface"] = pygame.image.fromstring(surface_string, size, "RGB")
        self.__dict__.update(state)


t = Test(pygame.Surface((100, 100)))
b = pickle.dumps(t)
t = pickle.loads(b)

print(t.surface)

要查看可以使用哪些模式将数据存储为字符串（此处为“RGB”），请查看 into the documentation

Answer 2

根据@MegaIng 的答案，我开发了他/她的答案，这样您就可以正常使用 pygame.Surface，但添加了 pickle 功能。它不应该打扰您的任何代码。我已经在 python 3.7、64 位上对其进行了测试，并且可以正常工作。也已经在我的项目中尝试/实施它，没有受到任何干扰。

import pygame as pg

pgSurf = pg.surface.Surface

class PickleableSurface(pgSurf):
    def __init__(self, *arg,**kwarg):
        size = arg[0]

        # size given is not an iterable,  but the object of pgSurf itself
        if (isinstance(size, pgSurf)):
            pgSurf.__init__(self, size=size.get_size(), flags=size.get_flags())
            self.surface = self
            self.name='test'
            self.blit(size, (0, 0))

        else:
            pgSurf.__init__(self, *arg, **kwarg)
            self.surface = self
            self.name = 'test'

    def __getstate__(self):
        state = self.__dict__.copy()
        surface = state["surface"]

        _1 = pg.image.tostring(surface.copy(), "RGBA")
        _2 = surface.get_size()
        _3 = surface.get_flags()
        state["surface_string"] = (_1, _2, _3)
        return state

    def __setstate__(self, state):
        surface_string, size, flags = state["surface_string"]

        pgSurf.__init__(self, size=size, flags=flags)

        s=pg.image.fromstring(surface_string, size, "RGBA")
        state["surface"] =s;
        self.blit(s,(0,0));self.surface=self;
        self.__dict__.update(state)

这是一个例子

pg.Surface = PickleableSurface
pg.surface.Surface = PickleableSurface

surf = pg.Surface((300, 400), pg.SRCALPHA|pg.HWSURFACE)
# Surface, color, start pos, end pos, width
pg.draw.line(surf, (0,0,0), (0,100), (200, 300), 2)  

from pickle import loads, dumps

dump = dumps(surf)
loaded = loads(dump)
pg.init()
screen = pg.display.set_mode((300, 400))
screen.fill((255, 255, 255))
screen.blit(loaded, (0,0))
pg.display.update()

然后在我的屏幕上：

谢谢@MegaIng

附注： 我还添加了将 unpickle-able pygame surface 转换为 pickle-able surface 的功能，方法是 newSurface = PickleableSurface(PygameSurface) 但是，它只测试过一次，因此可能存在一些错误。如果你找到了，请随时告诉我！我希望它会帮助你！ :D