gym序列化、EzPickle類

EzPickle是一個用於強化學習環境的類，它重寫了__getstate__和__setstate__方法，以便透過建構函式引數(*args,**kwargs)進行序列化和反序列化。這個設計允許那些無法直接用pickle庫處理的物件，如資料庫連線和網路套接字，也能在儲存和恢復時保持其狀態。

"""Class for pickling and unpickling objects via their constructor arguments."""
from typing import Any


class EzPickle:
    """Objects that are pickled and unpickled via their constructor arguments.

    Example:
        >>> class Animal: pass
        >>> class Dog(Animal, EzPickle):
        ...    def __init__(self, furcolor, tailkind="bushy"):
        ...        Animal.__init__(self)
        ...        EzPickle.__init__(self, furcolor, tailkind)

    When this object is unpickled, a new ``Dog`` will be constructed by passing the provided furcolor and tailkind into the constructor.
    However, philosophers are still not sure whether it is still the same dog.

    This is generally needed only for environments which wrap C/C++ code, such as MuJoCo and Atari.
    """

    def __init__(self, *args: Any, **kwargs: Any):
        """Uses the ``args`` and ``kwargs`` from the object's constructor for pickling."""
        self._ezpickle_args = args
        self._ezpickle_kwargs = kwargs

    def __getstate__(self):
        """Returns the object pickle state with args and kwargs."""
        return {
            "_ezpickle_args": self._ezpickle_args,
            "_ezpickle_kwargs": self._ezpickle_kwargs,
        }

    def __setstate__(self, d):
        """Sets the object pickle state using d."""
        out = type(self)(*d["_ezpickle_args"], **d["_ezpickle_kwargs"])
        self.__dict__.update(out.__dict__)

    def __init__(
        self,
        forward_reward_weight=1.0,
        ctrl_cost_weight=0.1,
        reset_noise_scale=0.1,
        exclude_current_positions_from_observation=True,
        **kwargs,
    ):
        utils.EzPickle.__init__(
            self,
            forward_reward_weight,
            ctrl_cost_weight,
            reset_noise_scale,
            exclude_current_positions_from_observation,
            **kwargs,
        )