SimpleImageViewer Import not found about retro HOT 2 OPEN

import hashlib
import struct
from typing import Optional 

# TODO: don't hardcode sizeof_int here
def _bigint_from_bytes(bt: bytes) -> int:
    
    sizeof_int = 4
    padding = sizeof_int - len(bt) % sizeof_int
    bt += b"\0" * padding
    int_count = int(len(bt) / sizeof_int)
    unpacked = struct.unpack(f"{int_count}I", bt)
    accum = 0
    for i, val in enumerate(unpacked):
        accum += 2 ** (sizeof_int * 8 * i) * val
    return accum

def hash_seed(seed: Optional[int] = None, max_bytes: int = 8) -> int:
    """Any given evaluation is likely to have many PRNG's active at once.
    (Most commonly, because the environment is running in multiple processes.)
    There's literature indicating that having linear correlations between seeds of multiple PRNG's can correlate the outputs:
        http://blogs.unity3d.com/2015/01/07/a-primer-on-repeatable-random-numbers/
        http://stackoverflow.com/questions/1554958/how-different-do-random-seeds-need-to-be
        http://dl.acm.org/citation.cfm?id=1276928
    Thus, for sanity we hash the seeds before using them. (This scheme is likely not crypto-strength, but it should be good enough to get rid of simple correlations.)
    Args:
        seed: None seeds from an operating system specific randomness source.
        max_bytes: Maximum number of bytes to use in the hashed seed.
    Returns:
        The hashed seed
    """

    if seed is None:
        seed = create_seed(max_bytes=max_bytes)
    hash = hashlib.sha512(str(seed).encode("utf8")).digest()
    return _bigint_from_bytes(hash[:max_bytes])

gym.utils.seeding.hash_seed = hash_seed

try:
    import pyglet
except ImportError as e:
    raise ImportError(
        """
    Cannot import pyglet.
    HINT: you can install pyglet directly via 'pip install pyglet'.
    But if you really just want to install all Gym dependencies and not have to think about it,
    'pip install -e .[all]' or 'pip install gym[all]' will do it.
    """
    )

try:
    from pyglet.gl import *
except ImportError as e:
    raise ImportError(
        """
    Error occurred while running `from pyglet.gl import *`
    HINT: make sure you have OpenGL installed. On Ubuntu, you can run 'apt-get install python-opengl'.
    If you're running on a server, you may need a virtual frame buffer; something like this should work:
    'xvfb-run -s \"-screen 0 1400x900x24\" python <your_script.py>'
    """
    )
from gym.utils import seeding

gym_version = tuple(int(x) for x in gym.__version__.split('.'))

__all__ = ['RetroEnv']


def get_window(width, height, display, **kwargs):
    """
    Will create a pyglet window from the display specification provided.
    """
    screen = display.get_screens()  # available screens
    config = screen[0].get_best_config()  # selecting the first screen
    context = config.create_context(None)  # create GL context

    return pyglet.window.Window(
        width=width,
        height=height,
        display=display,
        config=config,
        context=context,
        **kwargs
    )

def get_display(spec):
    """Convert a display specification (such as :0) into an actual Display
    object.
    Pyglet only supports multiple Displays on Linux.
    """
    if spec is None:
        return pyglet.canvas.get_display()
        # returns already available pyglet_display,
        # if there is no pyglet display available then it creates one
    elif isinstance(spec, str):
        return pyglet.canvas.Display(spec)
    else:
        raise error.Error(
            "Invalid display specification: {}. (Must be a string like :0 or None.)".format(
                spec
            )
        )

class SimpleImageViewer(object):
    def __init__(self, display=None, maxwidth=500):
        self.window = None
        self.isopen = False
        self.display = get_display(display)
        self.maxwidth = maxwidth

    def imshow(self, arr):
        if self.window is None:
            height, width, _channels = arr.shape
            if width > self.maxwidth:
                scale = self.maxwidth / width
                width = int(scale * width)
                height = int(scale * height)
            self.window = get_window(
                width=width,
                height=height,
                display=self.display,
                vsync=False,
                resizable=True,
            )
            self.width = width
            self.height = height
            self.isopen = True

            @self.window.event
            def on_resize(width, height):
                self.width = width
                self.height = height

            @self.window.event
            def on_close():
                self.isopen = False

        assert len(arr.shape) == 3, "You passed in an image with the wrong number shape"
        image = pyglet.image.ImageData(
            arr.shape[1], arr.shape[0], "RGB", arr.tobytes(), pitch=arr.shape[1] * -3
        )
        texture = image.get_texture()
        gl.glTexParameteri(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_MAG_FILTER, gl.GL_NEAREST)
        texture.width = self.width
        texture.height = self.height
        self.window.clear()
        self.window.switch_to()
        self.window.dispatch_events()
        texture.blit(0, 0)  # draw
        self.window.flip()

#from gym.envs.classic_control.rendering import SimpleImageViewer