How to render OpenAI gym in google Colab?

题意 ：如何在Google Colab中渲染OpenAI Gym

问题背景：

I'm trying to use OpenAI gym in google colab. As the Notebook is running on a remote server I can not render gym's environment.

我正在尝试在Google Colab中使用OpenAI Gym。由于Notebook运行在远程服务器上，我无法渲染Gym的环境。

I found some solution for Jupyter notebook, however, these solutions do not work with colab as I don't have access to the remote server.

我发现了一些针对Jupyter notebook的解决方案，然而，这些解决方案不适用于Colab，因为我无法访问远程服务器。

I wonder if someone knows a workaround for this that works with google Colab?

我想知道是否有人知道一个适用于Google Colab的解决方案或变通方法？

问题解决：

Korakot's answer is not correct. Korakot 的回答是不正确的。

You can indeed render OpenAi Gym in colaboratory, albiet kind of slowly using none other than matplotlib.

你确实可以在Google Colab中渲染OpenAI Gym环境，尽管使用matplotlib可能会有点慢。

Heres how: 方法如下：

Install xvfb & other dependencies

安装 xvfb 及其他依赖项

 !apt-get install x11-utils > /dev/null 2>&1

    
 !pip install pyglet > /dev/null 2>&1 
    
 !apt-get install -y xvfb python-opengl > /dev/null 2>&1
    
    
    
    

As well as pyvirtual display :

以及 pyvirtualdisplay：

    !pip install gym pyvirtualdisplay > /dev/null 2>&1
    
    

then import all your libraries, including matplotlib & ipythondisplay :

然后导入所有库，包括 matplotlib 和 ipythondisplay：

 import gym

    
 import numpy as np
    
 import matplotlib.pyplot as plt
    
 from IPython import display as ipythondisplay
    
    
    
    

then you want to import Display from pyvirtual display & initialise your screen size, in this example 400x300... :

然后你需要从 pyvirtualdisplay 导入 Display 并初始化你的屏幕尺寸，在这个例子中为 400x300...：

 from pyvirtualdisplay import Display

    
 display = Display(visible=0, size=(400, 300))
    
 display.start()
    
    
    
    

last but not least, using gym's "rgb_array" render functionally, render to a "Screen" variable, then plot the screen variable using Matplotlib! (rendered indirectly using Ipython display)

最后但同样重要的是，使用 Gym 的 "rgb_array" 渲染函数将图像渲染到一个 "Screen" 变量中，然后使用 Matplotlib 绘制这个屏幕变量！（通过 Ipython display 间接渲染）

 env = gym.make("CartPole-v0")

    
 env.reset()
    
 prev_screen = env.render(mode='rgb_array')
    
 plt.imshow(prev_screen)
    
  
    
 for i in range(50):
    
   action = env.action_space.sample()
    
   obs, reward, done, info = env.step(action)
    
   screen = env.render(mode='rgb_array')
    
  
    
   plt.imshow(screen)
    
   ipythondisplay.clear_output(wait=True)
    
   ipythondisplay.display(plt.gcf())
    
  
    
   if done:
    
     break
    
  
    
 ipythondisplay.clear_output(wait=True)
    
 env.close()
    
    
    
    

Link to my working Colaboratory notebook demoing cartpole:

链接到我的工作 Colaboratory 笔记本，它演示了 CartPole 环境：

https://colab.research.google.com/drive/16gZuQlwxmxR5ZWYLZvBeq3bTdFfb1r_6

Note: not all Gym Environments support "rgb_array" render mode, but most of the basic ones do.

注意：并非所有 Gym 环境都支持 "rgb_array" 渲染模式，但大多数基础环境都支持。