Week 3 Lunar Landing

Course Q&A Machine Learning Specialization Unsupervised Learning, Recommenders, Reinforcement
1

I want to replicate the code for Lunar Lander but have become stuck on this line of code Display(visible=False, size=(840, 480)).start();

I ensured that I loaded the same library version as the course
pip install pyvirtualdisplay==3.0

First I was using ‘google colab’ but that cannot handle Display(visible=False, size=(840, 480)).start(); It did import ‘pyvirtualdisplay’ with no problems. Error message was FileNotFoundError: [Errno 2] No such file or directory: 'Xvfb'.

From what I can understand ‘Xvfb’ is a virtual server that will store pixel values in buffered memory that I can extract and save later as a mp4 file. Google Colab cannot do that.

So I opened Jupyter Notebook and entered the same code. Error this time was FileNotFoundError: [WinError 2] The system cannot find the file specified

So then I tried running it in Pycharm Community, on my PC, and received this error FileNotFoundError: [WinError 2] The system cannot find the file specified.

What step should I take to correct the errors?

I even tried this simple piece of code but encountered the same problem.

import pyvirtualdisplay
d = pyvirtualdisplay.Display()
d.start() # Start Xvfb and set "DISPLAY" environment properly.

and tried these options as well
d=Display()

or

d=Display(visible=False)

or

d=Display(backend="xvfb")

but all the same error code as mentioned above.

2

To run the notebook on Google Colab, you need to install some additional packages. You can do this by executing the following commands in a code cell:

!pip install pyvirtualdisplay
!pip install Box2D
!apt install xvfb
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