Resume outputs from an a previously executing cell upload reloading VS Code

[DonJayamanne]

Testing Show whether a remote kernel is busy when reconnecting after reload

Refs: #13276

• anyOS @deepak1556
• web @bamurtaugh

Complexity: 3

Authors: @DonJayamanne

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Requirements

Desktop

• Have a python environment installed
• Have latest VSCode Insiders installed
• Have latest Jupyter and Python pre-release extension installed

Web

• Have a python environment installed and setup with Jupyter on your desktop
• Run jupyter with the following command line
  python -m jupyter notebook --no-browser --NotebookApp.allow_origin='*'
  Note the URL it generates for connecting
  See herefor more information on setting up Jupyter
• Start insiders.vscode.dev
• Make sure Jupyter prerelease extension is installed
• Open a notebook and connect to the above Jupyter server via the Kernel Picker

Steps for DeskTop/Web

• Open a notebook (or create a new Jupyter notebook using the command Create: New Jupyter Notebook)
• Open a notebook and connect to the above Jupyter server via the Kernel Picker (Select Another Source -> Existing Jupyter Server)
• Attempt to run a Python cell with the code print("Hello World") and verify the output is displayed
• Save the notebook
• Run a cell with the following code

import time
for i in range(200):
    time.sleep(1)
    print(i)

• Run the above cell, and verify you can see some of the output starting from 1, 2...
• Reload VS Code
• After reloading, the notebook will be opened and the same kernel will be selected
• A few seconds later you should see the toolbar with the icon Interrupt displayed on the top
• Verify the Interrupt icon is dispalyed in the toolbar
• Verify the Run All icon is NOT dispalyed in the toolbar
• Click on the Interruptbutton and verify you can now run the previous print("Hello World") cell and it runs to completion
• Now create a cell with the following code

import time
for i in range(300):
    time.sleep(1)
    print(i)

• Run the above cell , and verify you can see some of the output starting from 1, 2...
• Reload VS Code (or Exit VS Code completely & restart VS Code)
• After reloading, the notebook will be opened and the same kernel will be selected
• A few seconds later you should see the new output from the counter, e.g. 1.2....8,9,10,11....

[bamurtaugh]

python -m jupyter notebook --no-browser --NotebookApp.allow_origin='*' fails for me, so I adjusted it to python -m notebook --no-browser --NotebookApp.allow_origin='*' - @DonJayamanne let me know if that's alright/expected.

[bamurtaugh]

@DonJayamanne I'm stuck when I reload insiders.vscode.dev - I can't reconnect to a kernel. I describe it here: #13602. I'm blocked at this point on further testing since I can't reconnect after reloading.

cc @rebornix since you helped me with the great steps to connect to a remote Codespaces kernel, in case I'm missing anything else.

[bamurtaugh]

Thanks so much @DonJayamanne for taking the time to unblock my Jupyter setup (and @rebornix for your help earlier)! This is now working great and really cool to see.