Question: I'm editing an .ipynb file in VS Code using the Jupyter Notebook extension. I can't seem to figure out how to collapse (or expand) cells.

Can someone explain to me how to do this (using hotkeys or not using hotkeys), or give ideas for what I might be doing wrong?

I tried each of the hotkeys shown below, under three sets of conditions: 1. with the blue vertical bar on the left-hand side of my cell input selected, 2. with the blue vertical bar on the left-hand side of my cell output selected, 3. with my cursor in my cell input.

[!["Notebook: Collapse Cell Input" and "Notebook: Collapse Cell Output", with default bindings](https://i.stack.imgur.com/Rxg85.png)](https://i.stack.imgur.com/Rxg85.png)

Answer: 
Currently, the use of this function is not supported in Jupyter of VS Code, you could refer to this link: [Jupyter notebook cell code folding and output view expanding request](https://github.com/microsoft/vscode-jupyter/issues/1629).

Also, please try to use "[Visual Studio Code Insiders](https://code.visualstudio.com/insiders/)", right-click in the cell of Jupyter, and select "`Collapse Cell Input`" or "`Collapse Cell Output`":

before:

[![enter image description here](https://i.stack.imgur.com/dBNeq.png)](https://i.stack.imgur.com/dBNeq.png)

after:

[![enter image description here](https://i.stack.imgur.com/BCgcs.png)](https://i.stack.imgur.com/BCgcs.png)
I'm using version 1.58.2 and this functionality is now available!

Simply right-click a code cell and select 'Collapse Cell Output'.

Alternatively, click a code cell (make sure you are in command mode) and use the keyboard shortcut ⌘K T (on Mac) or Ctrl-K T on Windows.

[![Collapse Cell Output](https://i.stack.imgur.com/a4gi8.png)](https://i.stack.imgur.com/a4gi8.png)