VS Code editing .ipynb file: How to collapse notebook cells?

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.

Answer 1

And another way to collapse cells is coming to v1.64. See

Cell collapsing UI

Notebook cells have a blue bar on the left side to indicate that they are focused. This bar is now interactive - you can click the top part to collapse the cell input, and the bottom part to collapse the output.

• from https://github.com/microsoft/vscode-docs/blob/vnext/release-notes/v1_64.md#cell-collapsing-ui

Answer 2

In my VSCode insiders build version 1.61.0, its working.

What's working ->

 a) One shot expand/collapse all cells(code/output) in '.ipynb'(notebook)
 b) Single cell code/output expand/collapse in '.ipynb'(notebook)
 c) code folding in `.py` file with `#%%` (hierarchy style)

1. for .ipynb (your requirement)

   There is keybinding available: jupyter.notebookeditor.expandallcells/collapseallcells

   what it does?

           Expands/collapses all cells in one shot
   

   Find this setting->

        Top menu File->Preferences->Keyboard Shortcuts
        In search("Type to search in keybindings"...top side) 
        type "Notebook Expand" or "Notebook Collapse", check out:
   
                Notebook: Expand/Collapse All Cells, 
                Notebook: Expand/Collapse Cell Input and 
                Notebook: Expand/Collapse Cell Output
   
   
        Its possible to expand/collapse single/all cells with these shortcuts keys.
   

To make this answer complete (others have answered)->

    1.  double click gutter area (immediate space on left side of code cell) to Expand/Collapse cell (code/output)

    2.  right click on gutter area to get Expand/Collapse cell (code/output)

2. Detailed post for '.ipynb' and '.py' here