This extension reformats/prettifies code in a notebook's code cell by black.

pre-requisites: of course, you must have some of the corresponding packages installed:

pip install black [--user]

Then the extension provides

• a toolbar button
• a keyboard shortcut for reformatting the current code-cell (default: Ctrl-B)
• a keyboard shortcut for reformatting whole code-cells (default: Ctrl-Shift-B)

Syntax shall be correct. The extension will also point basic syntax errors.

If you use jupyter-contrib-nbextensions, proceed as usual.

Otherwise, you can still install/try the extension from personal repo, using

jupyter nbextension install https://github.com/drillan/jupyter-black/archive/master.zip --user
jupyter nbextension enable jupyter-black-master/jupyter-black