Support for arbitrary python commands in the command palette.

This code lets you inject arbitrary commands into the JLab frontend. There are a variety of reasons why one might want to execute python commands outside of a notebook and a console:

• a predefined NBConvert function that you dont want included in the converted result
• interacting with VCS without including that interaction in the notebook
• etc...

pip install jupyterlab_commands
jupyter labextension install jupyterlab_commands
jupyter serverextension enable --py jupyterlab_commands

def convertMe(request, *args, **kwargs):
    import subprocess, tornado, os, os.path, json
    data = json.loads(tornado.escape.json_decode(request.body))
    path = os.path.join(os.getcwd(), data['path'])
    subprocess.run(["jupyter", "nbconvert", path, '--to', 'html'])
    return {'body': 'ok'}

c.JupyterLabCommands.commands = {'sample_command': convertMe}

Moved to jupyterlab_nbconvert_nocode

pip install jupyterlab_commands
jupyter labextension install jupyterlab_commands
jupyter serverextension enable --py jupyterlab_commands

install the server extension, and add the following to jupyter_notebook_config.py

c.JupyterLabCommands.commands = {'command display name': python_function, ...}