Find out if my code runs inside a notebook or jupyter lab?

General
17

Your original statement is correct, @fomightez: my “solution” is not universal (actually, I had never tested it for binder bundles).
From your last test, I don’t even think this is the right approach since there is nothing in the psutil command output that can identify a ‘native’ JupyterLab string with ‘lab’ in it (as the user-defined base_url may be totally different than yours).

The function I gave, with the wrong indentation, which you caught, is part of another one which I use as a reminder depending on how I open an existing notebook:

def is_lab_notebook():
    import re
    import psutil

    return any(re.search('jupyter-lab-script', x)
               for x in psutil.Process().parent().cmdline())
                   
def check_notebook():
    """
    Util to check a Jupyter notebook environment:
    a markdown cell in a jupyter lab notebook cannot render
    variables: the cell text needs to be created with
    IPython.display.Markdown.
    """

    if is_lab_notebook():
        # need to use Markdown if referencing variables:
        from IPython.display import Markdown
        msg = "This is a <span style=\"color:red;\">JupyterLab notebook </span>:<br>"
        msg += "* Use `IPython.display.Markdown(F'x = {n}')` if referencing variables. "
        msg += "Using {{n}} directly in a Markdown cell will not work."       
        return Markdown('### {}'.format(msg))
    
check_notebook()