How to make Jupyter notebook use PYTHONPATH in system variables without hacking sys.path directly?

Question

Same problem as in this question sys.path different in Jupyter and Python - how to import own modules in Jupyter?. In pure Python, it prepends my system environment variable

Answer 1

Use simply the PYTHONPATH.

export PYTHONPATH=/Users/user/my-other-library/
jupyter notebook

I just tested with the newest jupyterlab-2.1.2 and it works.