Jupyter notebook cannot find module

I’m trying to load a module called folium into my Jupyter Notebook environment. When I attempt to load this module, a ModuleNotFoundError is returned.

When I run !pip list in the same Jupyter Notebook environment, folium is listed amongst my installed modules.

How do I successfully load this module?

Answer

Could it be that you expect a certain Python installation (virtual environment) to be used in Jupyter, but Jupyter is using a different kernel?

With that assumption, I believe all you need to do is to add the virtual environment to Jupyter as a kernel. In more detail:

• Install & activate your virtual environment. Below I’ll use virtualenv, which nowadays seems to be the recommended way of working (see Python docs), but there are other options as well:
  • pip install --user virtualenv if it is not installed yet (it is installed by default for the newer Python versions). By the way, personally, I use Poetry instead of pip for a while now, and I like it a lot.
  • Go to the desired directory (with cd <path>) and create the environment with python3 -m venv <my_venv_name>.
  • Activate the environment with source <my_venv_name>/bin/activate (deactivate with deactivate).
• Make sure ipykernel is installed (pip install --user ipykernel)
• Add the venv to Jupyter with python3 -m ipykernel install --user --name=<any_name_referring_to_your_venv>.

Now you should be able to select in Jupyter this environment as a kernel, and all packages installed in that venv should be picked up by Jupyter automatically as well (you’ll need to restart the kernel in that case though).