Jupyter Notebook
~~~~~~~~~~~~~~~~
The Jupyter Notebook is an open-source web application that allows you to create and share documents that contain live code, equations, visualisations and narrative text. Uses include: data cleaning and transformation, numerical simulation, statistical modeling, data visualisation, machine learning, and much more.


.. _Jupyter Access Loginweb:

Accessing through Login-Web
^^^^^^^^^^^^^^^^^^^^^^^^^^^
All the desktop apps can be found within the ``Interactive Apps`` dropdown in the Login-Web web portal. After selecting Jupyter, you will arrive at this page:

.. image:: ../images/ondemand-apps-jupyter-menu.png
    :alt: Jupyter Notebook

Here you can select the resources you would like your Jupyter session to have using the menu on the right hand side of the page. After you click ``Launch``, a new session will be queued. Once the session is active your page will look like the image below:

.. image:: ../images/ondemand-apps-jupyter-launch.png
    :alt: Jupyter Notebook

You can choose ``Connect to Jupyter`` to start your session and create a ``New`` Python 3 notebook.

.. image:: ../images/ondemand-apps-jupyter-new.png
    :alt: Jupyter Notebook

This is a new notebook with a familiar interface:

.. image:: ../images/ondemand-apps-jupyter.png
    :alt: Jupyter Notebook
	  
Adding virtual environments
^^^^^^^^^^^^^^^^^^^^^^^^^^^

To use your own virtual environments in the Jupyter Notebook app, you need to add them externally. Use the following steps to do so:

1. Use the ``Remote Desktop`` application to log to your CSD3 account, then start a ``Terminal``.

2. If needed, create a new virtual environment using the commands described in the section :ref:`Setup Jupyter on CSD3`

3. **Activate the virtual environment** (otherwise, your installed packages won't be registered)

4. Deploy the python module **ipykernel** with the command line::

    pip install ipykernel

5. Add your virtual environment to the Jupyter Notebook as new kernel, with the command line::

    ipython kernel install --user --name=<virtual environment name>

6. Logout.

7. Start or refresh your jupyter notebook session, as described in the previous section :ref:`Jupyter Access Loginweb`        

8. Start a new logbook by clicking on the button "New" on the right-hand side:
   
.. image:: ../images/ondemand-apps-jupyter-envs.jpg
    :alt: Jupyter Notebook


Your virtual environment should be listed under the selected ``Python3`` as shown in the above illustration. Selecting the virtual environment as kernel will give you access to the python packages you have installed in the virtual environment.

.. image:: ../images/ondemand-apps-jupyter-with-virtual-env.png
    :alt: Jupyter Notebook


Delisting virtual environments
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

To remove unwanted kernels from the Jupyter notebook:

1. Use the ``Remote Desktop`` application to log to your CSD3 account, then start a ``Terminal``.

2. At the prompt::

    module load jupyterlab/3
    jupyter kernelspec list

3. The last command should give you the same list of kernels as the jupyter notebook app. Select the kernel to be deleted, then type::

    jupyter kernelspec uninstall <myenv>