# JupyterLab¶

## 1. Introduction¶

JupyterLab is the next-generation GUI for the Jupyter project, taking over from the standard Jupyter notebook. We use JupyterLab as the OSSCAR development environment.

### a. Installation¶

JupyterLab can be easily installed via pip:

pip install --upgrade jupyterlab


## 2. JupyterLab extensions¶

JupyterLab allows for the development and installation of extensions. For the development of the notebooks, we need to install two JupyterLab extensions.

### a. JupyterLab hide code extension¶

We developed the “jupyterlab-hide-code” extension, which runs all code cells of the current notebook and hides their output. It is useful to quickly check the layout of the notebook’s output. Install it with pip:

pip install --upgrade jupyterlab-hide-code


Once installed it shall show up as a button with an eye icon in the toolbar of the current notebook. One can toggle to hide or show the source codes by clicking the button.

### b. Voila extension¶

The Voila package provides a JupyterLab extension. After installing Voila with pip, one will have the Voila extension available in JupyterLab.

pip install --upgrade voila