JupyterLab

JupyterLab is the next-generation user interface for Jupyter notebooks and is intended to replace the conventional interface. It is a highly modular and customizable interface.

Let’s have a look at how it works. We go to terminal, and type:

$ mkdir jupyterlab-demo
$ cd jupyterlab-demo
$ jupyter-lab

• On Windows, the JupyterLab App can also be launched by clicking on the JupyterLab icon in the Anaconda menu.

Navigation

• Left-hand menu (toggle it with Ctrl(⌘)-b):
  • File browser
    • New launcher
    • New folder
    • Upload files
  • Running terminals and kernels
  • Command palette
  • Cell inspector
  • Open tabs
  • Git integration (if jupyterlab-git extension installed)
  • GitHub browser (if jupyterlab-github extension installed)
• Fully-fledged terminal
• Text editor for source code in different languages
• Code console to run code interactively in a kernel with rich output and linear order
• Modular interface
  • Notebooks, terminals, consoles, data files etc can be moved around
• Classical notebook style is available under the Help menu

Cells

• Markdown cells contain formatted text written in Markdown
• Code cells contain code to be interpreted by the kernel (Python, R, Julia, Octave/Matlab…)

Markdown cells

## Second level heading

This cell contains simple
[markdown](https://daringfireball.net/projects/markdown/syntax), a simple language for writing text that can be automatically converted to other formats, e.g. HTML, LaTeX or any of a number of others.

**Bold**, *italics*, **_combined_**, ~~strikethrough~~, `inline code`.

* bullet points

or

1. numbered
3. lists

**Equations:**
inline $e^{i\pi} + 1 = 0$
or on new line
$$e^{i\pi} + 1 = 0$$

Images:

![Jupyter logo](https://jupyter.org/assets/main-logo.svg)

Links:
[One of many markdown cheat-sheets](https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet#emphasis)

Code cells

# a code cell can run statements of code.
# when you run this cell, the output is sent
# from the web page to a back-end process, run
# and the results are displayed to you
print("hello world")

hello world

Command and edit modes

• To add contents to a cell, you need to enter edit mode by pressing Enter or double-clicking on a cell
• To navigate between cells, create new cells, etc., you need to enter command mode by pressing Escape key or executing the current cell.

Keyboard shortcuts

Some shortcuts only work in Command or Edit mode.

Warning: it can happen that these shortcuts interfer with browser shortcuts.

Discussion point: Integrated development environments

• What tools do you use for developing code?
• How do you compile or execute code?
• How do you debug code?

Some people prefer terminal-based text editors for writing code (e.g. vi/vim, nano, emacs, etc). Others prefer integrated development environments (IDEs), which can bring “everything” one needs for productive programming to one’s fingertips. Yet others prefer code editors, which are light-weight IDEs.

Terminal editor	Code editor	IDE
Good command line skills are needed for effectively using terminal editors	If you use multiple programming languages then code editors offer good support	If you are working with large code bases, then you should definitely checkout the IDE suitable for your programming language
Continue using Emacs and Vim, if you are already proficient	Both IDE and code editors share common features such as code completion, hints, highlighting sections of code	IDEs offer rich support for Debugging and Code refactoring
Supports multiple programming languages	Supports multiple programming languages	Focused on a single language