ipycanvas: A Python Canvas for Jupyter
As you may already know, the Jupyter Notebook and JupyterLab are Browser-based applications. Browsers are incredibly powerful, they allow you to swap rich and interactive graphical interfaces containing buttons, sliders, maps, 2D and 3D plots and even video games in your webpages!
All this power is readily made available to the Python ecosystem by Jupyter interactive widgets libraries. Whether you want to create simple controls using ipywidgets, display interactive data on a 2D map with ipyleaflet, plot 2D data using bqplot or plot volumic data with ipyvolume, all of this is made possible thanks to the open-source community.
One powerful tool in the Browser is the HTML5 Canvas element, it allows you to draw 2D or 3D graphics on the webpage. There are two available APIs for the Canvas, the Canvas API which focuses on 2D graphics, and the WebGL API which uses hardware acceleration for 3D graphics.
After some discussions with my work colleague Wolf Vollprecht, we came to the conclusion that it would be a great idea to directly expose the Canvas API to IPython, without making any modification to it. And that’s how we came up with ipycanvas!
ipycanvas: Exposing the Canvas API to IPython
ipycanvas exposes the Canvas API to IPython, making it possible to draw anything you want on a Jupyter Notebook directly in Python! Anything is possible, you can draw custom heatmaps from NumPy arrays, you can implement your own 2D video-game, or you can create yet another IPython plotting library!
ipycanvas provides a low-level API that allows you to draw simple primitives like lines, polygons, arcs, text, images… Once you’re familiar with the API, you’re only limited by your own imagination!
Using Matt Craig’s ipyevents library, you can add mouse and key events to the Canvas and react to user interactions.
If you have a GamePad around, you can also use the built-in Controller widget and make your own video-game in a Jupyter Notebook!
Documentation
Check-out the ipycanvas documentation for more information: ipycanvas.readthedocs.io
Github repository
Give it a star on Github if you like it! github.com/martinRenou/ipycanvas
Try it online!
You can try it without the need of installing anything on your computer just by clicking on the image below:
Installation
Note that you first need to have Jupyter installed on your computer. You can install ipycanvas using pip:
pip install ipycanvas
Or using conda:
conda install -c conda-forge ipycanvas
If you use JupyterLab, you would need to install the JupyterLab extension for ipycanvas (this requires nodejs to be installed):
jupyter labextension install ipycanvas
About the author
My name is Martin Renou, I am a Scientific Software Engineer at QuantStack. Before joining QuantStack, I studied at the aerospace engineering school SUPAERO in Toulouse, France. I also worked at Logilab in Paris and Enthought in Cambridge, UK. As an open-source developer at QuantStack, I worked on a variety of projects, from xtensor and xeus-python in C++ to ipyleaflet and ipywebrtc in Python and Javascript.
