ipycanvas

0.14.3 verified Mon Apr 27 auth: no python

Interactive widgets library exposing the browser's Canvas API for Jupyter notebooks and JupyterLab. Current version 0.14.3. Release cadence: irregular, with multiple releases per year.

pip install ipycanvas

Common errors

error ModuleNotFoundError: No module named 'ipycanvas' ↓

cause ipycanvas is not installed.

fix

Run pip install ipycanvas or conda install -c conda-forge ipycanvas.

error ipycanvas is not displayed in Jupyter notebook ↓

cause The ipywidgets extension may not be enabled or the notebook needs a restart.

fix

Run jupyter nbextension enable --py widgetsnbextension or restart the kernel.

Warnings

breaking In version 0.12.0, the deprecated `size` property was removed. Use `width` and `height` instead. ↓

fix Replace `canvas.size = (200, 200)` with `canvas.width = 200` and `canvas.height = 200`.

gotcha ipycanvas does not support the full HTML5 Canvas API; only a subset of methods is implemented. For example, `getImageData` returns a list instead of ImageData object. ↓

fix Check the documentation for supported methods; use `canvas.get_image_data(x, y, w, h)` which returns a list of RGBA values.

Install

conda install -c conda-forge ipycanvas

Imports

Canvas

wrong

from ipycanvas.widgets import Canvas

correct

from ipycanvas import Canvas

Canvas is exposed at top-level, not in submodule

MultiCanvas
```
from ipycanvas import MultiCanvas
```
No common wrong import known

Quickstart

Create a canvas, set fill style, draw a rectangle, and display.

from ipycanvas import Canvas

canvas = Canvas(width=200, height=200)
canvas.fill_style = 'blue'
canvas.fill_rect(20, 20, 100, 100)
canvas