Embedding in Sphinx documentation

One more option is to include live Panel examples in your Sphinx documentation using the nbsite.pyodide directive.

Setup

In the near future we hope to make this a separate Sphinx extension, until then simply install latest nbsite with pip or conda:

Pip

pip install nbsite

Conda

conda install -c pyviz nbsite

add the extension to the Sphinx conf.py:

extensions += [
    ...,
    'nbsite.pyodide'
]

Configuration

In the conf.py of your project you can configure the extension in a number of ways by defining an nbsite_pyodide_conf dictionary with the following options:

• PYODIDE_URL: The URl to fetch Pyodide from

• autodetect_deps (default=True): Whether to automatically detect dependencies in the executed code and install them.

• enable_pwa (default=True): Whether to add a web manifest and service worker to configure the documentation as a progressive web app.

• requirements (default=['panel']): Default requirements to include (by default this includes just panel.

• scripts: Scripts to add to the website when a Pyodide cell is first executed.

• setup_code (default=''): Python code to run when initializing the Pyodide runtime.

and then you can use the pyodide as an RST directive:

.. pyodide::

   import panel as pn

   slider = pn.widgets.FloatSlider(start=0, end=10, name='Amplitude')

   def callback(new):
       return f'Amplitude is: {new}'

   pn.Row(slider, pn.bind(callback, slider))

Examples

The resulting output looks like this:

import panel as pn

slider = pn.widgets.FloatSlider(start=0, end=10, name='Amplitude')

def callback(new):
    return f'Amplitude is: {new}'

pn.Row(slider, pn.bind(callback, slider))

In addition to rendering Panel components it also renders regular Python types:

1+1

2

"A string"

A string

and also handles stdout and stderr streams:

import numpy as np
for i in range(10):
    print(f'Repeat {i}')
    for i in range(10000):
        np.random.rand(1000)

Repeat 0
Repeat 1
Repeat 2
Repeat 3
Repeat 4
Repeat 5
Repeat 6
Repeat 7
Repeat 8
Repeat 9

raise ValueError('Encountered an error')

Traceback (most recent call last):
  File "/Users/runner/work/panel/panel/panel/io/mime_render.py", line 169, in exec_with_return
    exec(compile(last_ast, "<ast>", "exec"), global_context)
  File "<ast>", line 1, in <module>
ValueError: Encountered an error

and supports _repr_<mime>_ methods that are commonly used by the IPython and Jupyter ecosystem:

class HTML:

    def __init__(self, html):
	    self.html = html

    def _repr_html_(self):
	    return self.html

HTML('<b>HTML!</b>')

HTML!

Usage

The code cell will display a button to execute the cell, which will warn about downloading the Python runtime on first-click and ask you to confirm whether you want to proceed. It will then download Pyodide, all required packages and finally display the output.