Multiple checkbox selection with searching with ipywidgets

01_multi_select_widget_readme.md

Multiple selection with checkboxes and search field

Often, you want the user to choose n options (where n is small-ish) from a very large (hundreds or thousands) number of possibilities. Good UX around this dictates that the user should be able to search for the options they want.

This gist puts together a minimal example of binding a search field with multiple checkboxes using ipywidgets.

Usage

widget = multi_checkbox_widget(['hello', 'world'])
widget # Display the widget

To get the selected options:

selected_options = [widget.description for widget in w.children[1].children if widget.value]

Possible improvements

• This is in need of some layout/CSS TLC.

• At the moment, we just use difflib from the standard library for searching through the options. It mostly works, but I don't think it's what difflib is supposed to be used as. Using a different search algorithm might lead to better results.

main.py

import difflib
import random
import requests
import ipywidgets as widgets


def multi_checkbox_widget(descriptions):
    """ Widget with a search field and lots of checkboxes """
    search_widget = widgets.Text()
    options_dict = {description: widgets.Checkbox(description=description, value=False) for description in descriptions}
    options = [options_dict[description] for description in descriptions]
    options_widget = widgets.VBox(options, layout={'overflow': 'scroll'})
    multi_select = widgets.VBox([search_widget, options_widget])

    # Wire the search field to the checkboxes
    def on_text_change(change):
        search_input = change['new']
        if search_input == '':
            # Reset search field
            new_options = [options_dict[description] for description in descriptions]
        else:
            # Filter by search field using difflib.
            close_matches = difflib.get_close_matches(search_input, descriptions, cutoff=0.0)
            new_options = [options_dict[description] for description in close_matches]
        options_widget.children = new_options

    search_widget.observe(on_text_change, names='value')
    return multi_select

# Example of using the widget

# Get lots of words for our options
words_url = 'https://svnweb.freebsd.org/csrg/share/dict/words?view=co&content-type=text/plain'
response = requests.get(words_url)
response.raise_for_status()
words = response.text
words = set([word.lower() for word in words.splitlines()])
descriptions = random.sample(words, 100)

multi_checkbox_widget(descriptions)

Hey! @pbugnion
I don't know if it is too late, but I think there is a simple way to improve the search algorithm. It would be to rewrite the close_matches
definition as it follows:
close_matches = sorted(list(filter(lambda x: search_input in x, descriptions)))
With that code you manage to extract all the words that contain the search_input, and besides, words are showed in alphabetical order.
I hope it helps.