This simple Python project illustrates how to use Flask to create interactive Altair plots. The motivation is that even though Altair provides a lot of interactivity features, it might be useful to create own HTML widgets, too.
A change in the plot can be invoked by either Show button or any of the sliders, although it's clear that it might not be necessary in real applications. For the sake of brevity, there are no CSS.
Clone the project and then install the requirements. It is possible to do it within a virtual environment as follows:
python3 -m venv venv
source venv/bin/activate
pip install -r requirements.txtThe application was tested with Python 3.8.
Execute
FLASK_APP=altair_flask_demo/main.py flask runand then open http://127.0.0.1:5000/ in your web browser.