brython
Implementation of Python 3 running in the browser
...Since version 3.8.0, Brython implements the Python version of the same major/minor version number. It includes libraries to interact with DOM elements and events, and with existing Javascript libraries such as jQuery, D3, Highcharts, Raphael etc. It supports the latest specs of HTML5/CSS3, and can use CSS Frameworks like Bootstrap3, LESS, SASS etc. The most simple way to get started, without anything to install, is to use the distribution available online through jsDelivr.