How to import library using Brython
You need to include brython_stdlib.js in your html code. So your html should look like this: <html> <head> <script src=”https://stackoverflow.com/questions/40001634/src/Brython3.2.8/brython.js”></script> <script src=”../src/Brython3.2.8/brython_stdlib.js”></script> </head> <body onload=”brython()”> <script type=”text/python”> import sys from browser import document, alert def echo(ev): alert(document[“zone”].value) document[‘mybutton’].bind(‘click’, echo) </script> <input id=”zone”><button id=”mybutton”>click !</button> </body> </html>