Brython と iFlyChat をロードしていますが、iFlyChat スクリプトのコメントを外すと Brython が機能しません。私はあらゆる種類の非同期の組み合わせを試しましたが、もっと基本的なものがあるようです。
ここに JSFiddle と以下のコード:
https://jsfiddle.net/tutmoses/c09dhbrq/
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Title</title>
<!-- BRYTHON -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/brython/3.8.8/brython.js" integrity="sha256-rA89wPrTJJQFWJaZveKW8jpdmC3t5F9rRkPyBjz8G04=" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/brython/3.8.8/brython_stdlib.js" integrity="sha256-Gnrw9tIjrsXcZSCh/wos5Jrpn0bNVNFJuNJI9d71TDs=" crossorigin="anonymous"></script>
<!-- IFLYCHAT
<script>
console.log("init iflychat plugin");
var iflychat_app_id="1c0d1abc-4864-4608-acb7-6cdbfab07ce2";
var iflychat_external_cdn_host="cdn.iflychat.com",iflychat_bundle=document.createElement("SCRIPT");iflychat_bundle.src="//"+iflychat_external_cdn_host+"/js/iflychat-v2.min.js?app_id="+iflychat_app_id,iflychat_bundle.async="async",document.body.appendChild(iflychat_bundle);var iflychat_popup=document.createElement("DIV");iflychat_popup.className="iflychat-popup",document.body.appendChild(iflychat_popup);
</script> -->
</head>
<body onload="brython()">
<div class="container">
<h2 id="hello"></h2>
<button id="alert-btn">Alert & Insert</button>
<input type="text" id="text" placeholder="Enter something">
<span id="output"></span>
</div>
<!-- Alert & DOM insert -->
<script type="text/python" id="script0">
from browser import document, console, alert
def show(e):
console.log(e)
alert('Hello World')
document['hello'] <= 'Hello World'
document['alert-btn'].bind('click', show)
</script>
<!-- Text bind -->
<script type="text/python" id="script1">
from browser import document
def show_text(e):
document['output'].textContent = e.target.value;
document['text'].bind('input', show_text)
</script>
</body>
</html>