JSFiddle - React, Tailwind, and code Playground

HTML

<div id="loading">
    <p><img src="./images/loading.gif" /> Please Wait</p>
</div>

<form action="./cgi-bin/my_script.py" method="post" enctype="multipart/form-data" name="fname">
    <input type="submit" id="submit" value="Submit" />
</form>

CSS

#loading { display:none; }

JavaScript

$(document).ready(function() {
    $("form").submit(function() {
        showLoading();
        $('#content').load('./cgi-bin/my_script.py', null, showResponse);
    });

    function showResponse() {
        hideLoading();
    }

    function showLoading() {
        $("#loading").show();
    }

    function hideLoading() {
        $("#loading").hide();
    }
});