You can simply do this with help of AJAX... Here is a example which calls a python function which prints hello without redirecting or refreshing the page.
In app.py put below code segment.
#rendering the HTML page which has the button
@app.route('/json')
def json():
return render_template('json.html')
#background process happening without any refreshing
@app.route('/background_process_test')
def background_process_test():
print ("Hello")
return ("nothing")
And your json.html page should look like below.
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script type=text/javascript>
$(function() {
$('a#test').on('click', function(e) {
e.preventDefault()
$.getJSON('/background_process_test',
function(data) {
//do nothing
});
return false;
});
});
</script>
//button
<div class='container'>
<h3>Test</h3>
<form>
<a href=# id=test><button class='btn btn-default'>Test</button></a>
</form>
</div>
Here when you press the button Test simple in the console you can see "Hello" is displaying without any refreshing.