import webview """ Run asynchronous Javascript code and invoke a callback. """ def callback(result): print(result) def evaluate_js_async(window): window.evaluate_js( """ new Promise((resolve, reject) => { setTimeout(() => { resolve('Whaddup!'); }, 300); }); """, callback) if __name__ == '__main__': window = webview.create_window('Run async Javascript', html='') webview.start(evaluate_js_async, window)