Using Flask in python 2.7 to resolve the CORS issue, I need to display the response in ext.js

Question

This is my implementation,

            full_url = url + '?' + params
            req = urllib2.Request(full_url, params)
            
            req.add_header('Content-Type', 'application/javascript')
            req.add_header('Access-Control-Allow-Origin','*')
            req.add_header('Accept', 'application/javascript')
            req.add_header('x-lang', 'en')
            req.add_header('x-app-version', '1.2.3')
            req.add_header('x-consumer-key', 'abc')
            req.add_header('x-source', 'web')
            req.add_header('x-device-id', 'abc-2501015753736970469271537365900144030')
            req.add_header('x-signature', signature)
            req.add_header('X-Content-Type-Options', 'nosniff')
            req.add_header('x-request-id', request)
            req.add_header('x-timestamp', timeStamp)

            response = urllib2.urlopen(req)
            result   = response.read()
            result   = result.decode('latin-1')
            respjson = json.loads(result)

            return respjson

Reading the output in ext.js

        var script = document.createElement("script");

        script.setAttribute("src", url);
        script.setAttribute("type", "text/javascript");
        script.setAttribute("id", trans.scriptId);
        document.getElementsByTagName("head")[0].appendChild(script);

Thank you in advance.

Error shows in the browser "was loaded even though its MIME type (“application/json”) is not a valid JavaScript MIME"

[Error in the browser][1]