Update app.py

app.py

@@ -4,7 +4,7 @@ import urllib
 def display_survey(survey_id):
     base_url = "https://app.surveystack.io/api/submissions"
     params = {'survey': survey_id}
-    survey_url = base_url + urllib.urlencode(params)
+    survey_url = "{}{}".format(base_url, urllib.parse.urlencode(params))
     
     iframe_html = f'<iframe src="{survey_url}" width="100%" height="600px"></iframe>'
     return iframe_html