Update app.py

app.py

@@ -86,6 +86,8 @@ print(f"Gradio-client version: {gradio_client.__version__}")
 def get_conv_log_filename():
     t = datetime.datetime.now()
     name = os.path.join(LOGDIR, f"{t.year}-{t.month:02d}-{t.day:02d}-user_conv.json")
+    if not os.path.isfile(name):
+        os.makedirs(os.path.dirname(name), exist_ok=True)
     return name
 
 def get_conv_vote_filename():