Update app.py

app.py

@@ -86,7 +86,11 @@ sample_data = response["data"][0]
 
 
 
-user_num = len(sample_data['gpus'].items())
+user_num = 0
+
+if len(sample_data['gpus'])>0:
+    user_num= len(sample_data['gpus'].items())
+
 total_gpu = sample_data['total']['total']
 used_gpu = sample_data['total']['used']
 timestamp_list = []