fix left pad for some edge cases

app.py

@@ -100,10 +100,11 @@ def retrieve_results(selected_dataset, selected_sequence, selected_models, selec
                 pad_txt_str = ",pad={}:{}:0:{}:white".format(w+padding*2, h+font_size+padding*4, pad_height)
                 text_str = get_text_str(pad_height, w, cur_model['display_name'], font_size)
                 pad_txt_str = pad_txt_str + "," + text_str
-            elif row_idx > 0 and col_idx == 0:
-                pad_txt_str = ",pad={}:ih:{}:0:white".format(w + left_pad + padding*2, left_pad)
-                text_str = get_text_str("h", left_pad, model_viz[row_idx]['display_name'], font_size)
-                pad_txt_str = pad_txt_str + "," + text_str
+            elif col_idx == 0:
+                pad_txt_str = ",pad={}:ih:{}:0:white".format(w + left_pad + padding * 2, left_pad)
+                if len(model_viz) > row_idx > 0:
+                    text_str = get_text_str("h", left_pad, model_viz[row_idx]['display_name'], font_size)
+                    pad_txt_str = pad_txt_str + "," + text_str
             else:
                 pad_txt_str = ""