♻️ Minor fixes to the survey metrics

- use `.get` to check whether this is an enketo survey so that it works for
  older deployments that predate the `survey_info` functionality as well. This
  has no functional difference since, if there is no `survey_info`, this is not
  a survey. But we get a better exception and avoid confusion later.
- improve error handling for survey_responses, by splitting the attribute and
  name errors from the more complex errors

viz_scripts/survey_metrics.ipynb

@@ -72,7 +72,7 @@
    "outputs": [],
    "source": [
     "# Do not run this notebook at all unless it is for a survey configuration; nbclient will run up through this cell\n",
-    "if not survey_info['trip-labels'] == 'ENKETO':\n",
+    "if not survey_info.get('trip-labels', None) == 'ENKETO':\n",
     "    ipython = get_ipython()\n",
     "    ipython._showtraceback = scaffolding.no_traceback_handler\n",
     "    raise Exception(\"The plots in this notebook are only relevant to deployments with trip-level surveys\")"

viz_scripts/survey_responses.ipynb

@@ -53,7 +53,7 @@
    "outputs": [],
    "source": [
     "# Do not run this notebook at all unless it is for a survey configuration; nbclient will run up through this cell\n",
-    "if not survey_info['trip-labels'] == 'ENKETO':\n",
+    "if not survey_info.get('trip-labels', None) == 'ENKETO':\n",
     "    ipython = get_ipython()\n",
     "    ipython._showtraceback = scaffolding.no_traceback_handler\n",
     "    raise Exception(\"The plots in this notebook are only relevant to deployments with trip-level surveys\")"
@@ -372,10 +372,14 @@
     "            \n",
     "            plot_and_text_stacked_bar_chart(plot_df, \"Responses\", ax, text_results, get_survey_colors(list(plot_df.index.values) ,color_map), debug_df)\n",
     "            set_title_and_save(fig, text_results, plot_title, filename)\n",
-    "\n",
-    "        except:\n",
+    "        except (AttributeError, KeyError, pd.errors.UndefinedVariableError) as e:\n",
+    "            plt.clf()\n",
     "            generate_missing_plot(plot_title_no_quality, debug_df, filename)\n",
-    "            alt_text = store_alt_text_missing(debug_df, filename, plot_title_no_quality)"
+    "            alt_text = store_alt_text_missing(debug_df, filename, plot_title_no_quality)        \n",
+    "            alt_html = store_alt_html_missing(debug_df, filename, plot_title_no_quality)\n",
+    "        except Exception as e:\n",
+    "            fig, ax = plt.subplots()\n",
+    "            plot_and_text_error(e, ax, filename)"
    ]
   }
  ],