Add air pollution dataset to Area page

This change includes an addition of a filter, which allows for rendering
of subscript written in shorthand
(https://pages.uoregon.edu/ncp/Courses/MathInPlainTextEmail.html).

Currently, this new filter only works if there is only one instance of
subscript, and that it's at the end of the string.

hub/management/commands/import_air_quality_data.py

@@ -34,34 +34,34 @@ class Command(BaseCommand):
     }
 
     in_files = {
-        "pm__10": {
-            "pollutant": "PM_{10}",
+        "pm_10": {
+            "pollutant": "PM10",
             "metric": "Annual mean",
             "header_label": "pm102021g",
             "comments": "Gravimetric units",
             "csv_link": "https://uk-air.defra.gov.uk/datastore/pcm/mappm102021g.csv",
         },
-        "pm__2_5": {
-            "pollutant": "PM_{2.5}",
+        "pm_2_5": {
+            "pollutant": "PM2.5",
             "metric": "Annual mean",
             "header_label": "pm252021g",
             "csv_link": "https://uk-air.defra.gov.uk/datastore/pcm/mappm252021g.csv",
         },
-        "no__2": {
-            "pollutant": "NO_2",
+        "no_2": {
+            "pollutant": "NO2",
             "metric": "Annual mean",
             "header_label": "no22021",
             "csv_link": "https://uk-air.defra.gov.uk/datastore/pcm/mapno22021.csv",
         },
-        "no__x": {
-            "pollutant": "NO_X",
+        "no_x": {
+            "pollutant": "NOx",
             "metric": "Annual mean",
             "header_label": "nox2021",
             "comments": "µg m\u207B\u00B3 (NO\u2093 as NO\u2082)",
             "csv_link": "https://uk-air.defra.gov.uk/datastore/pcm/mapnox2021.csv",
         },
-        "so__2": {
-            "pollutant": "SO_2",
+        "so_2": {
+            "pollutant": "SO2",
             "metric": "Annual mean",
             "header_label": "so22021",
             "csv_link": "https://uk-air.defra.gov.uk/datastore/pcm/mapso22021.csv",
@@ -70,7 +70,7 @@ class Command(BaseCommand):
             "pollutant": "Ozone",
             "metric": "DGT120",
             "header_label": "dgt12021",
-            "comments": "metric is number of days on which the daily max 8-hr concentration is greater than 120 µg m\u207B\u00B3",
+            "comments": "number of days on which the daily max 8-hr concentration is greater than 120 µg m\u207B\u00B3",
             "csv_link": "https://uk-air.defra.gov.uk/datastore/pcm/mapdgt12021.csv",
         },
         "benzene": {

hub/templates/hub/area/_place_data.html

@@ -82,6 +82,30 @@ <h5>{{ category.name }}</h5>
                       {% endfor %}
                     </body>
                 </table>
+              {% elif category.name == 'Air pollution' %}
+                <table class="table mb-0">
+                    <thead>
+                        <tr>
+                            <th scope="col">Pollutant</th>
+                            <th scope="col">This area</th>
+                            <th scope="col" class="text-muted">UK average</th>
+                        </tr>
+                    </thead>
+                    <tbody>
+                        {% for range in category.data %}
+                        <tr>
+                            <th>
+                                {{ range.label|html_format_dataset_name|safe }}
+                              {% if range.data_type.description %}
+                                <small class="d-block mt-1 fs-8 fw-normal">{{ range.data_type.description|escape }}</small>
+                              {% endif %}
+                            </th>
+                            <td>{{ range.value|floatformat }}%</td>
+                            <td class="text-muted">{{ range.average|floatformat }}%</td>
+                        </tr>
+                        {% endfor %}
+                    </tbody>
+                </table>
               {% else %}
                 {% if category.data.is_number %}
                 <p class="card-text mb-0 display-6 lh-1 text-primary">{{ category.data.value|floatformat }}{% if category.data.is_percentage %}%{% endif %}</p>

hub/templatetags/hub_filters.py

@@ -56,3 +56,16 @@ def pending_account_requests(**kwargs):
         userproperties__email_confirmed=True,
         userproperties__account_confirmed=False,
     ).count()
+
+
+@register.filter
+@stringfilter
+def html_format_dataset_name(value):
+    pollutants = {
+        "PM10": "PM<sub>10</sub>",
+        "PM2.5": "PM<sub>2.5</sub>",
+        "NO2": "NO<sub>2</sub>",
+        "NOx": "NO<sub>X</sub>",
+        "SO2": "SO<sub>2</sub>",
+    }
+    return pollutants.get(value, value)