Resolve "[Bug] Program crashes when no built area is present within a district"

Closes #5 (closed)

\approve @tara @shinde

exposureinitializer/exposureinitializer.py

@@ -223,9 +223,12 @@ class ExposureInitializer:
         # in subquery `SumQuery` to estimate the sum of the built-area and the cross-joined
         # query retrieving the built-area size per tile to compute the built-area proportion.
         if isinstance(self.exposure_db, SpatiaLiteExposure):
-            where_clause = "WHERE built_area_size IS NOT NULL"
+            where_clause = "WHERE built_area_size IS NOT NULL AND built_area_size > 0"
         else:
-            where_clause = "WHERE A.geometry && B.border AND built_area_size IS NOT NULL"
+            where_clause = """
+                WHERE A.geometry && B.border AND built_area_size IS NOT NULL
+                AND built_area_size > 0
+                """
         sql_statement = f"""
             WITH T AS
             (
@@ -263,17 +266,15 @@ class ExposureInitializer:
 
             # Add the respective assets by proportion of built area to `AssetReference`
             for taxonomy_id, value in asset_dict.items():
-                sql_statement = """
+                sql_statement = f"""
                     INSERT INTO AssetReference
                     (entity_id, taxonomy_id, number, structural, night)
-                    VALUES (%d, %d, %f, %f, %f)
-                    """ % (
-                    entity_id,
-                    int(taxonomy_id),  # taxonomy_id
-                    float(value["number"]) * proportion,  # number
-                    float(value["structural"]) * proportion,  # structural
-                    float(value["night"]) * proportion,  # night
-                )
+                    VALUES ({entity_id},
+                            {int(taxonomy_id)},
+                            {float(value["number"]) * proportion},
+                            {float(value["structural"]) * proportion},
+                            {float(value["night"]) * proportion})
+                    """
                 self.exposure_db.cursor.execute(sql_statement)
         self.exposure_db.connection.commit()
 
@@ -347,21 +348,19 @@ class ExposureInitializer:
             sum_number += value["number"]
         # Assign the country-average asset distribution to the country assets
         for taxonomy_id, value in country_asset_dict.items():
-            sql_statement = """
+            sql_statement = f"""
                 INSERT INTO AssetCountry
                 (country_iso_code, taxonomy_id, number, number_normalized, structural,
                  structural_normalized, night, night_normalized)
-                VALUES ('%s', %d, %f, %f, %f, %f, %f, %f)
-                """ % (
-                country_iso_code,
-                int(taxonomy_id),
-                float(value["number"]),
-                float(value["number"]) / sum_number,
-                float(value["structural"]),
-                float(value["structural"]) / sum_number,
-                float(value["night"]),
-                float(value["night"]) / sum_number,
-            )
+                VALUES ('{country_iso_code}',
+                        {int(taxonomy_id)},
+                        {float(value["number"])},
+                        {float(value["number"]) / sum_number},
+                        {float(value["structural"])},
+                        {float(value["structural"]) / sum_number},
+                        {float(value["night"])},
+                        {float(value["night"]) / sum_number})
+                """
             self.exposure_db.cursor.execute(sql_statement)
         self.exposure_db.connection.commit()
 
@@ -408,6 +407,7 @@ class ExposureInitializer:
                     FROM {self.exposure_db.tile_view}
                     WHERE (country_iso_code = '{country_iso_code}')
                         AND (built_area_size IS NOT NULL)
+                        AND (built_area_size > 0)
                 ) AS A
                 LEFT JOIN EntityReference AS E
                 ON E.quadkey = A.quadkey