Refactor to make testing easier

app/broadcast_areas/constants.py

@@ -38,3 +38,25 @@ class CITY_OF_LONDON:
 class BRYHER:
     WD20_CODE = 'E05011090'
     POPULATION = 84
+
+
+def estimate_number_of_smartphones_for_population(population):
+    smartphone_ownership_for_area_by_age_range = {}
+
+    for range, ownership in SMARTPHONE_OWNERSHIP_BY_AGE_RANGE.items():
+        min, max = range
+        smartphone_ownership_for_area_by_age_range[range] = sum(
+            people
+            for age, people in population
+            if min <= age <= max
+        ) * ownership
+
+    total_population = sum(dict(population).values())
+    total_phones = sum(smartphone_ownership_for_area_by_age_range.values())
+
+    print(  # noqa: T001
+        f'    Population:{total_population: 11,.0f}'
+        f'    Phones:{total_phones: 11,.0f}'
+    )
+
+    return total_phones

app/broadcast_areas/create-broadcast-areas-db.py

@@ -13,6 +13,7 @@ from constants import (
     MEDIAN_AGE_RANGE_UK,
     MEDIAN_AGE_UK,
     SMARTPHONE_OWNERSHIP_BY_AGE_RANGE,
+    estimate_number_of_smartphones_for_population,
 )
 from polygons import Polygons
 from repo import BroadcastAreasRepository
@@ -79,27 +80,10 @@ def estimate_number_of_smartphones_in_area(country_or_ward_code):
     if country_or_ward_code not in area_to_population_mapping:
         raise ValueError(f'No population data for {country_or_ward_code}')
 
-    population = area_to_population_mapping[country_or_ward_code]
+    return estimate_number_of_smartphones_for_population(
-    smartphone_ownership_for_area_by_age_range = {}
+        area_to_population_mapping[country_or_ward_code]
-
-    for range, ownership in SMARTPHONE_OWNERSHIP_BY_AGE_RANGE.items():
-        min, max = range
-        smartphone_ownership_for_area_by_age_range[range] = sum(
-            people
-            for age, people in population
-            if min <= age <= max
-        ) * ownership
-
-    total_population = sum(dict(population).values())
-    total_phones = sum(smartphone_ownership_for_area_by_age_range.values())
-
-    print(  # noqa: T001
-        f'    Population:{total_population: 11,.0f}'
-        f'    Phones:{total_phones: 11,.0f}'
     )
 
-    return total_phones
-
 
 ctry19_filepath = source_files_path / "Countries.geojson"