Add docstring to function (#2051)

* added docstring to function

* rename year -> financial_year

app/main/views/dashboard.py

@@ -390,7 +390,7 @@ def aggregate_by_type(data, daily_data):
     bounce_rate_data = get_bounce_rate_data_from_redis(service_id)
 
     # get annual data from fact table (all data this year except today)
-    annual_data = service_api_client.get_monthly_notification_stats(service_id, year=get_current_financial_year())
+    annual_data = service_api_client.get_monthly_notification_stats(service_id, get_current_financial_year())
     annual_data = aggregate_by_type(annual_data, dashboard_totals_daily[0])
 
     return {

app/notify_client/service_api_client.py

@@ -382,11 +382,28 @@ def get_service_history(self, service_id):
 
     # TODO: cache this once the backend is updated to exlude data from the current day
     # @flask_cache.memoize(timeout=_seconds_until_midnight())
-    def get_monthly_notification_stats(self, service_id, year):
+    def get_monthly_notification_stats(self, service_id: str, financial_year: int):
+        """
+        Retrieve monthly notification statistics for a specific service and year.
+
+        Args:
+            service_id (str): UUID of the service to get statistics for
+            financial_year (int): The financial year to fetch statistics for (YYYY format)
+
+        Returns:
+            dict: Monthly notification statistics like this:
+            {
+                'data': {
+                    '2024-04': {'sms': {}, 'email': {}, 'letter': {}},
+                    '2024-05': {'sms': {}, 'email': {'technical-failure': 1, 'sending': 26}, 'letter': {}},
+                    ...
+                },
+            }
+        """
         return self.get(
             url="/service/{}/notifications/monthly?year={}".format(
                 service_id,
-                year,
+                financial_year,
             )
         )