Only call OpenWeather API once an hour to avoid rate limits

app.py

@@ -28,6 +28,9 @@
 from psycopg2 import pool
 import database_management as dm
 
+# Utility
+from datetime import datetime, timedelta
+
 import user_settings as us  # JSON header verification, API key, etc.
 
 
@@ -48,6 +51,7 @@
 # Get read and write DB connection for managing database. Initialize DB object.
 writeConn = psycopg2.connect(us.databaseUrl)
 db = dm.AirDatabase(writeConn)
+last_weather_fetch_time = datetime.now()
 
 
 # Add incoming data to DB.
@@ -65,15 +69,23 @@ def insert_data():
         # Add all historical data to DB.
         db.load_historal_data()
 
-    if us.openWeatherApiKey:
-        print('querying weather API')
-        # Make get request to OpenWeather API.
-        weatherResponse = get("https://api.openweathermap.org/data/2.5/onecall?lat={}&lon={}&appid={}&units=imperial&lang={}".format(
-            us.latitude, us.longitude, us.openWeatherApiKey, us.lang))
-        print('got weather API response')
-
-        weatherData = json.loads(weatherResponse.content.decode('utf-8'))
-        db.insert_weather_row_and_forecasts(weatherData)
+    current_time = datetime.now()
+    # Only fetch new weather data if it's been more than an hour since the
+    # last fetch.
+    if current_time < last_weather_fetch_time + timedelta(hours = 1):
+        if us.openWeatherApiKey:
+            print('querying weather API')
+            # Make get request to OpenWeather API.
+            weatherResponse = get("https://api.openweathermap.org/data/2.5/onecall?lat={}&lon={}&appid={}&units=imperial&lang={}".format(
+                us.latitude, us.longitude, us.openWeatherApiKey, us.lang))
+            print('got weather API response')
+
+            weatherData = json.loads(weatherResponse.content.decode('utf-8'))
+            result = db.insert_weather_row_and_forecasts(weatherData)
+
+            if result != 'failed' and db.table_rowcount("weather_data") > 0:
+                global last_weather_fetch_time
+                last_weather_fetch_time = current_time
 
     return 'done'
 

database_management.py

@@ -245,6 +245,33 @@ def table_exists(self, table_name):
             print('checked if {} exists'.format(table_name))
             return self.cur.rowcount != 0
 
+    def table_rowcount(self, table_name):
+        """
+        Return the number of rows in the table.
+
+        Args:
+            table_name: str
+
+        Returns:
+            integer
+        """
+        records = None
+
+        try:
+            self.cur.execute(
+                "SELECT TABLE_ROWS FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = {} ".format(table_name))
+        except psycopg2.ProgrammingError as e:
+            print(e)
+            self.conn.rollback()
+        else:
+            # Format data.
+            try:
+                records = cur.fetchall()
+                return records.TABLE_ROWS[0]
+            except psycopg2.ProgrammingError:
+                print('no data in selected timeframe')
+                return None
+
     def del_row(self, data):
         """
         Remove an observation from the air database.
@@ -368,6 +395,7 @@ def insert_weather_row_and_forecasts(self, data):
         except (psycopg2.ProgrammingError, psycopg2.errors.UniqueViolation, KeyError) as e:
             print('failed: ', e)
             self.conn.rollback()
+            return 'failed'
         else:
             self.conn.commit()