fix(example): Inform user if no data yet

Author: tyeth

examples/basics/digital_out.py

@@ -28,9 +28,9 @@
 # Create an instance of the REST client.
 aio = Client(ADAFRUIT_IO_USERNAME, ADAFRUIT_IO_KEY)
 
-try: # if we have a 'digital' feed
-    digital = aio.feeds('digital')
-except RequestError: # create a digital feed
+try:  # if we have a 'digital' feed
+    digital = aio.feeds("digital")
+except RequestError:  # create a digital feed
     feed = Feed(name="digital")
     digital = aio.create_feed(feed)
 
@@ -40,16 +40,29 @@
 
 
 while True:
+    TIME_TO_SLEEP = 0.5
     try:
         data = aio.receive(digital.key)
-    except RequestError as re:
-        pass  # feed with no data will return 404
-    if int(data.value) == 1:
-        print('received <- ON\n')
-    elif int(data.value) == 0:
-        print('received <- OFF\n')
-
-    # set the LED to the feed value
-    led.value = int(data.value)
+        if int(data.value) == 1:
+            print("received <- ON\n")
+        elif int(data.value) == 0:
+            print("received <- OFF\n")
+
+        # set the LED to the feed value
+        led.value = int(data.value)
+
+    except RequestError as e:
+        # feed with no data will return 404
+        error_message = getattr(e, "message", str(e))
+        if getattr(e, "status_code", None) == 404 and "not found" in error_message.lower():
+            print(
+                "Feed 'digital' has no data yet!\n"
+                + "Try adding some at https://io.adafruit.com/{0}/feeds/digital".format(
+                    ADAFRUIT_IO_USERNAME
+                )
+            )
+            TIME_TO_SLEEP = 5
+        else:
+            print("Error retrieving data from feed 'digital': {0}".format(e))
     # timeout so we dont flood adafruit-io with requests
-    time.sleep(0.5)
+    time.sleep(TIME_TO_SLEEP)