Receiving a feed with no data points raises 404 RequestError

[brentru]

Calling client.receive on a newly created feed with no data points raises a 404 if no data exists on the feed.

Update the library to not error on that call with a 404, and instead return a None value or a Data type which sets the value as None:

Data(created_epoch=None, created_at='2020-07-10T13:52:52Z', updated_at='2020-07-10T13:52:52Z', value='None', completed_at=None, feed_id=1157950, expiration='1599573172.0', position=None, id='0EG0X017NKRDS5527E3YXN0VP4', lat=None, lon=None, ele=None)

Example code

# Create an instance of the REST client.
aio = Client(ADAFRUIT_IO_USERNAME, ADAFRUIT_IO_KEY)
try: # i we have a 'digital' feed
    digital = aio.feeds('digital')
except RequestError: # create a digital feed
    feed = Feed(name="digital")
    digital = aio.create_feed(feed)
while True:
    print(digital)
    data = aio.receive(digital.key)
    time.sleep(0.5)

Output

Traceback (most recent call last):
File "/home/pi/Documents/digital_out.py", line 45, in <module>
data = aio.receive(digital.key)
File "/home/pi/.local/lib/python3.7/site-packages/Adafruit_IO/client.py", line 216, in receive
return Data.from_dict(self._get(path))
File "/home/pi/.local/lib/python3.7/site-packages/Adafruit_IO/client.py", line 118, in _get
self._handle_error(response)
File "/home/pi/.local/lib/python3.7/site-packages/Adafruit_IO/client.py", line 108, in _handle_error
raise RequestError(response)
Adafruit_IO.errors.RequestError: Adafruit IO request failed: 404 Not Found - not found - API documentation can be found at https://io.adafruit.com/api/docs

[blacklight]

Not sure if this library is still maintained, but this is a core breaking bug that has been open for at least a year. Is there any plan to tackle it or will someone try and fork the library?

[RobisLV]

Can confirm. I am experiencing the same bug.

>>> aio.receive("myfeed") Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/usr/local/lib/python3.7/dist-packages/adafruit_io-2.5.0-py3.7.egg/Adafruit_IO/client.py", line 216, in receive File "/usr/local/lib/python3.7/dist-packages/adafruit_io-2.5.0-py3.7.egg/Adafruit_IO/client.py", line 118, in _get File "/usr/local/lib/python3.7/dist-packages/adafruit_io-2.5.0-py3.7.egg/Adafruit_IO/client.py", line 108, in _handle_error Adafruit_IO.errors.RequestError: Adafruit IO request failed: 404 Not Found - not found - API documentation can be found at https://io.adafruit.com/api/docs

[brunofcat]

the same issue.

[tyeth]

Just spotted this issue, I should have probably fixed it instead of fixing the example in #160 🤦
Added to my list.

[lorennorman]

This error is happening when a feed has no data, yet. The API responds with 404 and a generic "not found" error, leaving the Python client to die without much info.

Just now, the IO team has updated the error messages for some of these data messages. Specifically the method:

aio.receive(feed_key)

will say "This feed has not published any data, yet.", which more clearly explains what is happening to the user.

I believe @tyeth may also want to update the client itself to notice such errors and improve the behavior. It could catch these, emit a warning message, and return None, for example.