Covid Dashboard: Change in Stats REST API none return value causes crash

[edumorlom]

There was a breaking change to the return type of the Stats REST APIs that caused the server to crash with TypeError exception when trying to retrieve "data" from "None".

When making a request using the stats data commons REST APIs, if there was no data to return for a given dcid, it would drop the dcid from the response. Now, instead, it will return dcid->None, which caused issues when trying to read the data value.

Example of return type for dcid without a value:

Exception Message:

data = response[dcid]['data']
TypeError: 'NoneType' object is not subscriptable

[edumorlom]

The workaround is to try to retrieve the data, and if it fails due to TypeError exception because there is no data, continue to the next iteration.

for dcid in response:
   try:
      data = response[dcid]['data']
      data_holder[dcid] = data
   except TypeError:
         continue

[shifucun]

It is helpful to handle null/empty data in key value retrieval. In this case, you can do:

for dcid in response:
if response[dcid] and 'data' in response[dcid]:
xxx
else:
logging.error('missing data ...')