How to properly handle wrong urlsafe key provided? [duplicate]

Question

I use the following code to get entity based on urlsafe key given:

q_key = ndb.Key(urlsafe=key)
q = q_key.get()
return q

But in case there is no such entity with given urlsafe key, it return ProtocolBufferDecodeError: Unable to merge from string on the first line, when I would expect q to be equal to None. Is there any other correct way to handle such case except of catching ProtocolBufferDecodeError exception?

Lin

catching ProtocolBufferDecodeError and returning None seems fine for me. – Provenience

@DanCornilescu, this question has been asked before in 2015 (when my question as of 2013), ooook :) – Lin

Answer 1

There is an open bug report for it here

The workaround is...

from google.net.proto.ProtocolBuffer import ProtocolBufferDecodeError
try:
   q_key = ndb.Key(urlsafe=key)
   q = q_key.get()
except ProtocolBufferDecodeError:    
   q = None
return q

I'm a little puzzled as to why this isn't a more common complaint yet. Doesn't anyone test their urls with invalid keys?

Jewell

Still nothing for this? I was writing tests today and hit this. In my case previous App Engine projects didn't use a urlsafe key, so that's why I never hit it previously. Still it's kind of odd that there's not a better way to handle this. – Cowage

Answer 2

You can try this

try:
    q_key = ndb.Key(urlsafe=key)
    q = q_key.get()
except ProtocolBufferDecodeError:    
    q = None
return q

Kentiga