Unfortunately, I am not experienced enough to contribute a correction myself. But would love if one of the authors could correct it when he/she gets a chance. Thank you.
What version of Boto did you see this under? This changed significantly under Boto 2.13.2 & I'm having trouble reproducing it. How is item being created?
Boto DynamoDB1 had it implemented correctly. However, DynamoDB2 is ignoring the ADD action. i.e.:
When the attribute "field1" already exists (and is of StringSet type), the following code should resolve to an API call with an "Action: ADD":
Unfortunately, I am not experienced enough to contribute a correction myself. But would love if one of the authors could correct it when he/she gets a chance. Thank you.