The situation:

Sending a `decimal.Decimal` in a dwollav2 request body failed unless the optional `simplejson` package happened to be installed , and simplejson wasn't listed as a dependency anywhere. The reporter argued a JSONEncoder subclass handles decimals fine and simplejson offers no benefit on modern Python; a PR was submitted. The maintainer published the fix in dwollav2 v2.3.0, which serializes Decimal values without needing simplejson.

What actually fixes it (verified in the thread):

Fixed in dwollav2 v2.3.0, which the maintainer confirmed was published , Decimal values in request bodies are now serialized without requiring simplejson. Upgrade to v2.3.0+. Source: https://github.com/Dwolla/dwolla-v2-python/issues/55