Marshmallow is really useful. +1.  If you like Marshmallow, you might also like Pilo (<a href="https:&#x2F;&#x2F;github.com&#x2F;eventbrite&#x2F;pilo" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;eventbrite&#x2F;pilo</a>), which solves similar problems.  Marshmallow excels at ORM object serialization. Pilo is really good at parsing JSON into Python objects, and has several features to support this, such as polymorphic downcasting and programmable parsing via hooks.  Marshmallow is also very good at parsing&#x2F;validating Python dictionaries, but in my experience, Marshmallow&#x27;s API is more focused on serializing objects into dictionaries so that you can call json.dumps on the output dictionary.