For Python there's Marshmallow (https://github.com/marshmallow-code/marshmallow https://github.com/marshmallow-code/marshmallow) and Django REST Framework if yo

For Python there's Marshmallow (https://github.com/marshmallow-code/marshmallow https://github.com/marshmallow-code/marshmallow) and Django REST Framework if you're using Django (http://www.django-rest-framework.org/api-guide/serializers/ http://www.django-rest-framework.org/api-guide/serializers/). Both of these work as you described.