A snippet from the Kinja data team's implementation of make_response in our subclass of Flask

kinja-service-make-response-snippet.py

# In the default handler for flask, they don't allow None. We however
# allow anything that's json serializable. :)

if not isinstance(rv, self.response_class):
    if isinstance(rv, (bytes, bytearray)):
        # For now, treat bytes as raw data and don't attempt to
        # JSON-serialize
        rv = self.response_class(rv, status=status, headers=headers)
        status = headers = None
    # Try to coerce things that are Responses or wsgi callables already
    elif isinstance(rv, WerkzeugResponse) or callable(rv):
        rv = self.response_class.force_type(rv, request.environ)
    else:
        # If this is gonna be a problem we'll soon find out!
        rv = success(rv)