Django: outputting JSON, not OrderedDict - django

Question

I have a strange problem.
I have an API built with the Django REST framework.
I'm making a call and getting the following JSON back:
{
"success": true,
"result": {
"user_type": "ta",
"email": "myemail#gmail.com",
"first_name": "John",
"last_name": "Smith",
"mobile_phone": "555-555-5555",
"id": "0f165a85-2da6-4dcb-97cb-bf04900a942b"
}
}
I've tried to add a logging middleware when I'm trying to get the same output from response.data and writing int into a text field in my database.
For the very same request response.data is this: (and this gets written into my db, instead of the desired JSON string from above):
{'success': True, 'result': OrderedDict([('user_type', 'ta'), ('email', 'myemail#gmail.com'), ('first_name', 'John'), ('last_name', 'Smith'), ('mobile_phone', '555-555-5555'), ('id', UUID('0f165a85-2da6-4dcb-97cb-bf04900a942b'))])}
Why is that? How can I get get rid of that OrderedDict and get a perfect JSON string from response.data?
Please note: json.dumps doesn't work. I'm getting TypeError: Object of type 'UUID' is not JSON serializable. My entire ID system in the models is based on UUIDs. However, my Django REST framework is capable of serializing it just fine in the above example... how is that done?

Answer 1

You are hitting this problem because you're trying to dump the internal representation using json.dumps, which doesn't know how to handle UUID objects.
I can see two options - one, teach dumps how to serialize a UUID. This can be done by subclassing JSONDecoder, e.g. this SO answer.
However, DRF already knows how to serialize these fields. Poking around in the debugger, it looks like the response text is stashed in response.rendered_content. I'd check if that's populated by the time your middleware is run.

Answer 2

json.dumps(log_data, indent=2)
this can format your dict to the str you want.
eg:
# save log_data in some way
log_data = {
"success": True,
"result": {
"user_type": "ta",
"email": "myemail#gmail.com",
"first_name": "John",
"last_name": "Smith",
"mobile_phone": "555-555-5555",
"id": "0f165a85-2da6-4dcb-97cb-bf04900a942b"
}
}
logger.info(json.dumps(log_data, indent=2))
print(json.dumps(log_data, indent=2), type(json.dumps(log_data, indent=2)))
logger save to django.log like:

Answer 3

I managed to find this posted solution.
https://arthurpemberton.com/2015/04/fixing-uuid-is-not-json-serializable
I added the code to my models and now I do not get TypeError: Object of type 'UUID' is not JSON serializable when I serialize my UUID fields. This allowed me to call json.dumps on my response.data and serialize it to text perfectly.