Flask jsonify returns Response. How to provide status code?

Question

I sow a lot of examples where developers have the following expression:

return jsonify(data), 200

Even in my last work project I had the same expression, but now, when I'm trying to write my new project, I catch the following error:

TypeError: Object of type Response is not JSON serializable

If I return only the result of jsonify(), it works but returns the 200 status code. I want to control the code. It doesn't work with flask_restful.Resource.

Seems like jsonify() returns Response object. How to fix it?

try it without jsonify(), flask-restful handles this already — c8999c 3f964f64, Apr 11 '22 at 07:12

score 0 · Answer 1 · answered Apr 10 '22 at 22:47

0

Sounds like data is a Response object, and the code is choking when you try to serialize that into JSON. Try return jsonify(data.text), 200.

If that doesn't work, we need more code to diagnose this.

answered Apr 10 '22 at 22:47

papillontrail

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6

`data` it's example. If we pass types that JSON supports, result will be the same. – Dzianis Talkachou Apr 11 '22 at 00:12

score 0 · Answer 2 · answered Apr 11 '22 at 07:32

0

flask-restful uses jsonify already.

if you use jsonify with flask-restful, it tries to jsonify a response twice.

simply do this:

return data, 200

answered Apr 11 '22 at 07:32

c8999c 3f964f64

1,430
1
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It won't work with other objects like `datetime.date` I found a solution. I wrapped it in `make_response`. Now it looks `make_response(jsonify(data), 200))` – Dzianis Talkachou Apr 11 '22 at 14:47
turning the data to a json-compatible format is not the issue of this question, but I'm glad you found a way to make it work – c8999c 3f964f64 Apr 11 '22 at 15:06
it will be nice if you provide your ways, I want to find the better one – Dzianis Talkachou Apr 11 '22 at 18:25
well you can simply turn the date object into a string by calling str(date), but like I said, that has nothing to do with this question. – c8999c 3f964f64 Apr 12 '22 at 10:04

score 0 · Answer 3 · answered Oct 17 '22 at 17:26

I was getting the same error, and ended up applying Dzianis Talkachou's workaround to prevent it:

Wrapping the jsonify response in a make_response will do the trick.

from flask import jsonify, make_response
...
return make_response(jsonify(your_data), 200)

Flask jsonify returns Response. How to provide status code?

3 Answers3