Python Eve - POST payload containing a list

Question

I am having trouble with the list type in my schemas. Whenever I try to POST, I get a 422 response stating 'must be of list type'. Below is a simple example that produces this problem.

from eve import Eve

people = {
    'schema': {
        'tests': {
            'type': 'list',
            'schema': {
                'type': 'string'
            },
            'required': True,
        }
    },
    'resource_methods': ['GET', 'POST'],
}

settings = {
    'DOMAIN': {
        'people': people
    }
}
app = Eve(settings=settings)

if __name__ == '__main__':
    app.run()

Then when you POST to the people endpoint with the following:

import requests

url = "http://localhost:5000/people"

person = {
    "tests": ['a', 'b'],
}

r = requests.post(url, data=person)
print(r.json())

You get the 422 response. When I debug this, it looks like the Eve application has received the tests parameter as just a string, 'a', rather than the whole list. From what I can see in the Eve tests on GitHub, this seems to be the right way to make the request, so I can only assume I'm making a mistake in setting up the resource/schema?

Thanks.

Barun Sharma · Accepted Answer · 2015-09-08T11:44:43.733

1

If you print request.POST, you would see UnicodeMultiDict([('tests', u'a'), ('tests', u'b')]). Fix to this would be to use json object for your post.

person = json.dumps({
    "tests": ['a', 'b'],
})

r = requests.post(url, json=person)
print(r.json())

Or in your case, you will have to somehow tweak your POST request at API end to get a list as:- request.POST.getall('tests') and then proceed.

Please check using json in POST request. Also while using json, json.dumps may not be required, the dictionary will be jsonified automatically.

edited Sep 08 '15 at 11:44

answered Sep 08 '15 at 11:26

Barun Sharma

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Ah, that works, thanks. I didn't realise there was a `json`argument in requests. I had already tried `data=json.dumps(payload)`, which gives a 400 error. Now looking at the [requests docs](http://www.python-requests.org/en/latest/user/quickstart/#more-complicated-post-requests) I thought they would be equivalent. – Andrew Walker Sep 08 '15 at 11:40
Probably I should add this link to the answer. – Barun Sharma Sep 08 '15 at 11:42
2

I found that the reason `json=person` works where `data=json.dumps(person)` doesn't is because the json keyword argument also changes the request header to `application/json`, where the manual dump doesn't. – Andrew Walker Sep 08 '15 at 12:42
@AndrewWalker Ok. Thanks. I didn't knew this. – Barun Sharma Sep 08 '15 at 13:41

Python Eve - POST payload containing a list

1 Answers1