Flask Restful accept a list in a post request

Question

I am using Flask Restful for my server API and am posting to the server a dictionary where one of the values is a list of dictionary's.

parser.add_argument('products_in_basket', type=list)
def post(self, user_id):
   args = parser.parse_args()
   print request.data
   print args['my_list']

The problem I have is args['my_list'] is only returning the first element of the list. Whereas I can see all list from request.data.

This is request.data

{"address_id":1,"my_list":[{"size":12,"colour":"red","id":34219,"quantity":1},{"size":10,"colour":"red","id":12219,"quantity":2},{"size":8,"colour":"red","id":5214,"quantity":3}],"payment_card_id":1}

This is args['my_list']

[u'colour', u'quantity', u'id', u'size']

Where am I going wrong?

so fetch it from request.data instead – Dan Sep 24 '15 at 21:24 — Dan, Sep 24 '15 at 21:24

siegerts · Accepted Answer · 2018-04-16T16:00:20.107

12

What are your parser add_argument options? Is products_in_basket an actual key to the data that is requested? Or are you trying to provide an arbitrary name and/or rename the dict?

Take a look at Multiple Values & Lists from the Request Parsing documentation.

You may want to be doing something like this instead...

parser = reqparse.RequestParser()
parser.add_argument('my_list', action='append')

edited Apr 16 '18 at 16:00

answered Sep 25 '15 at 13:15

siegerts

461
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11

Thank you, action='append' was the solution :) – Sep 26 '15 at 10:21
Can you please update the link provided? It shows permission denied. – Ruthwik Apr 15 '18 at 13:58
Awesome, just what I needed. this works. – hayreenfly Mar 24 '22 at 23:51

score 1 · Answer 2 · answered Sep 25 '15 at 01:20

1

Try accessing the data like this:

for product in args.my_list:
        size = product.get('size')
        etc....

This will allow you to iterate over all the dict objects in the my_list list.

answered Sep 25 '15 at 01:20

Matt Healy

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score 1 · Answer 3 · answered Jul 30 '19 at 22:23

1

You can use the location parameter in the add_argument function. This will specify that you are working with json and it will append the others elements in the list.

parser = reqparse.RequestParser()
parser.add_argument('my_list', location='json')

answered Jul 30 '19 at 22:23

Kofi Nartey

2,529
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This was the solution for me. Without it, if I passed a single value in a list, it would appear like this : [['v','a','l','u','e']] – Samuurai Apr 14 '23 at 18:07

Flask Restful accept a list in a post request

3 Answers3