CODEWITHSUNDEEP
pythonflaskpayload
MANOJ
MANOJ

Reputation: 736

how to validate the keys exists in the payload in a restful api in flask

I have a complex payload being used in the api as below. Is there a way to validate the below keys in the sample payload exists (request data given in POST or PUT)

{
  "adduser": {
    "usergroup": [
      {
        "username": "john",
        "userid": "kk8989",
        "user_contact": 9343454567,
        "manager_name": "sam",
        "manager_contact": 9343454597,
        "env": "dev",
        "partner": {
          "name": "macy",
          "address": "radom address",
          "assets": [
            "iphone",
            "tesla"
          ],
          "profile": {
            "linkedin": "XXXX",
            "facebook": "XXXX"
          },
          "children": [
            {
              "name": "tim",
              "address": "XXXX"
            },
            {
              "name": "tim",
              "address": "XXXX"
            },
            {
              "name": "tim",
              "address": "XXXX"
            }
          ]
        }
      }
    ]
  }
}

How to validate the above repayload before using it in the application.

Upvotes: 0

Views: 2805

Answers (2)

Dmitry Paramonov
Dmitry Paramonov

Reputation: 46

You can try to use attr and cattr packages:

import attr, cattr


@attr.s
class Response:
    name = attr.ib()
    val = attr.ib(type=int, default=5)


d = cattr.structure({'name': 'some name'}, Response)
print('-->', d)

If you remove default value from val attribute, you'll get a TypeError exception. So, it's up to you how to handle absence of keys. Read packages docs anyway.

Upvotes: 1

Shariq
Shariq

Reputation: 506

The input json is treated just like a dict in python, to validate for keys, or values, you can simply work with the dictionary. E.g. to check if it contains 'school' key u can use if 'school' in json_dict:

@app.route('/', methods=["PUT", "POST"])
def new():
    json_dict = request.get_json(force=True)
    if 'school' not in json_dict:
           return 'Error, school not found'

You can also wrap the request.get_json call in a try except for better exception handling.

You can use jsonschema library to validate against your json schema/model. check out this post here describing the validate() function from jsonschema.

http://code.activestate.com/recipes/579135-validate-data-easily-with-json-schema/

Upvotes: 0

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