How to validate a json structure in Python3

Question

I am using Python3.5 and Django for a web api.When I refer to input, I refer to a HTTP request parameters. I have a parameter where I am expecting a JSON data which I need to validate before processing further.

I have a base json structure that the input has to be in. Example,

{
  "error": "bool",
  "data": [
      {
        "name": "string",
        "age": "number"
      },
      {
        "name": "string",
        "age": "number"
      },
      ...
    ]
}

The above JSON represents the structure that I want my input to be in. The keys are predefined, and the value represents the datatype of that key that I am expecting. I came across a Python library( jsonschema ) that does this validation, but I can't find any documentation where it works with dynamic data. ie the objects inside the JSON array 'data' can be of any number, of course this is the most simple scenario I came up with for explaining the basic requirement. In cases like these, how can I validate my json ?

The solution here didn't help because it's just checking if the json is proper or not based on the Django model. My json has no relation with Django model. Its a simple json structure. It still doesn't tell me how to validate dynamic object

Answer 1

JSON Schema is a specification for validating JSON; jsonschema is just a Python library that implements it. It certainly does allow you to specify that a key can contain any number of elements.

An example of a JSON Schema that validates your code might be:

{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "type": "object",
  "additionalProperties": false,
  "required": [
    "error",
    "data"
  ],
  "properties": {
    "error": {
      "type": "boolean"
    },
    "data": {
      "type": "array",
      "items": {
        "type": "object",
        "additionalProperties": false,
        "properties": {
          "name": {
            "type": "string"
          },
          "age": {
            "type": "integer"
          }
        }
      }
    }
  }
}

See https://spacetelescope.github.io/understanding-json-schema/ for a good overview

Answer 2

Take a look into the documentation of Python's JSON API . I believe json.tool is what you're looking for, however there are a couple of other ways to validate JSON using that API.