Validate JSON data using python

Question

I need to create a function that validates incoming json data and returns a python dict. It should check if all necessary fields are present in a json file and also validate the data types of those fields. I need to use try-catch. Could you provide some kind of snippets or examples that give me answers?

Answer 1

If you haven't check jsonschema library, it can be useful to validate data. JSON Schema is a way to describe the content of JSON. The library just uses the format to make validations based on the given schema.

I made a simple example from basic usage.

import json
from jsonschema import validate

# Describe what kind of json you expect.
schema = {
    "type" : "object",
    "properties" : {
        "description" : {"type" : "string"},
        "status" : {"type" : "boolean"},
        "value_a" : {"type" : "number"},
        "value_b" : {"type" : "number"},
    },
}

# Convert json to python object.
my_json = json.loads('{"description": "Hello world!", "status": true, "value_a": 1, "value_b": 3.14}')

# Validate will raise exception if given json is not
# what is described in schema.
validate(instance=my_json, schema=schema)

# print for debug
print(my_json)