JSON Schema validator

example.py

# example.py
from jsonschema import FormatChecker
from .jsonschema_validator import get_validator


USER_SCHEMA = {
	"$schema":"http://json-schema.org/draft-07/schema#",
	"title":"User",
	"type" : "object",
	"properties" : {
		"email": {
			"type" : "string",
			"format": "email"
		},
		"pwd": {
			"type" : "string",
			"minLength": 2,
			"maxLength": 64
		},
		"age": {
			"type" : "integer",
			"minimum": 18,
			"maximum": 50
		}
	},
	"additionalProperties": False,
	"required": ["email", "pwd", "age"]
}


# Create a validator function for a given schema
validate = get_validator(USER_SCHEMA)

# Pass data to the validator function
errors = validate(
		data={"email": "test@gmail.com", "pwd": "password"},
		format_checker=FormatChecker()
	)

if errors:
	print(errors)
	# [
	# 	{
	# 		'message': "'test' is not a 'email'",
	# 		'key': 'email',
	# 		'context': 'format'
	# 	},
	# 	{
	# 		'message': "'age' is a required property",
	# 		'key': 'age',
	# 		'context': 'required'
	# 	}
	# ]

validator.py

# validator.py
import re
from jsonschema import (
	exceptions,
	Draft7Validator,
	FormatChecker
)


def get_validator(schema):
	def validator(*args, **kwargs):
		def _get_error(err):
			return {
				"message": err.message,
				"key": get_offending_key(err),
				"context": err.validator
			}

		try:
			v = Draft7Validator(
				schema,
				format_checker=kwargs.get("format_checker")
			)
			errors = sorted(v.iter_errors(kwargs.get("data")), key=str)

			return list(
				map(lambda err: _get_error(err), errors)
			) if len(errors) else None
		except exceptions.ValidationError as v:
			raise v

	return validator


def get_offending_key(err):
	return (re.findall(r"\'.*?\'", err.message)[0].replace("'", "") or "") \
		if not len(err.path) else "".join(
			map(
				lambda part: str("[{}]".format(part) if isinstance(part, int) else part),
				err.path
			)
		)