validate a json schema considering all fields required regardless of what's in the 'required' list

jsonschema_all_required.py

from jsonschema import Draft4Validator
from jsonschema.exceptions import ValidationError

myschema = {
    'type': 'object',
    'properties': {
        'required_property': {
            'type': 'string',
        },
        'optional_property': {
            'type': 'string',
        }
    },
    'required': ['required_property'],
    'additionalProperties': False
}


first_instance = {
    'required_property': 'somestring',
    'optional_property': 'someotherstring'
}

second_instance = {
    'required_property': 'somestring',
}


class AllRequiredValidator(Draft4Validator):
    def __init__(self, schema):
        super(AllRequiredValidator, self).__init__(schema)
        self.VALIDATORS['required'] = self.required

    @staticmethod
    def required(validator, required, instance, schema):
        if not validator.is_type(instance, 'object'):
            return

        all_properties = schema.get('properties', {})
        for property in all_properties:
            if property not in instance:
                raise ValidationError("Evaluating in ALL_REQUIRED mode: '{}' must be present".format(property))


validator = AllRequiredValidator(myschema)

print 'validation of full instance: ', validator.validate(first_instance, myschema)
print 'validation of missing field: ', validator.validate(second_instance, myschema)