如何从python dict生成json schema

import json
from jsonschema import Draft7Validator, validators

def from_dict_to_schema(data):
    def extend_with_default(validator_class):
        validate_properties = validator_class.VALIDATORS["properties"]

        def set_defaults(validator, properties, instance, schema):
            for error in validate_properties(
                validator, properties, instance, schema
            ):
                yield error

            for property, subschema in properties.items():
                if "default" in subschema:
                    instance.setdefault(property, subschema["default"])

        return validators.extend(
            validator_class, {"properties": set_defaults}
        )

    MyValidator = extend_with_default(Draft7Validator)

    def from_dict(validator, dct, instance, schema):
        if not isinstance(instance, dict):
            yield validators.ValidationError("Instance is not a dictionary")
            return

        for k, v in dct.items():
            if isinstance(v, dict):
                if "type" not in v:
                    v["type"] = "object"
                yield from_dict(validator, v, instance.get(k, {}), schema)
            else:
                instance[k] = v

    schema = {}
    validator = MyValidator(schema)
    validator.validate(data)

    for error in from_dict(validator, data, {}, schema):
        raise validators.ValidationError(error)

    return schema

data = {
    "name": "John Doe",
    "age": 30,
    "email": "johndoe@example.com"
}

schema = from_dict_to_schema(data)