Create a Pydantic Model from a JSON schema

schema.py

class Schema(BaseModel):
    title: str = "Model"
    type: Any
    properties: Optional[dict[str, Any]]
    required: Optional[list[str]]
    items: Optional['Schema']
    description: Optional[str]

    @validator('type', pre=True)
    def map_type(cls, v):
        mapping = {
            "string": str,
            "number": float,
            "integer": int,
            "boolean": bool,
            "object": dict,
            "array": list,
            "null": type(None),
        }
        return mapping.get(v, Any)

    def to_model(self) -> BaseModel:
        fields = {}
        if self.properties:
            for name, prop in self.properties.items():
                schema = Schema(**prop)
                if schema.type == dict:
                    model = schema.to_model()
                elif schema.type == list and schema.items:
                    if schema.items.type == dict:
                        model = list[schema.items.to_model()]
                    else:
                        model = list[schema.items.type]
                else:
                    model = schema.type
                default = ... if name not in self.required else None
                field = Field(default, description=schema.description)
                fields[name] = (model, field)
        return create_model(self.title, **fields)

Schema.update_forward_refs()

# Note: Doesn't work with `$ref` fields
# 
# with open("schema.json") as f:
#     json_schema = json.load(f)
# schema = Schema(json_schema)
# PydanticModel = schema.to_model()