Simple example to demonstrate an issue with openapi generator for python. Keep an eye on the relations attribute which is a dict:
...
class User(BaseModel):
name: str = None
address: Address = None
relations: Dict[str, Address] = None
...
Translates into following schema using fastapi openapi json schema generator:
"User": {
"properties": {
"name": {
"type": "string",
"title": "Name"
},
"age": {
"type": "integer",
"title": "Age"
},
"relations": {
"additionalProperties": {
"$ref": "#/components/schemas/Address"
},
"type": "object",
"title": "Relations"
}
},
"type": "object",
"title": "User"
}Which I think is fine according to Openapi spec
But the generated code fails to deserialize an example
@app.get("/")
async def root() -> User:
return {"name": "John", "age": 25, "relations": {"friend": {"street": "123 Main St", "city": "Springfield"},
"family": {"street": "456 Elm St", "city": "Springfield"}}}results in
/home/dzj8fe/ws/fastapi-test/.venv/bin/python /home/dzj8fe/ws/fastapi-test/client.py
The response of DefaultApi->root_get:
'{"name":"John", "age": 25}'
Process finished with exit code 0
The reason is probably the "not" in the the generated deserilization code:
@classmethod
def from_dict(cls, obj: Dict) -> Self:
"""Create an instance of User from a dict"""
if obj is None:
return None
# Why don't we just let handle pydantic the deserialization? The generated code completely ignores the relations
# attribute.
#
# This code works for me
# _obj = cls.model_validate(obj)
# return _obj
#
# The generated code below does not
if not isinstance(obj, dict):
return cls.model_validate(obj)
_obj = cls.model_validate({
"name": obj.get("name"),
"address": Address.from_dict(obj.get("address")) if obj.get("address") is not None else None,
})
return _obj