CODEWITHSUNDEEP
pythoncode-generationpydanticgenson
shaik moeed
shaik moeed

Reputation: 5785

How to fix - UserWarning: Pydantic serializer warnings in Pydantic V2?

Using datamodel-codegen command with JSON data as input type and generating Pydantic schema as output, during this process I was seeing warnings.

What is the meaning of these warnings and how to fix them? What kind of issues it can create(or why this is a warning)?

UserWarning:

Expected `Union[list[definition-ref], definition-ref, bool]` but got `JsonSchemaObject` - serialized value may not be as expected
Expected `Union[definition-ref, bool]` but got `JsonSchemaObject` - serialized value may not be as expected
Expected `Union[definition-ref, bool]` but got `JsonSchemaObject` - serialized value may not be as expected
Expected `Union[definition-ref, bool]` but got `JsonSchemaObject` - serialized value may not be as expected
  return self.__pydantic_serializer__.to_python(

To reproduce:

pets.json

{
  "pets": [
    {
      "name": "dog",
      "age": 2
    },
    {
      "name": "cat",
      "age": 1
    },
    {
      "name": "snake",
      "age": 3,
      "nickname": "python"
    }
  ],
  "status": 200
}

Command:

datamodel-codegen  --input pets.json --input-file-type json --output model.py

Versions:

python - 3.11.4
pydantic==2.1.1
datamodel-code-generator==0.21.4
genson==1.2.2

Upvotes: 6

Views: 13532

Answers (2)

bemaxradio
bemaxradio

Reputation: 1

In my case updating pydantic and datamodel-code-generator helped

pip install -U pydantic datamodel-code-generator

For python 3.10

Upvotes: 0

Oriol
Oriol

Reputation: 1

I had a similar issue when there are cyclic nested models. If that is your problem, you need to call:

YourSchemaContainingNestedModel.model_rebuild()

after declaring the model.

Not sure if this is your case, though, since I cannot see the schemas you are using.

Upvotes: 0

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