Pydantic model dynamic field type-CodePudding

In my current FastAPI project work, I have following scenario

from pydantic import BaseModel

class DataSchemaModel(BaseModel):
    Data: Any

I will know the Data:(Any) type during runtime(might be some other class type), not during declaration. Is it possible to implement this in pydantic model? Any suggestion is much appreciated.

CodePudding user response：

You can use pydantic's create_model to create the class with a parameterized type. Simple example to create a class where Data is typed as int:

from pydantic import create_model

# define your type or class here
data_type = int

DataSchemaModel = create_model('DataSchemaModel', Data=(data_type, ...))

# testing: works
DataSchemaModel(Data=42)

# testing: fails with 
# pydantic.error_wrappers.ValidationError: 1 validation error for  DataSchemaModel
# Data
#  value is not a valid integer (type=type_error.integer)
DataSchemaModel(Data=[1, 2])