setattr does not add extra field to model_extra (i.e. __pydantic_extra__) #6333
Description
Initial Checks
- I confirm that I'm using Pydantic V2 installed directly from the
mainbranch, or equivalent
Description
First off, I may have missed this in the migration guide, so my apologies if I missed this change there.
In Pydantic V1 if extra fields are allowed (extra="allow"), setting a non-field attribute on a model instance (m.extra_field = "extra_value") adds the extra field to __dict__ and thus the extra field is included in dict() and json() outputs. I would not expect in Pydantic V2 that the extra field would be set on __dict__, but instead __pydantic_extra__. However, this is not the case. So, any extra fields set by attribute (i.e. as above or setattr(m, "extra_field", "extra_value") are not included in model_dump() or model_dump_json().
Example Code
from pydantic import BaseModel, ConfigDict
class Foo(BaseModel):
model_config = ConfigDict(extra="allow")
foo = Foo()
foo.extra_field = "extra_value"
assert "extra_field" not in foo.model_dump()Python, Pydantic & OS Version
pydantic version: 2.0
pydantic-core version: 2.0.1 release build profile
install path: ~/home/user/venv/lib/python3.9/site-packages/pydantic
python version: 3.9.16 (main, Mar 24 2023, 12:31:28) [Clang 14.0.0 (clang-1400.0.29.202)]
platform: macOS-13.2.1-arm64-arm-64bit
optional deps. installed: ['typing-extensions']
Selected Assignee: @samuelcolvin