Description
Initial Checks
- I confirm that I'm using Pydantic V2
Description
The below code will crash with the following error.
Traceback (most recent call last):
File "...", line 9, in <module>
model = Model(a="abc")
^^^^^^^^^^^^^^
File "/.../.venv/lib/python3.12/site-packages/pydantic/main.py", line 214, in __init__
validated_self = self.__pydantic_validator__.validate_python(data, self_instance=self)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File ".../test.py", line 6, in <lambda>
b: int = Field(default_factory=lambda data: 2 * data["a"])
~~~~^^^^^
KeyError: 'a'
I think the problem is that the error from the failed validation of a: int = "abc" isn't immediately raised, and then the call to the default_factory is done with a dictionary that doesn't have the expected keys.
The resulting error is then not really helpful to a user as the KeyError is just a symptom when the actual cause would be the ValidationError that now isn't reported.
Example Code
from pydantic import BaseModel, Field
class Model(BaseModel):
a: int = 1
b: int = Field(default_factory=lambda data: 2 * data["a"])
model = Model(a="abc")Python, Pydantic & OS Version
pydantic version: 2.10.3
pydantic-core version: 2.27.1
pydantic-core build: profile=release pgo=false
install path: /Users/chasse/.../.venv/lib/python3.12/site-packages/pydantic
python version: 3.12.6 (main, Sep 9 2024, 21:36:32) [Clang 18.1.8 ]
platform: macOS-15.3-arm64-arm-64bit
related packages: typing_extensions-4.12.2
commit: unknown