I have the following model in pydantic (Version 2.0.3)
from typing import Tuple
from pydantic import BaseModel
class Model(BaseModel):
test_field: Tuple[int]
But when I enter
model = Model(test_field=(1,2))
I get as error:
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/code.py", line 90, in runcode
exec(code, self.locals)
File "<input>", line 1, in <module>
File "/Users/tobi/Documents/scraiber/z_legacy/fastapi_test_app/venv/lib/python3.10/site-packages/pydantic/main.py", line 150, in __init__
__pydantic_self__.__pydantic_validator__.validate_python(data, self_instance=__pydantic_self__)
pydantic_core._pydantic_core.ValidationError: 1 validation error for Model
test_field
Tuple should have at most 1 item after validation, not 2 [type=too_long, input_value=(1, 2), input_type=tuple]
For further information visit https://errors.pydantic.dev/2.0.3/v/too_long
Do you know how I can fix that?
Following @Tim Robert's Answer, the linked PR suggests using the Ellipsis ... is the syntax you're after!
https://github.com/pydantic/pydantic/pull/512/files
class Model(BaseModel):
test_field: Tuple[int, ...]
>>> Model(test_field=(1,2))
Model(test_field=(1, 2))
Additionally, and though I don't think it's really advisable (prefer codegen or reconsider the design), you can generate and expand given an exact count of the fields
count = 5
class Model_Five(BaseModel):
test_field: Tuple[*([int]*count)]
>>> Model_Five(test_field=(1,2,3,4,5))
Model_Five(test_field=(1, 2, 3, 4, 5))
>>> Model_Five(test_field=(1,2,3,4))
[..] omitted
test_field.4
Field required [type=missing, input_value=(1, 2, 3, 4), input_type=tuple]
For further information visit https://docs.pydantic.dev/dev/errors/validation_errors/#missing
Finally, there might be cases where you need a longer form like *(cls for _ in range(count)) (or the even more troublesome for sustainability *(some_class_factory() for _ in range(count))) to expressly avoid having the inner values refer to the same object