Key order not conserved in OrderedDicts #12273
Description
Initial Checks
- I confirm that I'm using Pydantic V2
Description
It looks like OrderedDict fields are broken, as can be seen in the example below:
from collections import OrderedDict
import pydantic
class Model(pydantic.BaseModel):
foo: OrderedDict
foo = OrderedDict({"a": 1, "b": 2})
foo.move_to_end("a")
model1 = Model(foo=foo) # this doesn't work
model2 = Model(foo=dict(foo)) # this works
print(foo.keys(), model1.foo.keys(), model2.foo.keys())Output:
odict_keys(['b', 'a']) odict_keys(['a', 'b']) odict_keys(['b', 'a'])
Example Code
Python, Pydantic & OS Version
pydantic version: 2.11.6
pydantic-core version: 2.33.2
pydantic-core build: profile=release pgo=false
python version: 3.12.11 | packaged by conda-forge | (main, Jun 4 2025, 14:45:31) [GCC 13.3.0]
platform: Linux-5.15.0-1061-nvidia-x86_64-with-glibc2.35
related packages: typing_extensions-4.14.0 fastapi-0.115.12 mypy-1.16.0
commit: unknown