Lazy import

pydantic/config.py

@@ -5,7 +5,6 @@
 
 from typing_extensions import Literal, TypeAlias, TypedDict
 
-from ._internal._utils import is_model_class
 from ._migration import getattr_migration
 from .aliases import AliasGenerator
 from .errors import PydanticUserError
@@ -1023,6 +1022,8 @@ def inner(class_: _TypeT, /) -> _TypeT:
  # Ideally, we would check for `class_` to either be a `TypedDict` or a stdlib dataclass.
  # However, the `@with_config` decorator can be applied *after* `@dataclass`. To avoid
  # common mistakes, we at least check for `class_` to not be a Pydantic model.
+ from ._internal._utils import is_model_class
+
  if is_model_class(class_):
  raise PydanticUserError(
  f'Cannot use `with_config` on {class_.__name__} as it is a Pydantic model',