"""Private logic for creating pydantic dataclasses."""
from __future__ import annotations as _annotations
import dataclasses
import typing
import warnings
from functools import partial, wraps
from typing import Any, ClassVar
from pydantic_core import (
ArgsKwargs,
SchemaSerializer,
SchemaValidator,
core_schema,
)
from typing_extensions import TypeGuard
from ..errors import PydanticUndefinedAnnotation
from ..plugin._schema_validator import PluggableSchemaValidator, create_schema_validator
from ..warnings import PydanticDeprecatedSince20
from . import _config, _decorators
from ._fields import collect_dataclass_fields
from ._generate_schema import GenerateSchema
from ._generics import get_standard_typevars_map
from ._mock_val_ser import set_dataclass_mocks
from ._namespace_utils import NsResolver
from ._schema_generation_shared import CallbackGetCoreSchemaHandler
from ._signature import generate_pydantic_signature
from ._utils import LazyClassAttribute
if typing.TYPE_CHECKING:
from _typeshed import DataclassInstance as StandardDataclass
from ..config import ConfigDict
from ..fields import FieldInfo
class PydanticDataclass(StandardDataclass, typing.Protocol):
"""A protocol containing attributes only available once a class has been decorated as a Pydantic dataclass.
Attributes:
__pydantic_config__: Pydantic-specific configuration settings for the dataclass.
__pydantic_complete__: Whether dataclass building is completed, or if there are still undefined fields.
__pydantic_core_schema__: The pydantic-core schema used to build the SchemaValidator and SchemaSerializer.
__pydantic_decorators__: Metadata containing the decorators defined on the dataclass.
__pydantic_fields__: Metadata about the fields defined on the dataclass.
__pydantic_serializer__: The pydantic-core SchemaSerializer used to dump instances of the dataclass.
__pydantic_validator__: The pydantic-core SchemaValidator used to validate instances of the dataclass.
"""
__pydantic_config__: ClassVar[ConfigDict]
__pydantic_complete__: ClassVar[bool]
__pydantic_core_schema__: ClassVar[core_schema.CoreSchema]
__pydantic_decorators__: ClassVar[_decorators.DecoratorInfos]
__pydantic_fields__: ClassVar[dict[str, FieldInfo]]
__pydantic_serializer__: ClassVar[SchemaSerializer]
__pydantic_validator__: ClassVar[SchemaValidator | PluggableSchemaValidator]
else:
# See PyCharm issues https://youtrack.jetbrains.com/issue/PY-21915
# and https://youtrack.jetbrains.com/issue/PY-51428
DeprecationWarning = PydanticDeprecatedSince20
def set_dataclass_fields(
cls: type[StandardDataclass],
ns_resolver: NsResolver | None = None,
config_wrapper: _config.ConfigWrapper | None = None,
) -> None:
"""Collect and set `cls.__pydantic_fields__`.
Args:
cls: The class.
ns_resolver: Namespace resolver to use when getting dataclass annotations.
config_wrapper: The config wrapper instance, defaults to `None`.
"""
typevars_map = get_standard_typevars_map(cls)
fields = collect_dataclass_fields(
cls, ns_resolver=ns_resolver, typevars_map=typevars_map, config_wrapper=config_wrapper
)
cls.__pydantic_fields__ = fields # type: ignore
def complete_dataclass(
cls: type[Any],
config_wrapper: _config.ConfigWrapper,
*,
raise_errors: bool = True,
ns_resolver: NsResolver | None = None,
_force_build: bool = False,
) -> bool:
"""Finish building a pydantic dataclass.
This logic is called on a class which has already been wrapped in `dataclasses.dataclass()`.
This is somewhat analogous to `pydantic._internal._model_construction.complete_model_class`.
Args:
cls: The class.
config_wrapper: The config wrapper instance.
raise_errors: Whether to raise errors, defaults to `True`.
ns_resolver: The namespace resolver instance to use when collecting dataclass fields
and during schema building.
_force_build: Whether to force building the dataclass, no matter if
[`defer_build`][pydantic.config.ConfigDict.defer_build] is set.
Returns:
`True` if building a pydantic dataclass is successfully completed, `False` otherwise.
Raises:
PydanticUndefinedAnnotation: If `raise_error` is `True` and there is an undefined annotations.
"""
original_init = cls.__init__
# dataclass.__init__ must be defined here so its `__qualname__` can be changed since functions can't be copied,
# and so that the mock validator is used if building was deferred:
def __init__(__dataclass_self__: PydanticDataclass, *args: Any, **kwargs: Any) -> None:
__tracebackhide__ = True
s = __dataclass_self__
s.__pydantic_validator__.validate_python(ArgsKwargs(args, kwargs), self_instance=s)
__init__.__qualname__ = f'{cls.__qualname__}.__init__'
cls.__init__ = __init__ # type: ignore
cls.__pydantic_config__ = config_wrapper.config_dict # type: ignore
if not _force_build and config_wrapper.defer_build:
set_dataclass_mocks(cls, cls.__name__)
return False
if hasattr(cls, '__post_init_post_parse__'):
warnings.warn(
'Support for `__post_init_post_parse__` has been dropped, the method will not be called', DeprecationWarning
)
set_dataclass_fields(cls, ns_resolver, config_wrapper=config_wrapper)
typevars_map = get_standard_typevars_map(cls)
gen_schema = GenerateSchema(
config_wrapper,
ns_resolver=ns_resolver,
typevars_map=typevars_map,
)
# set __signature__ attr only for model class, but not for its instances
# (because instances can define `__call__`, and `inspect.signature` shouldn't
# use the `__signature__` attribute and instead generate from `__call__`).
cls.__signature__ = LazyClassAttribute(
'__signature__',
partial(
generate_pydantic_signature,
# It's' important that we reference the original_init here
init=original_init,
fields=cls.__pydantic_fields__, # type: ignore
populate_by_name=config_wrapper.populate_by_name,
extra=config_wrapper.extra,
is_dataclass=True,
),
)
get_core_schema = getattr(cls, '__get_pydantic_core_schema__', None)
try:
if get_core_schema:
schema = get_core_schema(
cls,
CallbackGetCoreSchemaHandler(
partial(gen_schema.generate_schema, from_dunder_get_core_schema=False),
gen_schema,
ref_mode='unpack',
),
)
else:
schema = gen_schema.generate_schema(cls, from_dunder_get_core_schema=False)
except PydanticUndefinedAnnotation as e:
if raise_errors:
raise
set_dataclass_mocks(cls, cls.__name__, f'`{e.name}`')
return False
core_config = config_wrapper.core_config(title=cls.__name__)
try:
schema = gen_schema.clean_schema(schema)
except gen_schema.CollectedInvalid:
set_dataclass_mocks(cls, cls.__name__, 'all referenced types')
return False
# We are about to set all the remaining required properties expected for this cast;
# __pydantic_decorators__ and __pydantic_fields__ should already be set
cls = typing.cast('type[PydanticDataclass]', cls)
# debug(schema)
cls.__pydantic_core_schema__ = schema
cls.__pydantic_validator__ = validator = create_schema_validator(
schema, cls, cls.__module__, cls.__qualname__, 'dataclass', core_config, config_wrapper.plugin_settings
)
cls.__pydantic_serializer__ = SchemaSerializer(schema, core_config)
if config_wrapper.validate_assignment:
@wraps(cls.__setattr__)
def validated_setattr(instance: Any, field: str, value: str, /) -> None:
validator.validate_assignment(instance, field, value)
cls.__setattr__ = validated_setattr.__get__(None, cls) # type: ignore
cls.__pydantic_complete__ = True
return True
def is_builtin_dataclass(_cls: type[Any]) -> TypeGuard[type[StandardDataclass]]:
"""Returns True if a class is a stdlib dataclass and *not* a pydantic dataclass.
We check that
- `_cls` is a dataclass
- `_cls` does not inherit from a processed pydantic dataclass (and thus have a `__pydantic_validator__`)
- `_cls` does not have any annotations that are not dataclass fields
e.g.
```python
import dataclasses
import pydantic.dataclasses
@dataclasses.dataclass
class A:
x: int
@pydantic.dataclasses.dataclass
class B(A):
y: int
```
In this case, when we first check `B`, we make an extra check and look at the annotations ('y'),
which won't be a superset of all the dataclass fields (only the stdlib fields i.e. 'x')
Args:
cls: The class.
Returns:
`True` if the class is a stdlib dataclass, `False` otherwise.
"""
return (
dataclasses.is_dataclass(_cls)
and not hasattr(_cls, '__pydantic_validator__')
and set(_cls.__dataclass_fields__).issuperset(set(getattr(_cls, '__annotations__', {})))
)
