You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
278 lines
11 KiB
278 lines
11 KiB
"""Provide an enhanced dataclass that performs validation.""" |
|
from __future__ import annotations as _annotations |
|
|
|
import dataclasses |
|
import sys |
|
import types |
|
from typing import TYPE_CHECKING, Any, Callable, Generic, NoReturn, TypeVar, overload |
|
|
|
from typing_extensions import Literal, dataclass_transform |
|
|
|
from ._internal import _config, _decorators, _typing_extra |
|
from ._internal import _dataclasses as _pydantic_dataclasses |
|
from ._migration import getattr_migration |
|
from .config import ConfigDict |
|
from .fields import Field |
|
|
|
if TYPE_CHECKING: |
|
from ._internal._dataclasses import PydanticDataclass |
|
|
|
__all__ = 'dataclass', 'rebuild_dataclass' |
|
|
|
_T = TypeVar('_T') |
|
|
|
if sys.version_info >= (3, 10): |
|
|
|
@dataclass_transform(field_specifiers=(dataclasses.field, Field)) |
|
@overload |
|
def dataclass( |
|
*, |
|
init: Literal[False] = False, |
|
repr: bool = True, |
|
eq: bool = True, |
|
order: bool = False, |
|
unsafe_hash: bool = False, |
|
frozen: bool = False, |
|
config: ConfigDict | type[object] | None = None, |
|
validate_on_init: bool | None = None, |
|
kw_only: bool = ..., |
|
slots: bool = ..., |
|
) -> Callable[[type[_T]], type[PydanticDataclass]]: # type: ignore |
|
... |
|
|
|
@dataclass_transform(field_specifiers=(dataclasses.field, Field)) |
|
@overload |
|
def dataclass( |
|
_cls: type[_T], # type: ignore |
|
*, |
|
init: Literal[False] = False, |
|
repr: bool = True, |
|
eq: bool = True, |
|
order: bool = False, |
|
unsafe_hash: bool = False, |
|
frozen: bool = False, |
|
config: ConfigDict | type[object] | None = None, |
|
validate_on_init: bool | None = None, |
|
kw_only: bool = ..., |
|
slots: bool = ..., |
|
) -> type[PydanticDataclass]: |
|
... |
|
|
|
else: |
|
|
|
@dataclass_transform(field_specifiers=(dataclasses.field, Field)) |
|
@overload |
|
def dataclass( |
|
*, |
|
init: Literal[False] = False, |
|
repr: bool = True, |
|
eq: bool = True, |
|
order: bool = False, |
|
unsafe_hash: bool = False, |
|
frozen: bool = False, |
|
config: ConfigDict | type[object] | None = None, |
|
validate_on_init: bool | None = None, |
|
) -> Callable[[type[_T]], type[PydanticDataclass]]: # type: ignore |
|
... |
|
|
|
@dataclass_transform(field_specifiers=(dataclasses.field, Field)) |
|
@overload |
|
def dataclass( |
|
_cls: type[_T], # type: ignore |
|
*, |
|
init: Literal[False] = False, |
|
repr: bool = True, |
|
eq: bool = True, |
|
order: bool = False, |
|
unsafe_hash: bool = False, |
|
frozen: bool = False, |
|
config: ConfigDict | type[object] | None = None, |
|
validate_on_init: bool | None = None, |
|
) -> type[PydanticDataclass]: |
|
... |
|
|
|
|
|
@dataclass_transform(field_specifiers=(dataclasses.field, Field)) |
|
def dataclass( |
|
_cls: type[_T] | None = None, |
|
*, |
|
init: Literal[False] = False, |
|
repr: bool = True, |
|
eq: bool = True, |
|
order: bool = False, |
|
unsafe_hash: bool = False, |
|
frozen: bool = False, |
|
config: ConfigDict | type[object] | None = None, |
|
validate_on_init: bool | None = None, |
|
kw_only: bool = False, |
|
slots: bool = False, |
|
) -> Callable[[type[_T]], type[PydanticDataclass]] | type[PydanticDataclass]: |
|
"""Usage docs: https://docs.pydantic.dev/2.2/usage/dataclasses/ |
|
|
|
A decorator used to create a Pydantic-enhanced dataclass, similar to the standard Python `dataclass`, |
|
but with added validation. |
|
|
|
This function should be used similarly to `dataclasses.dataclass`. |
|
|
|
Args: |
|
_cls: The target `dataclass`. |
|
init: Included for signature compatibility with `dataclasses.dataclass`, and is passed through to |
|
`dataclasses.dataclass` when appropriate. If specified, must be set to `False`, as pydantic inserts its |
|
own `__init__` function. |
|
repr: A boolean indicating whether or not to include the field in the `__repr__` output. |
|
eq: Determines if a `__eq__` should be generated for the class. |
|
order: Determines if comparison magic methods should be generated, such as `__lt__`, but not `__eq__`. |
|
unsafe_hash: Determines if an unsafe hashing function should be included in the class. |
|
frozen: Determines if the generated class should be a 'frozen' `dataclass`, which does not allow its |
|
attributes to be modified from its constructor. |
|
config: A configuration for the `dataclass` generation. |
|
validate_on_init: A deprecated parameter included for backwards compatibility; in V2, all Pydantic dataclasses |
|
are validated on init. |
|
kw_only: Determines if `__init__` method parameters must be specified by keyword only. Defaults to `False`. |
|
slots: Determines if the generated class should be a 'slots' `dataclass`, which does not allow the addition of |
|
new attributes after instantiation. |
|
|
|
Returns: |
|
A decorator that accepts a class as its argument and returns a Pydantic `dataclass`. |
|
|
|
Raises: |
|
AssertionError: Raised if `init` is not `False` or `validate_on_init` is `False`. |
|
""" |
|
assert init is False, 'pydantic.dataclasses.dataclass only supports init=False' |
|
assert validate_on_init is not False, 'validate_on_init=False is no longer supported' |
|
|
|
if sys.version_info >= (3, 10): |
|
kwargs = dict(kw_only=kw_only, slots=slots) |
|
else: |
|
kwargs = {} |
|
|
|
def create_dataclass(cls: type[Any]) -> type[PydanticDataclass]: |
|
"""Create a Pydantic dataclass from a regular dataclass. |
|
|
|
Args: |
|
cls: The class to create the Pydantic dataclass from. |
|
|
|
Returns: |
|
A Pydantic dataclass. |
|
""" |
|
original_cls = cls |
|
|
|
config_dict = config |
|
if config_dict is None: |
|
# if not explicitly provided, read from the type |
|
cls_config = getattr(cls, '__pydantic_config__', None) |
|
if cls_config is not None: |
|
config_dict = cls_config |
|
config_wrapper = _config.ConfigWrapper(config_dict) |
|
decorators = _decorators.DecoratorInfos.build(cls) |
|
|
|
# Keep track of the original __doc__ so that we can restore it after applying the dataclasses decorator |
|
# Otherwise, classes with no __doc__ will have their signature added into the JSON schema description, |
|
# since dataclasses.dataclass will set this as the __doc__ |
|
original_doc = cls.__doc__ |
|
|
|
if _pydantic_dataclasses.is_builtin_dataclass(cls): |
|
# Don't preserve the docstring for vanilla dataclasses, as it may include the signature |
|
# This matches v1 behavior, and there was an explicit test for it |
|
original_doc = None |
|
|
|
# We don't want to add validation to the existing std lib dataclass, so we will subclass it |
|
# If the class is generic, we need to make sure the subclass also inherits from Generic |
|
# with all the same parameters. |
|
bases = (cls,) |
|
if issubclass(cls, Generic): |
|
generic_base = Generic[cls.__parameters__] # type: ignore |
|
bases = bases + (generic_base,) |
|
cls = types.new_class(cls.__name__, bases) |
|
|
|
cls = dataclasses.dataclass( # type: ignore[call-overload] |
|
cls, |
|
# the value of init here doesn't affect anything except that it makes it easier to generate a signature |
|
init=True, |
|
repr=repr, |
|
eq=eq, |
|
order=order, |
|
unsafe_hash=unsafe_hash, |
|
frozen=frozen, |
|
**kwargs, |
|
) |
|
|
|
cls.__pydantic_decorators__ = decorators # type: ignore |
|
cls.__doc__ = original_doc |
|
cls.__module__ = original_cls.__module__ |
|
cls.__qualname__ = original_cls.__qualname__ |
|
pydantic_complete = _pydantic_dataclasses.complete_dataclass( |
|
cls, config_wrapper, raise_errors=False, types_namespace=None |
|
) |
|
cls.__pydantic_complete__ = pydantic_complete # type: ignore |
|
return cls |
|
|
|
if _cls is None: |
|
return create_dataclass |
|
|
|
return create_dataclass(_cls) |
|
|
|
|
|
__getattr__ = getattr_migration(__name__) |
|
|
|
if (3, 8) <= sys.version_info < (3, 11): |
|
# Monkeypatch dataclasses.InitVar so that typing doesn't error if it occurs as a type when evaluating type hints |
|
# Starting in 3.11, typing.get_type_hints will not raise an error if the retrieved type hints are not callable. |
|
|
|
def _call_initvar(*args: Any, **kwargs: Any) -> NoReturn: |
|
"""This function does nothing but raise an error that is as similar as possible to what you'd get |
|
if you were to try calling `InitVar[int]()` without this monkeypatch. The whole purpose is just |
|
to ensure typing._type_check does not error if the type hint evaluates to `InitVar[<parameter>]`. |
|
""" |
|
raise TypeError("'InitVar' object is not callable") |
|
|
|
dataclasses.InitVar.__call__ = _call_initvar |
|
|
|
|
|
def rebuild_dataclass( |
|
cls: type[PydanticDataclass], |
|
*, |
|
force: bool = False, |
|
raise_errors: bool = True, |
|
_parent_namespace_depth: int = 2, |
|
_types_namespace: dict[str, Any] | None = None, |
|
) -> bool | None: |
|
"""Try to rebuild the pydantic-core schema for the dataclass. |
|
|
|
This may be necessary when one of the annotations is a ForwardRef which could not be resolved during |
|
the initial attempt to build the schema, and automatic rebuilding fails. |
|
|
|
This is analogous to `BaseModel.model_rebuild`. |
|
|
|
Args: |
|
cls: The class to build the dataclass core schema for. |
|
force: Whether to force the rebuilding of the model schema, defaults to `False`. |
|
raise_errors: Whether to raise errors, defaults to `True`. |
|
_parent_namespace_depth: The depth level of the parent namespace, defaults to 2. |
|
_types_namespace: The types namespace, defaults to `None`. |
|
|
|
Returns: |
|
Returns `None` if the schema is already "complete" and rebuilding was not required. |
|
If rebuilding _was_ required, returns `True` if rebuilding was successful, otherwise `False`. |
|
""" |
|
if not force and cls.__pydantic_complete__: |
|
return None |
|
else: |
|
if _types_namespace is not None: |
|
types_namespace: dict[str, Any] | None = _types_namespace.copy() |
|
else: |
|
if _parent_namespace_depth > 0: |
|
frame_parent_ns = _typing_extra.parent_frame_namespace(parent_depth=_parent_namespace_depth) or {} |
|
# Note: we may need to add something similar to cls.__pydantic_parent_namespace__ from BaseModel |
|
# here when implementing handling of recursive generics. See BaseModel.model_rebuild for reference. |
|
types_namespace = frame_parent_ns |
|
else: |
|
types_namespace = {} |
|
|
|
types_namespace = _typing_extra.get_cls_types_namespace(cls, types_namespace) |
|
return _pydantic_dataclasses.complete_dataclass( |
|
cls, |
|
_config.ConfigWrapper(cls.__pydantic_config__, check=False), |
|
raise_errors=raise_errors, |
|
types_namespace=types_namespace, |
|
)
|
|
|