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vconnect-api/venv/lib/python3.12/site-packages/pydantic/_internal/_fields.py
2025-12-08 21:35:55 +09:00

636 lines
27 KiB
Python

"""Private logic related to fields (the `Field()` function and `FieldInfo` class), and arguments to `Annotated`."""
from __future__ import annotations as _annotations
import dataclasses
import warnings
from collections.abc import Mapping
from functools import cache
from inspect import Parameter, ismethoddescriptor, signature
from re import Pattern
from typing import TYPE_CHECKING, Any, Callable, TypeVar
from pydantic_core import PydanticUndefined
from typing_extensions import TypeIs
from typing_inspection.introspection import AnnotationSource
from pydantic import PydanticDeprecatedSince211
from pydantic.errors import PydanticUserError
from ..aliases import AliasGenerator
from . import _generics, _typing_extra
from ._config import ConfigWrapper
from ._docs_extraction import extract_docstrings_from_cls
from ._import_utils import import_cached_base_model, import_cached_field_info
from ._namespace_utils import NsResolver
from ._repr import Representation
from ._utils import can_be_positional, get_first_not_none
if TYPE_CHECKING:
from annotated_types import BaseMetadata
from ..fields import FieldInfo
from ..main import BaseModel
from ._dataclasses import PydanticDataclass, StandardDataclass
from ._decorators import DecoratorInfos
class PydanticMetadata(Representation):
"""Base class for annotation markers like `Strict`."""
__slots__ = ()
def pydantic_general_metadata(**metadata: Any) -> BaseMetadata:
"""Create a new `_PydanticGeneralMetadata` class with the given metadata.
Args:
**metadata: The metadata to add.
Returns:
The new `_PydanticGeneralMetadata` class.
"""
return _general_metadata_cls()(metadata) # type: ignore
@cache
def _general_metadata_cls() -> type[BaseMetadata]:
"""Do it this way to avoid importing `annotated_types` at import time."""
from annotated_types import BaseMetadata
class _PydanticGeneralMetadata(PydanticMetadata, BaseMetadata):
"""Pydantic general metadata like `max_digits`."""
def __init__(self, metadata: Any):
self.__dict__ = metadata
return _PydanticGeneralMetadata # type: ignore
def _check_protected_namespaces(
protected_namespaces: tuple[str | Pattern[str], ...],
ann_name: str,
bases: tuple[type[Any], ...],
cls_name: str,
) -> None:
BaseModel = import_cached_base_model()
for protected_namespace in protected_namespaces:
ns_violation = False
if isinstance(protected_namespace, Pattern):
ns_violation = protected_namespace.match(ann_name) is not None
elif isinstance(protected_namespace, str):
ns_violation = ann_name.startswith(protected_namespace)
if ns_violation:
for b in bases:
if hasattr(b, ann_name):
if not (issubclass(b, BaseModel) and ann_name in getattr(b, '__pydantic_fields__', {})):
raise ValueError(
f'Field {ann_name!r} conflicts with member {getattr(b, ann_name)}'
f' of protected namespace {protected_namespace!r}.'
)
else:
valid_namespaces: list[str] = []
for pn in protected_namespaces:
if isinstance(pn, Pattern):
if not pn.match(ann_name):
valid_namespaces.append(f're.compile({pn.pattern!r})')
else:
if not ann_name.startswith(pn):
valid_namespaces.append(f"'{pn}'")
valid_namespaces_str = f'({", ".join(valid_namespaces)}{",)" if len(valid_namespaces) == 1 else ")"}'
warnings.warn(
f'Field {ann_name!r} in {cls_name!r} conflicts with protected namespace {protected_namespace!r}.\n\n'
f"You may be able to solve this by setting the 'protected_namespaces' configuration to {valid_namespaces_str}.",
UserWarning,
stacklevel=5,
)
def _update_fields_from_docstrings(cls: type[Any], fields: dict[str, FieldInfo], use_inspect: bool = False) -> None:
fields_docs = extract_docstrings_from_cls(cls, use_inspect=use_inspect)
for ann_name, field_info in fields.items():
if field_info.description is None and ann_name in fields_docs:
field_info.description = fields_docs[ann_name]
def _apply_field_title_generator_to_field_info(
title_generator: Callable[[str, FieldInfo], str],
field_name: str,
field_info: FieldInfo,
):
if field_info.title is None:
title = title_generator(field_name, field_info)
if not isinstance(title, str):
raise TypeError(f'field_title_generator {title_generator} must return str, not {title.__class__}')
field_info.title = title
def _apply_alias_generator_to_field_info(
alias_generator: Callable[[str], str] | AliasGenerator, field_name: str, field_info: FieldInfo
):
"""Apply an alias generator to aliases on a `FieldInfo` instance if appropriate.
Args:
alias_generator: A callable that takes a string and returns a string, or an `AliasGenerator` instance.
field_name: The name of the field from which to generate the alias.
field_info: The `FieldInfo` instance to which the alias generator is (maybe) applied.
"""
# Apply an alias_generator if
# 1. An alias is not specified
# 2. An alias is specified, but the priority is <= 1
if (
field_info.alias_priority is None
or field_info.alias_priority <= 1
or field_info.alias is None
or field_info.validation_alias is None
or field_info.serialization_alias is None
):
alias, validation_alias, serialization_alias = None, None, None
if isinstance(alias_generator, AliasGenerator):
alias, validation_alias, serialization_alias = alias_generator.generate_aliases(field_name)
elif callable(alias_generator):
alias = alias_generator(field_name)
if not isinstance(alias, str):
raise TypeError(f'alias_generator {alias_generator} must return str, not {alias.__class__}')
# if priority is not set, we set to 1
# which supports the case where the alias_generator from a child class is used
# to generate an alias for a field in a parent class
if field_info.alias_priority is None or field_info.alias_priority <= 1:
field_info.alias_priority = 1
# if the priority is 1, then we set the aliases to the generated alias
if field_info.alias_priority == 1:
field_info.serialization_alias = get_first_not_none(serialization_alias, alias)
field_info.validation_alias = get_first_not_none(validation_alias, alias)
field_info.alias = alias
# if any of the aliases are not set, then we set them to the corresponding generated alias
if field_info.alias is None:
field_info.alias = alias
if field_info.serialization_alias is None:
field_info.serialization_alias = get_first_not_none(serialization_alias, alias)
if field_info.validation_alias is None:
field_info.validation_alias = get_first_not_none(validation_alias, alias)
def update_field_from_config(config_wrapper: ConfigWrapper, field_name: str, field_info: FieldInfo) -> None:
"""Update the `FieldInfo` instance from the configuration set on the model it belongs to.
This will apply the title and alias generators from the configuration.
Args:
config_wrapper: The configuration from the model.
field_name: The field name the `FieldInfo` instance is attached to.
field_info: The `FieldInfo` instance to update.
"""
field_title_generator = field_info.field_title_generator or config_wrapper.field_title_generator
if field_title_generator is not None:
_apply_field_title_generator_to_field_info(field_title_generator, field_name, field_info)
if config_wrapper.alias_generator is not None:
_apply_alias_generator_to_field_info(config_wrapper.alias_generator, field_name, field_info)
_deprecated_method_names = {'dict', 'json', 'copy', '_iter', '_copy_and_set_values', '_calculate_keys'}
_deprecated_classmethod_names = {
'parse_obj',
'parse_raw',
'parse_file',
'from_orm',
'construct',
'schema',
'schema_json',
'validate',
'update_forward_refs',
'_get_value',
}
def collect_model_fields( # noqa: C901
cls: type[BaseModel],
config_wrapper: ConfigWrapper,
ns_resolver: NsResolver | None,
*,
typevars_map: Mapping[TypeVar, Any] | None = None,
) -> tuple[dict[str, FieldInfo], set[str]]:
"""Collect the fields and class variables names of a nascent Pydantic model.
The fields collection process is *lenient*, meaning it won't error if string annotations
fail to evaluate. If this happens, the original annotation (and assigned value, if any)
is stored on the created `FieldInfo` instance.
The `rebuild_model_fields()` should be called at a later point (e.g. when rebuilding the model),
and will make use of these stored attributes.
Args:
cls: BaseModel or dataclass.
config_wrapper: The config wrapper instance.
ns_resolver: Namespace resolver to use when getting model annotations.
typevars_map: A dictionary mapping type variables to their concrete types.
Returns:
A two-tuple containing model fields and class variables names.
Raises:
NameError:
- If there is a conflict between a field name and protected namespaces.
- If there is a field other than `root` in `RootModel`.
- If a field shadows an attribute in the parent model.
"""
FieldInfo_ = import_cached_field_info()
BaseModel_ = import_cached_base_model()
bases = cls.__bases__
parent_fields_lookup: dict[str, FieldInfo] = {}
for base in reversed(bases):
if model_fields := getattr(base, '__pydantic_fields__', None):
parent_fields_lookup.update(model_fields)
type_hints = _typing_extra.get_model_type_hints(cls, ns_resolver=ns_resolver)
# https://docs.python.org/3/howto/annotations.html#accessing-the-annotations-dict-of-an-object-in-python-3-9-and-older
# annotations is only used for finding fields in parent classes
annotations = _typing_extra.safe_get_annotations(cls)
fields: dict[str, FieldInfo] = {}
class_vars: set[str] = set()
for ann_name, (ann_type, evaluated) in type_hints.items():
if ann_name == 'model_config':
# We never want to treat `model_config` as a field
# Note: we may need to change this logic if/when we introduce a `BareModel` class with no
# protected namespaces (where `model_config` might be allowed as a field name)
continue
_check_protected_namespaces(
protected_namespaces=config_wrapper.protected_namespaces,
ann_name=ann_name,
bases=bases,
cls_name=cls.__name__,
)
if _typing_extra.is_classvar_annotation(ann_type):
class_vars.add(ann_name)
continue
assigned_value = getattr(cls, ann_name, PydanticUndefined)
if assigned_value is not PydanticUndefined and (
# One of the deprecated instance methods was used as a field name (e.g. `dict()`):
any(getattr(BaseModel_, depr_name, None) is assigned_value for depr_name in _deprecated_method_names)
# One of the deprecated class methods was used as a field name (e.g. `schema()`):
or (
hasattr(assigned_value, '__func__')
and any(
getattr(getattr(BaseModel_, depr_name, None), '__func__', None) is assigned_value.__func__ # pyright: ignore[reportAttributeAccessIssue]
for depr_name in _deprecated_classmethod_names
)
)
):
# Then `assigned_value` would be the method, even though no default was specified:
assigned_value = PydanticUndefined
if not is_valid_field_name(ann_name):
continue
if cls.__pydantic_root_model__ and ann_name != 'root':
raise NameError(
f"Unexpected field with name {ann_name!r}; only 'root' is allowed as a field of a `RootModel`"
)
# when building a generic model with `MyModel[int]`, the generic_origin check makes sure we don't get
# "... shadows an attribute" warnings
generic_origin = getattr(cls, '__pydantic_generic_metadata__', {}).get('origin')
for base in bases:
dataclass_fields = {
field.name for field in (dataclasses.fields(base) if dataclasses.is_dataclass(base) else ())
}
if hasattr(base, ann_name):
if base is generic_origin:
# Don't warn when "shadowing" of attributes in parametrized generics
continue
if ann_name in dataclass_fields:
# Don't warn when inheriting stdlib dataclasses whose fields are "shadowed" by defaults being set
# on the class instance.
continue
if ann_name not in annotations:
# Don't warn when a field exists in a parent class but has not been defined in the current class
continue
warnings.warn(
f'Field name "{ann_name}" in "{cls.__qualname__}" shadows an attribute in parent '
f'"{base.__qualname__}"',
UserWarning,
stacklevel=4,
)
if assigned_value is PydanticUndefined: # no assignment, just a plain annotation
if ann_name in annotations or ann_name not in parent_fields_lookup:
# field is either:
# - present in the current model's annotations (and *not* from parent classes)
# - not found on any base classes; this seems to be caused by fields bot getting
# generated due to models not being fully defined while initializing recursive models.
# Nothing stops us from just creating a `FieldInfo` for this type hint, so we do this.
field_info = FieldInfo_.from_annotation(ann_type, _source=AnnotationSource.CLASS)
if not evaluated:
field_info._complete = False
# Store the original annotation that should be used to rebuild
# the field info later:
field_info._original_annotation = ann_type
else:
# The field was present on one of the (possibly multiple) base classes
# copy the field to make sure typevar substitutions don't cause issues with the base classes
field_info = parent_fields_lookup[ann_name]._copy()
else: # An assigned value is present (either the default value, or a `Field()` function)
if isinstance(assigned_value, FieldInfo_) and ismethoddescriptor(assigned_value.default):
# `assigned_value` was fetched using `getattr`, which triggers a call to `__get__`
# for descriptors, so we do the same if the `= field(default=...)` form is used.
# Note that we only do this for method descriptors for now, we might want to
# extend this to any descriptor in the future (by simply checking for
# `hasattr(assigned_value.default, '__get__')`).
default = assigned_value.default.__get__(None, cls)
assigned_value.default = default
assigned_value._attributes_set['default'] = default
field_info = FieldInfo_.from_annotated_attribute(ann_type, assigned_value, _source=AnnotationSource.CLASS)
# Store the original annotation and assignment value that should be used to rebuild the field info later.
# Note that the assignment is always stored as the annotation might contain a type var that is later
# parameterized with an unknown forward reference (and we'll need it to rebuild the field info):
field_info._original_assignment = assigned_value
if not evaluated:
field_info._complete = False
field_info._original_annotation = ann_type
elif 'final' in field_info._qualifiers and not field_info.is_required():
warnings.warn(
f'Annotation {ann_name!r} is marked as final and has a default value. Pydantic treats {ann_name!r} as a '
'class variable, but it will be considered as a normal field in V3 to be aligned with dataclasses. If you '
f'still want {ann_name!r} to be considered as a class variable, annotate it as: `ClassVar[<type>] = <default>.`',
category=PydanticDeprecatedSince211,
# Incorrect when `create_model` is used, but the chance that final with a default is used is low in that case:
stacklevel=4,
)
class_vars.add(ann_name)
continue
# attributes which are fields are removed from the class namespace:
# 1. To match the behaviour of annotation-only fields
# 2. To avoid false positives in the NameError check above
try:
delattr(cls, ann_name)
except AttributeError:
pass # indicates the attribute was on a parent class
# Use cls.__dict__['__pydantic_decorators__'] instead of cls.__pydantic_decorators__
# to make sure the decorators have already been built for this exact class
decorators: DecoratorInfos = cls.__dict__['__pydantic_decorators__']
if ann_name in decorators.computed_fields:
raise TypeError(
f'Field {ann_name!r} of class {cls.__name__!r} overrides symbol of same name in a parent class. '
'This override with a computed_field is incompatible.'
)
fields[ann_name] = field_info
if field_info._complete:
# If not complete, this will be called in `rebuild_model_fields()`:
update_field_from_config(config_wrapper, ann_name, field_info)
if typevars_map:
for field in fields.values():
if field._complete:
field.apply_typevars_map(typevars_map)
if config_wrapper.use_attribute_docstrings:
_update_fields_from_docstrings(cls, fields)
return fields, class_vars
def rebuild_model_fields(
cls: type[BaseModel],
*,
config_wrapper: ConfigWrapper,
ns_resolver: NsResolver,
typevars_map: Mapping[TypeVar, Any],
) -> dict[str, FieldInfo]:
"""Rebuild the (already present) model fields by trying to reevaluate annotations.
This function should be called whenever a model with incomplete fields is encountered.
Raises:
NameError: If one of the annotations failed to evaluate.
Note:
This function *doesn't* mutate the model fields in place, as it can be called during
schema generation, where you don't want to mutate other model's fields.
"""
FieldInfo_ = import_cached_field_info()
rebuilt_fields: dict[str, FieldInfo] = {}
with ns_resolver.push(cls):
for f_name, field_info in cls.__pydantic_fields__.items():
if field_info._complete:
rebuilt_fields[f_name] = field_info
else:
existing_desc = field_info.description
ann = _typing_extra.eval_type(
field_info._original_annotation,
*ns_resolver.types_namespace,
)
ann = _generics.replace_types(ann, typevars_map)
if (assign := field_info._original_assignment) is PydanticUndefined:
new_field = FieldInfo_.from_annotation(ann, _source=AnnotationSource.CLASS)
else:
new_field = FieldInfo_.from_annotated_attribute(ann, assign, _source=AnnotationSource.CLASS)
# The description might come from the docstring if `use_attribute_docstrings` was `True`:
new_field.description = new_field.description if new_field.description is not None else existing_desc
update_field_from_config(config_wrapper, f_name, new_field)
rebuilt_fields[f_name] = new_field
return rebuilt_fields
def collect_dataclass_fields(
cls: type[StandardDataclass],
*,
config_wrapper: ConfigWrapper,
ns_resolver: NsResolver | None = None,
typevars_map: dict[Any, Any] | None = None,
) -> dict[str, FieldInfo]:
"""Collect the fields of a dataclass.
Args:
cls: dataclass.
config_wrapper: The config wrapper instance.
ns_resolver: Namespace resolver to use when getting dataclass annotations.
Defaults to an empty instance.
typevars_map: A dictionary mapping type variables to their concrete types.
Returns:
The dataclass fields.
"""
FieldInfo_ = import_cached_field_info()
fields: dict[str, FieldInfo] = {}
ns_resolver = ns_resolver or NsResolver()
dataclass_fields = cls.__dataclass_fields__
# The logic here is similar to `_typing_extra.get_cls_type_hints`,
# although we do it manually as stdlib dataclasses already have annotations
# collected in each class:
for base in reversed(cls.__mro__):
if not dataclasses.is_dataclass(base):
continue
with ns_resolver.push(base):
for ann_name, dataclass_field in dataclass_fields.items():
base_anns = _typing_extra.safe_get_annotations(base)
if ann_name not in base_anns:
# `__dataclass_fields__`contains every field, even the ones from base classes.
# Only collect the ones defined on `base`.
continue
globalns, localns = ns_resolver.types_namespace
ann_type, evaluated = _typing_extra.try_eval_type(dataclass_field.type, globalns, localns)
if _typing_extra.is_classvar_annotation(ann_type):
continue
if (
not dataclass_field.init
and dataclass_field.default is dataclasses.MISSING
and dataclass_field.default_factory is dataclasses.MISSING
):
# TODO: We should probably do something with this so that validate_assignment behaves properly
# Issue: https://github.com/pydantic/pydantic/issues/5470
continue
if isinstance(dataclass_field.default, FieldInfo_):
if dataclass_field.default.init_var:
if dataclass_field.default.init is False:
raise PydanticUserError(
f'Dataclass field {ann_name} has init=False and init_var=True, but these are mutually exclusive.',
code='clashing-init-and-init-var',
)
# TODO: same note as above re validate_assignment
continue
field_info = FieldInfo_.from_annotated_attribute(
ann_type, dataclass_field.default, _source=AnnotationSource.DATACLASS
)
field_info._original_assignment = dataclass_field.default
else:
field_info = FieldInfo_.from_annotated_attribute(
ann_type, dataclass_field, _source=AnnotationSource.DATACLASS
)
field_info._original_assignment = dataclass_field
if not evaluated:
field_info._complete = False
field_info._original_annotation = ann_type
fields[ann_name] = field_info
update_field_from_config(config_wrapper, ann_name, field_info)
if field_info.default is not PydanticUndefined and isinstance(
getattr(cls, ann_name, field_info), FieldInfo_
):
# We need this to fix the default when the "default" from __dataclass_fields__ is a pydantic.FieldInfo
setattr(cls, ann_name, field_info.default)
if typevars_map:
for field in fields.values():
# We don't pass any ns, as `field.annotation`
# was already evaluated. TODO: is this method relevant?
# Can't we juste use `_generics.replace_types`?
field.apply_typevars_map(typevars_map)
if config_wrapper.use_attribute_docstrings:
_update_fields_from_docstrings(
cls,
fields,
# We can't rely on the (more reliable) frame inspection method
# for stdlib dataclasses:
use_inspect=not hasattr(cls, '__is_pydantic_dataclass__'),
)
return fields
def rebuild_dataclass_fields(
cls: type[PydanticDataclass],
*,
config_wrapper: ConfigWrapper,
ns_resolver: NsResolver,
typevars_map: Mapping[TypeVar, Any],
) -> dict[str, FieldInfo]:
"""Rebuild the (already present) dataclass fields by trying to reevaluate annotations.
This function should be called whenever a dataclass with incomplete fields is encountered.
Raises:
NameError: If one of the annotations failed to evaluate.
Note:
This function *doesn't* mutate the dataclass fields in place, as it can be called during
schema generation, where you don't want to mutate other dataclass's fields.
"""
FieldInfo_ = import_cached_field_info()
rebuilt_fields: dict[str, FieldInfo] = {}
with ns_resolver.push(cls):
for f_name, field_info in cls.__pydantic_fields__.items():
if field_info._complete:
rebuilt_fields[f_name] = field_info
else:
existing_desc = field_info.description
ann = _typing_extra.eval_type(
field_info._original_annotation,
*ns_resolver.types_namespace,
)
ann = _generics.replace_types(ann, typevars_map)
new_field = FieldInfo_.from_annotated_attribute(
ann,
field_info._original_assignment,
_source=AnnotationSource.DATACLASS,
)
# The description might come from the docstring if `use_attribute_docstrings` was `True`:
new_field.description = new_field.description if new_field.description is not None else existing_desc
update_field_from_config(config_wrapper, f_name, new_field)
rebuilt_fields[f_name] = new_field
return rebuilt_fields
def is_valid_field_name(name: str) -> bool:
return not name.startswith('_')
def is_valid_privateattr_name(name: str) -> bool:
return name.startswith('_') and not name.startswith('__')
def takes_validated_data_argument(
default_factory: Callable[[], Any] | Callable[[dict[str, Any]], Any],
) -> TypeIs[Callable[[dict[str, Any]], Any]]:
"""Whether the provided default factory callable has a validated data parameter."""
try:
sig = signature(default_factory)
except (ValueError, TypeError):
# `inspect.signature` might not be able to infer a signature, e.g. with C objects.
# In this case, we assume no data argument is present:
return False
parameters = list(sig.parameters.values())
return len(parameters) == 1 and can_be_positional(parameters[0]) and parameters[0].default is Parameter.empty