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Diffstat (limited to '.venv/lib/python3.12/site-packages/pydantic/functional_serializers.py')
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diff --git a/.venv/lib/python3.12/site-packages/pydantic/functional_serializers.py b/.venv/lib/python3.12/site-packages/pydantic/functional_serializers.py new file mode 100644 index 00000000..9f850295 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/pydantic/functional_serializers.py @@ -0,0 +1,449 @@ +"""This module contains related classes and functions for serialization.""" + +from __future__ import annotations + +import dataclasses +from functools import partial, partialmethod +from typing import TYPE_CHECKING, Any, Callable, TypeVar, overload + +from pydantic_core import PydanticUndefined, core_schema +from pydantic_core.core_schema import SerializationInfo, SerializerFunctionWrapHandler, WhenUsed +from typing_extensions import Annotated, Literal, TypeAlias + +from . import PydanticUndefinedAnnotation +from ._internal import _decorators, _internal_dataclass +from .annotated_handlers import GetCoreSchemaHandler + + +@dataclasses.dataclass(**_internal_dataclass.slots_true, frozen=True) +class PlainSerializer: + """Plain serializers use a function to modify the output of serialization. + + This is particularly helpful when you want to customize the serialization for annotated types. + Consider an input of `list`, which will be serialized into a space-delimited string. + + ```python + from typing import List + + from typing_extensions import Annotated + + from pydantic import BaseModel, PlainSerializer + + CustomStr = Annotated[ + List, PlainSerializer(lambda x: ' '.join(x), return_type=str) + ] + + class StudentModel(BaseModel): + courses: CustomStr + + student = StudentModel(courses=['Math', 'Chemistry', 'English']) + print(student.model_dump()) + #> {'courses': 'Math Chemistry English'} + ``` + + Attributes: + func: The serializer function. + return_type: The return type for the function. If omitted it will be inferred from the type annotation. + when_used: Determines when this serializer should be used. Accepts a string with values `'always'`, + `'unless-none'`, `'json'`, and `'json-unless-none'`. Defaults to 'always'. + """ + + func: core_schema.SerializerFunction + return_type: Any = PydanticUndefined + when_used: WhenUsed = 'always' + + def __get_pydantic_core_schema__(self, source_type: Any, handler: GetCoreSchemaHandler) -> core_schema.CoreSchema: + """Gets the Pydantic core schema. + + Args: + source_type: The source type. + handler: The `GetCoreSchemaHandler` instance. + + Returns: + The Pydantic core schema. + """ + schema = handler(source_type) + try: + # Do not pass in globals as the function could be defined in a different module. + # Instead, let `get_function_return_type` infer the globals to use, but still pass + # in locals that may contain a parent/rebuild namespace: + return_type = _decorators.get_function_return_type( + self.func, + self.return_type, + localns=handler._get_types_namespace().locals, + ) + except NameError as e: + raise PydanticUndefinedAnnotation.from_name_error(e) from e + return_schema = None if return_type is PydanticUndefined else handler.generate_schema(return_type) + schema['serialization'] = core_schema.plain_serializer_function_ser_schema( + function=self.func, + info_arg=_decorators.inspect_annotated_serializer(self.func, 'plain'), + return_schema=return_schema, + when_used=self.when_used, + ) + return schema + + +@dataclasses.dataclass(**_internal_dataclass.slots_true, frozen=True) +class WrapSerializer: + """Wrap serializers receive the raw inputs along with a handler function that applies the standard serialization + logic, and can modify the resulting value before returning it as the final output of serialization. + + For example, here's a scenario in which a wrap serializer transforms timezones to UTC **and** utilizes the existing `datetime` serialization logic. + + ```python + from datetime import datetime, timezone + from typing import Any, Dict + + from typing_extensions import Annotated + + from pydantic import BaseModel, WrapSerializer + + class EventDatetime(BaseModel): + start: datetime + end: datetime + + def convert_to_utc(value: Any, handler, info) -> Dict[str, datetime]: + # Note that `handler` can actually help serialize the `value` for + # further custom serialization in case it's a subclass. + partial_result = handler(value, info) + if info.mode == 'json': + return { + k: datetime.fromisoformat(v).astimezone(timezone.utc) + for k, v in partial_result.items() + } + return {k: v.astimezone(timezone.utc) for k, v in partial_result.items()} + + UTCEventDatetime = Annotated[EventDatetime, WrapSerializer(convert_to_utc)] + + class EventModel(BaseModel): + event_datetime: UTCEventDatetime + + dt = EventDatetime( + start='2024-01-01T07:00:00-08:00', end='2024-01-03T20:00:00+06:00' + ) + event = EventModel(event_datetime=dt) + print(event.model_dump()) + ''' + { + 'event_datetime': { + 'start': datetime.datetime( + 2024, 1, 1, 15, 0, tzinfo=datetime.timezone.utc + ), + 'end': datetime.datetime( + 2024, 1, 3, 14, 0, tzinfo=datetime.timezone.utc + ), + } + } + ''' + + print(event.model_dump_json()) + ''' + {"event_datetime":{"start":"2024-01-01T15:00:00Z","end":"2024-01-03T14:00:00Z"}} + ''' + ``` + + Attributes: + func: The serializer function to be wrapped. + return_type: The return type for the function. If omitted it will be inferred from the type annotation. + when_used: Determines when this serializer should be used. Accepts a string with values `'always'`, + `'unless-none'`, `'json'`, and `'json-unless-none'`. Defaults to 'always'. + """ + + func: core_schema.WrapSerializerFunction + return_type: Any = PydanticUndefined + when_used: WhenUsed = 'always' + + def __get_pydantic_core_schema__(self, source_type: Any, handler: GetCoreSchemaHandler) -> core_schema.CoreSchema: + """This method is used to get the Pydantic core schema of the class. + + Args: + source_type: Source type. + handler: Core schema handler. + + Returns: + The generated core schema of the class. + """ + schema = handler(source_type) + globalns, localns = handler._get_types_namespace() + try: + # Do not pass in globals as the function could be defined in a different module. + # Instead, let `get_function_return_type` infer the globals to use, but still pass + # in locals that may contain a parent/rebuild namespace: + return_type = _decorators.get_function_return_type( + self.func, + self.return_type, + localns=handler._get_types_namespace().locals, + ) + except NameError as e: + raise PydanticUndefinedAnnotation.from_name_error(e) from e + return_schema = None if return_type is PydanticUndefined else handler.generate_schema(return_type) + schema['serialization'] = core_schema.wrap_serializer_function_ser_schema( + function=self.func, + info_arg=_decorators.inspect_annotated_serializer(self.func, 'wrap'), + return_schema=return_schema, + when_used=self.when_used, + ) + return schema + + +if TYPE_CHECKING: + _Partial: TypeAlias = 'partial[Any] | partialmethod[Any]' + + FieldPlainSerializer: TypeAlias = 'core_schema.SerializerFunction | _Partial' + """A field serializer method or function in `plain` mode.""" + + FieldWrapSerializer: TypeAlias = 'core_schema.WrapSerializerFunction | _Partial' + """A field serializer method or function in `wrap` mode.""" + + FieldSerializer: TypeAlias = 'FieldPlainSerializer | FieldWrapSerializer' + """A field serializer method or function.""" + + _FieldPlainSerializerT = TypeVar('_FieldPlainSerializerT', bound=FieldPlainSerializer) + _FieldWrapSerializerT = TypeVar('_FieldWrapSerializerT', bound=FieldWrapSerializer) + + +@overload +def field_serializer( + field: str, + /, + *fields: str, + mode: Literal['wrap'], + return_type: Any = ..., + when_used: WhenUsed = ..., + check_fields: bool | None = ..., +) -> Callable[[_FieldWrapSerializerT], _FieldWrapSerializerT]: ... + + +@overload +def field_serializer( + field: str, + /, + *fields: str, + mode: Literal['plain'] = ..., + return_type: Any = ..., + when_used: WhenUsed = ..., + check_fields: bool | None = ..., +) -> Callable[[_FieldPlainSerializerT], _FieldPlainSerializerT]: ... + + +def field_serializer( + *fields: str, + mode: Literal['plain', 'wrap'] = 'plain', + return_type: Any = PydanticUndefined, + when_used: WhenUsed = 'always', + check_fields: bool | None = None, +) -> ( + Callable[[_FieldWrapSerializerT], _FieldWrapSerializerT] + | Callable[[_FieldPlainSerializerT], _FieldPlainSerializerT] +): + """Decorator that enables custom field serialization. + + In the below example, a field of type `set` is used to mitigate duplication. A `field_serializer` is used to serialize the data as a sorted list. + + ```python + from typing import Set + + from pydantic import BaseModel, field_serializer + + class StudentModel(BaseModel): + name: str = 'Jane' + courses: Set[str] + + @field_serializer('courses', when_used='json') + def serialize_courses_in_order(self, courses: Set[str]): + return sorted(courses) + + student = StudentModel(courses={'Math', 'Chemistry', 'English'}) + print(student.model_dump_json()) + #> {"name":"Jane","courses":["Chemistry","English","Math"]} + ``` + + See [Custom serializers](../concepts/serialization.md#custom-serializers) for more information. + + Four signatures are supported: + + - `(self, value: Any, info: FieldSerializationInfo)` + - `(self, value: Any, nxt: SerializerFunctionWrapHandler, info: FieldSerializationInfo)` + - `(value: Any, info: SerializationInfo)` + - `(value: Any, nxt: SerializerFunctionWrapHandler, info: SerializationInfo)` + + Args: + fields: Which field(s) the method should be called on. + mode: The serialization mode. + + - `plain` means the function will be called instead of the default serialization logic, + - `wrap` means the function will be called with an argument to optionally call the + default serialization logic. + return_type: Optional return type for the function, if omitted it will be inferred from the type annotation. + when_used: Determines the serializer will be used for serialization. + check_fields: Whether to check that the fields actually exist on the model. + + Returns: + The decorator function. + """ + + def dec(f: FieldSerializer) -> _decorators.PydanticDescriptorProxy[Any]: + dec_info = _decorators.FieldSerializerDecoratorInfo( + fields=fields, + mode=mode, + return_type=return_type, + when_used=when_used, + check_fields=check_fields, + ) + return _decorators.PydanticDescriptorProxy(f, dec_info) # pyright: ignore[reportArgumentType] + + return dec # pyright: ignore[reportReturnType] + + +if TYPE_CHECKING: + # The first argument in the following callables represent the `self` type: + + ModelPlainSerializerWithInfo: TypeAlias = Callable[[Any, SerializationInfo], Any] + """A model serializer method with the `info` argument, in `plain` mode.""" + + ModelPlainSerializerWithoutInfo: TypeAlias = Callable[[Any], Any] + """A model serializer method without the `info` argument, in `plain` mode.""" + + ModelPlainSerializer: TypeAlias = 'ModelPlainSerializerWithInfo | ModelPlainSerializerWithoutInfo' + """A model serializer method in `plain` mode.""" + + ModelWrapSerializerWithInfo: TypeAlias = Callable[[Any, SerializerFunctionWrapHandler, SerializationInfo], Any] + """A model serializer method with the `info` argument, in `wrap` mode.""" + + ModelWrapSerializerWithoutInfo: TypeAlias = Callable[[Any, SerializerFunctionWrapHandler], Any] + """A model serializer method without the `info` argument, in `wrap` mode.""" + + ModelWrapSerializer: TypeAlias = 'ModelWrapSerializerWithInfo | ModelWrapSerializerWithoutInfo' + """A model serializer method in `wrap` mode.""" + + ModelSerializer: TypeAlias = 'ModelPlainSerializer | ModelWrapSerializer' + + _ModelPlainSerializerT = TypeVar('_ModelPlainSerializerT', bound=ModelPlainSerializer) + _ModelWrapSerializerT = TypeVar('_ModelWrapSerializerT', bound=ModelWrapSerializer) + + +@overload +def model_serializer(f: _ModelPlainSerializerT, /) -> _ModelPlainSerializerT: ... + + +@overload +def model_serializer( + *, mode: Literal['wrap'], when_used: WhenUsed = 'always', return_type: Any = ... +) -> Callable[[_ModelWrapSerializerT], _ModelWrapSerializerT]: ... + + +@overload +def model_serializer( + *, + mode: Literal['plain'] = ..., + when_used: WhenUsed = 'always', + return_type: Any = ..., +) -> Callable[[_ModelPlainSerializerT], _ModelPlainSerializerT]: ... + + +def model_serializer( + f: _ModelPlainSerializerT | _ModelWrapSerializerT | None = None, + /, + *, + mode: Literal['plain', 'wrap'] = 'plain', + when_used: WhenUsed = 'always', + return_type: Any = PydanticUndefined, +) -> ( + _ModelPlainSerializerT + | Callable[[_ModelWrapSerializerT], _ModelWrapSerializerT] + | Callable[[_ModelPlainSerializerT], _ModelPlainSerializerT] +): + """Decorator that enables custom model serialization. + + This is useful when a model need to be serialized in a customized manner, allowing for flexibility beyond just specific fields. + + An example would be to serialize temperature to the same temperature scale, such as degrees Celsius. + + ```python + from typing import Literal + + from pydantic import BaseModel, model_serializer + + class TemperatureModel(BaseModel): + unit: Literal['C', 'F'] + value: int + + @model_serializer() + def serialize_model(self): + if self.unit == 'F': + return {'unit': 'C', 'value': int((self.value - 32) / 1.8)} + return {'unit': self.unit, 'value': self.value} + + temperature = TemperatureModel(unit='F', value=212) + print(temperature.model_dump()) + #> {'unit': 'C', 'value': 100} + ``` + + Two signatures are supported for `mode='plain'`, which is the default: + + - `(self)` + - `(self, info: SerializationInfo)` + + And two other signatures for `mode='wrap'`: + + - `(self, nxt: SerializerFunctionWrapHandler)` + - `(self, nxt: SerializerFunctionWrapHandler, info: SerializationInfo)` + + See [Custom serializers](../concepts/serialization.md#custom-serializers) for more information. + + Args: + f: The function to be decorated. + mode: The serialization mode. + + - `'plain'` means the function will be called instead of the default serialization logic + - `'wrap'` means the function will be called with an argument to optionally call the default + serialization logic. + when_used: Determines when this serializer should be used. + return_type: The return type for the function. If omitted it will be inferred from the type annotation. + + Returns: + The decorator function. + """ + + def dec(f: ModelSerializer) -> _decorators.PydanticDescriptorProxy[Any]: + dec_info = _decorators.ModelSerializerDecoratorInfo(mode=mode, return_type=return_type, when_used=when_used) + return _decorators.PydanticDescriptorProxy(f, dec_info) + + if f is None: + return dec # pyright: ignore[reportReturnType] + else: + return dec(f) # pyright: ignore[reportReturnType] + + +AnyType = TypeVar('AnyType') + + +if TYPE_CHECKING: + SerializeAsAny = Annotated[AnyType, ...] # SerializeAsAny[list[str]] will be treated by type checkers as list[str] + """Force serialization to ignore whatever is defined in the schema and instead ask the object + itself how it should be serialized. + In particular, this means that when model subclasses are serialized, fields present in the subclass + but not in the original schema will be included. + """ +else: + + @dataclasses.dataclass(**_internal_dataclass.slots_true) + class SerializeAsAny: # noqa: D101 + def __class_getitem__(cls, item: Any) -> Any: + return Annotated[item, SerializeAsAny()] + + def __get_pydantic_core_schema__( + self, source_type: Any, handler: GetCoreSchemaHandler + ) -> core_schema.CoreSchema: + schema = handler(source_type) + schema_to_update = schema + while schema_to_update['type'] == 'definitions': + schema_to_update = schema_to_update.copy() + schema_to_update = schema_to_update['schema'] + schema_to_update['serialization'] = core_schema.wrap_serializer_function_ser_schema( + lambda x, h: h(x), schema=core_schema.any_schema() + ) + return schema + + __hash__ = object.__hash__ |