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- # util/typing.py
- # Copyright (C) 2022-2024 the SQLAlchemy authors and contributors
- # <see AUTHORS file>
- #
- # This module is part of SQLAlchemy and is released under
- # the MIT License: https://www.opensource.org/licenses/mit-license.php
- # mypy: allow-untyped-defs, allow-untyped-calls
- from __future__ import annotations
- import builtins
- import collections.abc as collections_abc
- import re
- import sys
- import typing
- from typing import Any
- from typing import Callable
- from typing import cast
- from typing import Dict
- from typing import ForwardRef
- from typing import Generic
- from typing import Iterable
- from typing import Mapping
- from typing import NewType
- from typing import NoReturn
- from typing import Optional
- from typing import overload
- from typing import Set
- from typing import Tuple
- from typing import Type
- from typing import TYPE_CHECKING
- from typing import TypeVar
- from typing import Union
- from . import compat
- if True: # zimports removes the tailing comments
- from typing_extensions import Annotated as Annotated # 3.8
- from typing_extensions import Concatenate as Concatenate # 3.10
- from typing_extensions import (
- dataclass_transform as dataclass_transform, # 3.11,
- )
- from typing_extensions import Final as Final # 3.8
- from typing_extensions import final as final # 3.8
- from typing_extensions import get_args as get_args # 3.10
- from typing_extensions import get_origin as get_origin # 3.10
- from typing_extensions import Literal as Literal # 3.8
- from typing_extensions import NotRequired as NotRequired # 3.11
- from typing_extensions import ParamSpec as ParamSpec # 3.10
- from typing_extensions import Protocol as Protocol # 3.8
- from typing_extensions import SupportsIndex as SupportsIndex # 3.8
- from typing_extensions import TypeAlias as TypeAlias # 3.10
- from typing_extensions import TypedDict as TypedDict # 3.8
- from typing_extensions import TypeGuard as TypeGuard # 3.10
- from typing_extensions import Self as Self # 3.11
- from typing_extensions import TypeAliasType as TypeAliasType # 3.12
- _T = TypeVar("_T", bound=Any)
- _KT = TypeVar("_KT")
- _KT_co = TypeVar("_KT_co", covariant=True)
- _KT_contra = TypeVar("_KT_contra", contravariant=True)
- _VT = TypeVar("_VT")
- _VT_co = TypeVar("_VT_co", covariant=True)
- if compat.py310:
- # why they took until py310 to put this in stdlib is beyond me,
- # I've been wanting it since py27
- from types import NoneType as NoneType
- else:
- NoneType = type(None) # type: ignore
- NoneFwd = ForwardRef("None")
- typing_get_args = get_args
- typing_get_origin = get_origin
- _AnnotationScanType = Union[
- Type[Any], str, ForwardRef, NewType, TypeAliasType, "GenericProtocol[Any]"
- ]
- class ArgsTypeProcotol(Protocol):
- """protocol for types that have ``__args__``
- there's no public interface for this AFAIK
- """
- __args__: Tuple[_AnnotationScanType, ...]
- class GenericProtocol(Protocol[_T]):
- """protocol for generic types.
- this since Python.typing _GenericAlias is private
- """
- __args__: Tuple[_AnnotationScanType, ...]
- __origin__: Type[_T]
- # Python's builtin _GenericAlias has this method, however builtins like
- # list, dict, etc. do not, even though they have ``__origin__`` and
- # ``__args__``
- #
- # def copy_with(self, params: Tuple[_AnnotationScanType, ...]) -> Type[_T]:
- # ...
- # copied from TypeShed, required in order to implement
- # MutableMapping.update()
- class SupportsKeysAndGetItem(Protocol[_KT, _VT_co]):
- def keys(self) -> Iterable[_KT]:
- ...
- def __getitem__(self, __k: _KT) -> _VT_co:
- ...
- # work around https://github.com/microsoft/pyright/issues/3025
- _LiteralStar = Literal["*"]
- def de_stringify_annotation(
- cls: Type[Any],
- annotation: _AnnotationScanType,
- originating_module: str,
- locals_: Mapping[str, Any],
- *,
- str_cleanup_fn: Optional[Callable[[str, str], str]] = None,
- include_generic: bool = False,
- _already_seen: Optional[Set[Any]] = None,
- ) -> Type[Any]:
- """Resolve annotations that may be string based into real objects.
- This is particularly important if a module defines "from __future__ import
- annotations", as everything inside of __annotations__ is a string. We want
- to at least have generic containers like ``Mapped``, ``Union``, ``List``,
- etc.
- """
- # looked at typing.get_type_hints(), looked at pydantic. We need much
- # less here, and we here try to not use any private typing internals
- # or construct ForwardRef objects which is documented as something
- # that should be avoided.
- original_annotation = annotation
- if is_fwd_ref(annotation):
- annotation = annotation.__forward_arg__
- if isinstance(annotation, str):
- if str_cleanup_fn:
- annotation = str_cleanup_fn(annotation, originating_module)
- annotation = eval_expression(
- annotation, originating_module, locals_=locals_
- )
- if (
- include_generic
- and is_generic(annotation)
- and not is_literal(annotation)
- ):
- if _already_seen is None:
- _already_seen = set()
- if annotation in _already_seen:
- # only occurs recursively. outermost return type
- # will always be Type.
- # the element here will be either ForwardRef or
- # Optional[ForwardRef]
- return original_annotation # type: ignore
- else:
- _already_seen.add(annotation)
- elements = tuple(
- de_stringify_annotation(
- cls,
- elem,
- originating_module,
- locals_,
- str_cleanup_fn=str_cleanup_fn,
- include_generic=include_generic,
- _already_seen=_already_seen,
- )
- for elem in annotation.__args__
- )
- return _copy_generic_annotation_with(annotation, elements)
- return annotation # type: ignore
- def _copy_generic_annotation_with(
- annotation: GenericProtocol[_T], elements: Tuple[_AnnotationScanType, ...]
- ) -> Type[_T]:
- if hasattr(annotation, "copy_with"):
- # List, Dict, etc. real generics
- return annotation.copy_with(elements) # type: ignore
- else:
- # Python builtins list, dict, etc.
- return annotation.__origin__[elements] # type: ignore
- def eval_expression(
- expression: str,
- module_name: str,
- *,
- locals_: Optional[Mapping[str, Any]] = None,
- ) -> Any:
- try:
- base_globals: Dict[str, Any] = sys.modules[module_name].__dict__
- except KeyError as ke:
- raise NameError(
- f"Module {module_name} isn't present in sys.modules; can't "
- f"evaluate expression {expression}"
- ) from ke
- try:
- annotation = eval(expression, base_globals, locals_)
- except Exception as err:
- raise NameError(
- f"Could not de-stringify annotation {expression!r}"
- ) from err
- else:
- return annotation
- def eval_name_only(
- name: str,
- module_name: str,
- *,
- locals_: Optional[Mapping[str, Any]] = None,
- ) -> Any:
- if "." in name:
- return eval_expression(name, module_name, locals_=locals_)
- try:
- base_globals: Dict[str, Any] = sys.modules[module_name].__dict__
- except KeyError as ke:
- raise NameError(
- f"Module {module_name} isn't present in sys.modules; can't "
- f"resolve name {name}"
- ) from ke
- # name only, just look in globals. eval() works perfectly fine here,
- # however we are seeking to have this be faster, as this occurs for
- # every Mapper[] keyword, etc. depending on configuration
- try:
- return base_globals[name]
- except KeyError as ke:
- # check in builtins as well to handle `list`, `set` or `dict`, etc.
- try:
- return builtins.__dict__[name]
- except KeyError:
- pass
- raise NameError(
- f"Could not locate name {name} in module {module_name}"
- ) from ke
- def resolve_name_to_real_class_name(name: str, module_name: str) -> str:
- try:
- obj = eval_name_only(name, module_name)
- except NameError:
- return name
- else:
- return getattr(obj, "__name__", name)
- def de_stringify_union_elements(
- cls: Type[Any],
- annotation: ArgsTypeProcotol,
- originating_module: str,
- locals_: Mapping[str, Any],
- *,
- str_cleanup_fn: Optional[Callable[[str, str], str]] = None,
- ) -> Type[Any]:
- return make_union_type(
- *[
- de_stringify_annotation(
- cls,
- anno,
- originating_module,
- {},
- str_cleanup_fn=str_cleanup_fn,
- )
- for anno in annotation.__args__
- ]
- )
- def is_pep593(type_: Optional[_AnnotationScanType]) -> bool:
- return type_ is not None and typing_get_origin(type_) is Annotated
- def is_non_string_iterable(obj: Any) -> TypeGuard[Iterable[Any]]:
- return isinstance(obj, collections_abc.Iterable) and not isinstance(
- obj, (str, bytes)
- )
- def is_literal(type_: _AnnotationScanType) -> bool:
- return get_origin(type_) is Literal
- def is_newtype(type_: Optional[_AnnotationScanType]) -> TypeGuard[NewType]:
- return hasattr(type_, "__supertype__")
- # doesn't work in 3.8, 3.7 as it passes a closure, not an
- # object instance
- # return isinstance(type_, NewType)
- def is_generic(type_: _AnnotationScanType) -> TypeGuard[GenericProtocol[Any]]:
- return hasattr(type_, "__args__") and hasattr(type_, "__origin__")
- def is_pep695(type_: _AnnotationScanType) -> TypeGuard[TypeAliasType]:
- return isinstance(type_, TypeAliasType)
- def flatten_newtype(type_: NewType) -> Type[Any]:
- super_type = type_.__supertype__
- while is_newtype(super_type):
- super_type = super_type.__supertype__
- return super_type
- def is_fwd_ref(
- type_: _AnnotationScanType, check_generic: bool = False
- ) -> TypeGuard[ForwardRef]:
- if isinstance(type_, ForwardRef):
- return True
- elif check_generic and is_generic(type_):
- return any(is_fwd_ref(arg, True) for arg in type_.__args__)
- else:
- return False
- @overload
- def de_optionalize_union_types(type_: str) -> str:
- ...
- @overload
- def de_optionalize_union_types(type_: Type[Any]) -> Type[Any]:
- ...
- @overload
- def de_optionalize_union_types(
- type_: _AnnotationScanType,
- ) -> _AnnotationScanType:
- ...
- def de_optionalize_union_types(
- type_: _AnnotationScanType,
- ) -> _AnnotationScanType:
- """Given a type, filter out ``Union`` types that include ``NoneType``
- to not include the ``NoneType``.
- """
- if is_fwd_ref(type_):
- return de_optionalize_fwd_ref_union_types(type_)
- elif is_optional(type_):
- typ = set(type_.__args__)
- typ.discard(NoneType)
- typ.discard(NoneFwd)
- return make_union_type(*typ)
- else:
- return type_
- def de_optionalize_fwd_ref_union_types(
- type_: ForwardRef,
- ) -> _AnnotationScanType:
- """return the non-optional type for Optional[], Union[None, ...], x|None,
- etc. without de-stringifying forward refs.
- unfortunately this seems to require lots of hardcoded heuristics
- """
- annotation = type_.__forward_arg__
- mm = re.match(r"^(.+?)\[(.+)\]$", annotation)
- if mm:
- if mm.group(1) == "Optional":
- return ForwardRef(mm.group(2))
- elif mm.group(1) == "Union":
- elements = re.split(r",\s*", mm.group(2))
- return make_union_type(
- *[ForwardRef(elem) for elem in elements if elem != "None"]
- )
- else:
- return type_
- pipe_tokens = re.split(r"\s*\|\s*", annotation)
- if "None" in pipe_tokens:
- return ForwardRef("|".join(p for p in pipe_tokens if p != "None"))
- return type_
- def make_union_type(*types: _AnnotationScanType) -> Type[Any]:
- """Make a Union type.
- This is needed by :func:`.de_optionalize_union_types` which removes
- ``NoneType`` from a ``Union``.
- """
- return cast(Any, Union).__getitem__(types) # type: ignore
- def expand_unions(
- type_: Type[Any], include_union: bool = False, discard_none: bool = False
- ) -> Tuple[Type[Any], ...]:
- """Return a type as a tuple of individual types, expanding for
- ``Union`` types."""
- if is_union(type_):
- typ = set(type_.__args__)
- if discard_none:
- typ.discard(NoneType)
- if include_union:
- return (type_,) + tuple(typ) # type: ignore
- else:
- return tuple(typ) # type: ignore
- else:
- return (type_,)
- def is_optional(type_: Any) -> TypeGuard[ArgsTypeProcotol]:
- return is_origin_of(
- type_,
- "Optional",
- "Union",
- "UnionType",
- )
- def is_optional_union(type_: Any) -> bool:
- return is_optional(type_) and NoneType in typing_get_args(type_)
- def is_union(type_: Any) -> TypeGuard[ArgsTypeProcotol]:
- return is_origin_of(type_, "Union")
- def is_origin_of_cls(
- type_: Any, class_obj: Union[Tuple[Type[Any], ...], Type[Any]]
- ) -> bool:
- """return True if the given type has an __origin__ that shares a base
- with the given class"""
- origin = typing_get_origin(type_)
- if origin is None:
- return False
- return isinstance(origin, type) and issubclass(origin, class_obj)
- def is_origin_of(
- type_: Any, *names: str, module: Optional[str] = None
- ) -> bool:
- """return True if the given type has an __origin__ with the given name
- and optional module."""
- origin = typing_get_origin(type_)
- if origin is None:
- return False
- return _get_type_name(origin) in names and (
- module is None or origin.__module__.startswith(module)
- )
- def _get_type_name(type_: Type[Any]) -> str:
- if compat.py310:
- return type_.__name__
- else:
- typ_name = getattr(type_, "__name__", None)
- if typ_name is None:
- typ_name = getattr(type_, "_name", None)
- return typ_name # type: ignore
- class DescriptorProto(Protocol):
- def __get__(self, instance: object, owner: Any) -> Any:
- ...
- def __set__(self, instance: Any, value: Any) -> None:
- ...
- def __delete__(self, instance: Any) -> None:
- ...
- _DESC = TypeVar("_DESC", bound=DescriptorProto)
- class DescriptorReference(Generic[_DESC]):
- """a descriptor that refers to a descriptor.
- used for cases where we need to have an instance variable referring to an
- object that is itself a descriptor, which typically confuses typing tools
- as they don't know when they should use ``__get__`` or not when referring
- to the descriptor assignment as an instance variable. See
- sqlalchemy.orm.interfaces.PropComparator.prop
- """
- if TYPE_CHECKING:
- def __get__(self, instance: object, owner: Any) -> _DESC:
- ...
- def __set__(self, instance: Any, value: _DESC) -> None:
- ...
- def __delete__(self, instance: Any) -> None:
- ...
- _DESC_co = TypeVar("_DESC_co", bound=DescriptorProto, covariant=True)
- class RODescriptorReference(Generic[_DESC_co]):
- """a descriptor that refers to a descriptor.
- same as :class:`.DescriptorReference` but is read-only, so that subclasses
- can define a subtype as the generically contained element
- """
- if TYPE_CHECKING:
- def __get__(self, instance: object, owner: Any) -> _DESC_co:
- ...
- def __set__(self, instance: Any, value: Any) -> NoReturn:
- ...
- def __delete__(self, instance: Any) -> NoReturn:
- ...
- _FN = TypeVar("_FN", bound=Optional[Callable[..., Any]])
- class CallableReference(Generic[_FN]):
- """a descriptor that refers to a callable.
- works around mypy's limitation of not allowing callables assigned
- as instance variables
- """
- if TYPE_CHECKING:
- def __get__(self, instance: object, owner: Any) -> _FN:
- ...
- def __set__(self, instance: Any, value: _FN) -> None:
- ...
- def __delete__(self, instance: Any) -> None:
- ...
- # $def ro_descriptor_reference(fn: Callable[])
|