src/attr/__init__.pyi

import sys

from typing import (
    Any,
    Callable,
    Dict,
    Generic,
    List,
    Mapping,
    Optional,
    Sequence,
    Tuple,
    Type,
    TypeVar,
    Union,
    overload,
)

# `import X as X` is required to make these public
from . import converters as converters
from . import exceptions as exceptions
from . import filters as filters
from . import setters as setters
from . import validators as validators
from ._version_info import VersionInfo

__version__: str
__version_info__: VersionInfo
__title__: str
__description__: str
__url__: str
__uri__: str
__author__: str
__email__: str
__license__: str
__copyright__: str

_T = TypeVar("_T")
_C = TypeVar("_C", bound=type)

_EqOrderType = Union[bool, Callable[[Any], Any]]
_ValidatorType = Callable[[Any, Attribute[_T], _T], Any]
_ConverterType = Callable[[Any], Any]
_FilterType = Callable[[Attribute[_T], _T], bool]
_ReprType = Callable[[Any], str]
_ReprArgType = Union[bool, _ReprType]
_OnSetAttrType = Callable[[Any, Attribute[Any], Any], Any]
_OnSetAttrArgType = Union[
    _OnSetAttrType, List[_OnSetAttrType], setters._NoOpType
]
_FieldTransformer = Callable[
    [type, List[Attribute[Any]]], List[Attribute[Any]]
]
_CompareWithType = Callable[[Any, Any], bool]
# FIXME: in reality, if multiple validators are passed they must be in a list
# or tuple, but those are invariant and so would prevent subtypes of
# _ValidatorType from working when passed in a list or tuple.
_ValidatorArgType = Union[_ValidatorType[_T], Sequence[_ValidatorType[_T]]]

# _make --

NOTHING: object

# NOTE: Factory lies about its return type to make this possible:
# `x: List[int] # = Factory(list)`
# Work around mypy issue #4554 in the common case by using an overload.
if sys.version_info >= (3, 8):
    from typing import Literal
    @overload
    def Factory(factory: Callable[[], _T]) -> _T: ...
    @overload
    def Factory(
        factory: Callable[[Any], _T],
        takes_self: Literal[True],
    ) -> _T: ...
    @overload
    def Factory(
        factory: Callable[[], _T],
        takes_self: Literal[False],
    ) -> _T: ...

else:
    @overload
    def Factory(factory: Callable[[], _T]) -> _T: ...
    @overload
    def Factory(
        factory: Union[Callable[[Any], _T], Callable[[], _T]],
        takes_self: bool = ...,
    ) -> _T: ...

# Static type inference support via __dataclass_transform__ implemented as per:
# https://github.com/microsoft/pyright/blob/1.1.135/specs/dataclass_transforms.md
# This annotation must be applied to all overloads of "define" and "attrs"
#
# NOTE: This is a typing construct and does not exist at runtime.  Extensions
# wrapping attrs decorators should declare a separate __dataclass_transform__
# signature in the extension module using the specification linked above to
# provide pyright support.
def __dataclass_transform__(
    *,
    eq_default: bool = True,
    order_default: bool = False,
    kw_only_default: bool = False,
    field_descriptors: Tuple[Union[type, Callable[..., Any]], ...] = (()),
) -> Callable[[_T], _T]: ...

class Attribute(Generic[_T]):
    name: str
    default: Optional[_T]
    validator: Optional[_ValidatorType[_T]]
    repr: _ReprArgType
    cmp: _EqOrderType
    eq: _EqOrderType
    order: _EqOrderType
    hash: Optional[bool]
    init: bool
    converter: Optional[_ConverterType]
    metadata: Dict[Any, Any]
    type: Optional[Type[_T]]
    kw_only: bool
    on_setattr: _OnSetAttrType
    def evolve(self, **changes: Any) -> "Attribute[Any]": ...

# NOTE: We had several choices for the annotation to use for type arg:
# 1) Type[_T]
#   - Pros: Handles simple cases correctly
#   - Cons: Might produce less informative errors in the case of conflicting
#     TypeVars e.g. `attr.ib(default='bad', type=int)`
# 2) Callable[..., _T]
#   - Pros: Better error messages than #1 for conflicting TypeVars
#   - Cons: Terrible error messages for validator checks.
#   e.g. attr.ib(type=int, validator=validate_str)
#        -> error: Cannot infer function type argument
# 3) type (and do all of the work in the mypy plugin)
#   - Pros: Simple here, and we could customize the plugin with our own errors.
#   - Cons: Would need to write mypy plugin code to handle all the cases.
# We chose option #1.

# `attr` lies about its return type to make the following possible:
#     attr()    -> Any
#     attr(8)   -> int
#     attr(validator=<some callable>)  -> Whatever the callable expects.
# This makes this type of assignments possible:
#     x: int = attr(8)
#
# This form catches explicit None or no default but with no other arguments
# returns Any.
@overload
def attrib(
    default: None = ...,
    validator: None = ...,
    repr: _ReprArgType = ...,
    cmp: Optional[_EqOrderType] = ...,
    hash: Optional[bool] = ...,
    init: bool = ...,
    metadata: Optional[Mapping[Any, Any]] = ...,
    type: None = ...,
    converter: None = ...,
    factory: None = ...,
    kw_only: bool = ...,
    eq: Optional[_EqOrderType] = ...,
    order: Optional[_EqOrderType] = ...,
    on_setattr: Optional[_OnSetAttrArgType] = ...,
) -> Any: ...

# This form catches an explicit None or no default and infers the type from the
# other arguments.
@overload
def attrib(
    default: None = ...,
    validator: Optional[_ValidatorArgType[_T]] = ...,
    repr: _ReprArgType = ...,
    cmp: Optional[_EqOrderType] = ...,
    hash: Optional[bool] = ...,
    init: bool = ...,
    metadata: Optional[Mapping[Any, Any]] = ...,
    type: Optional[Type[_T]] = ...,
    converter: Optional[_ConverterType] = ...,
    factory: Optional[Callable[[], _T]] = ...,
    kw_only: bool = ...,
    eq: Optional[_EqOrderType] = ...,
    order: Optional[_EqOrderType] = ...,
    on_setattr: Optional[_OnSetAttrArgType] = ...,
) -> _T: ...

# This form catches an explicit default argument.
@overload
def attrib(
    default: _T,
    validator: Optional[_ValidatorArgType[_T]] = ...,
    repr: _ReprArgType = ...,
    cmp: Optional[_EqOrderType] = ...,
    hash: Optional[bool] = ...,
    init: bool = ...,
    metadata: Optional[Mapping[Any, Any]] = ...,
    type: Optional[Type[_T]] = ...,
    converter: Optional[_ConverterType] = ...,
    factory: Optional[Callable[[], _T]] = ...,
    kw_only: bool = ...,
    eq: Optional[_EqOrderType] = ...,
    order: Optional[_EqOrderType] = ...,
    on_setattr: Optional[_OnSetAttrArgType] = ...,
) -> _T: ...

# This form covers type=non-Type: e.g. forward references (str), Any
@overload
def attrib(
    default: Optional[_T] = ...,
    validator: Optional[_ValidatorArgType[_T]] = ...,
    repr: _ReprArgType = ...,
    cmp: Optional[_EqOrderType] = ...,
    hash: Optional[bool] = ...,
    init: bool = ...,
    metadata: Optional[Mapping[Any, Any]] = ...,
    type: object = ...,
    converter: Optional[_ConverterType] = ...,
    factory: Optional[Callable[[], _T]] = ...,
    kw_only: bool = ...,
    eq: Optional[_EqOrderType] = ...,
    order: Optional[_EqOrderType] = ...,
    on_setattr: Optional[_OnSetAttrArgType] = ...,
) -> Any: ...
@overload
def field(
    *,
    default: None = ...,
    validator: None = ...,
    repr: _ReprArgType = ...,
    hash: Optional[bool] = ...,
    init: bool = ...,
    metadata: Optional[Mapping[Any, Any]] = ...,
    converter: None = ...,
    factory: None = ...,
    kw_only: bool = ...,
    eq: Optional[bool] = ...,
    order: Optional[bool] = ...,
    on_setattr: Optional[_OnSetAttrArgType] = ...,
) -> Any: ...

# This form catches an explicit None or no default and infers the type from the
# other arguments.
@overload
def field(
    *,
    default: None = ...,
    validator: Optional[_ValidatorArgType[_T]] = ...,
    repr: _ReprArgType = ...,
    hash: Optional[bool] = ...,
    init: bool = ...,
    metadata: Optional[Mapping[Any, Any]] = ...,
    converter: Optional[_ConverterType] = ...,
    factory: Optional[Callable[[], _T]] = ...,
    kw_only: bool = ...,
    eq: Optional[_EqOrderType] = ...,
    order: Optional[_EqOrderType] = ...,
    on_setattr: Optional[_OnSetAttrArgType] = ...,
) -> _T: ...

# This form catches an explicit default argument.
@overload
def field(
    *,
    default: _T,
    validator: Optional[_ValidatorArgType[_T]] = ...,
    repr: _ReprArgType = ...,
    hash: Optional[bool] = ...,
    init: bool = ...,
    metadata: Optional[Mapping[Any, Any]] = ...,
    converter: Optional[_ConverterType] = ...,
    factory: Optional[Callable[[], _T]] = ...,
    kw_only: bool = ...,
    eq: Optional[_EqOrderType] = ...,
    order: Optional[_EqOrderType] = ...,
    on_setattr: Optional[_OnSetAttrArgType] = ...,
) -> _T: ...

# This form covers type=non-Type: e.g. forward references (str), Any
@overload
def field(
    *,
    default: Optional[_T] = ...,
    validator: Optional[_ValidatorArgType[_T]] = ...,
    repr: _ReprArgType = ...,
    hash: Optional[bool] = ...,
    init: bool = ...,
    metadata: Optional[Mapping[Any, Any]] = ...,
    converter: Optional[_ConverterType] = ...,
    factory: Optional[Callable[[], _T]] = ...,
    kw_only: bool = ...,
    eq: Optional[_EqOrderType] = ...,
    order: Optional[_EqOrderType] = ...,
    on_setattr: Optional[_OnSetAttrArgType] = ...,
) -> Any: ...
@overload
@__dataclass_transform__(order_default=True, field_descriptors=(attrib, field))
def attrs(
    maybe_cls: _C,
    these: Optional[Dict[str, Any]] = ...,
    repr_ns: Optional[str] = ...,
    repr: bool = ...,
    cmp: Optional[_EqOrderType] = ...,
    hash: Optional[bool] = ...,
    init: bool = ...,
    slots: bool = ...,
    frozen: bool = ...,
    weakref_slot: bool = ...,
    str: bool = ...,
    auto_attribs: bool = ...,
    kw_only: bool = ...,
    cache_hash: bool = ...,
    auto_exc: bool = ...,
    eq: Optional[_EqOrderType] = ...,
    order: Optional[_EqOrderType] = ...,
    auto_detect: bool = ...,
    collect_by_mro: bool = ...,
    getstate_setstate: Optional[bool] = ...,
    on_setattr: Optional[_OnSetAttrArgType] = ...,
    field_transformer: Optional[_FieldTransformer] = ...,
    match_args: bool = ...,
) -> _C: ...
@overload
@__dataclass_transform__(order_default=True, field_descriptors=(attrib, field))
def attrs(
    maybe_cls: None = ...,
    these: Optional[Dict[str, Any]] = ...,
    repr_ns: Optional[str] = ...,
    repr: bool = ...,
    cmp: Optional[_EqOrderType] = ...,
    hash: Optional[bool] = ...,
    init: bool = ...,
    slots: bool = ...,
    frozen: bool = ...,
    weakref_slot: bool = ...,
    str: bool = ...,
    auto_attribs: bool = ...,
    kw_only: bool = ...,
    cache_hash: bool = ...,
    auto_exc: bool = ...,
    eq: Optional[_EqOrderType] = ...,
    order: Optional[_EqOrderType] = ...,
    auto_detect: bool = ...,
    collect_by_mro: bool = ...,
    getstate_setstate: Optional[bool] = ...,
    on_setattr: Optional[_OnSetAttrArgType] = ...,
    field_transformer: Optional[_FieldTransformer] = ...,
    match_args: bool = ...,
) -> Callable[[_C], _C]: ...
@overload
@__dataclass_transform__(field_descriptors=(attrib, field))
def define(
    maybe_cls: _C,
    *,
    these: Optional[Dict[str, Any]] = ...,
    repr: bool = ...,
    hash: Optional[bool] = ...,
    init: bool = ...,
    slots: bool = ...,
    frozen: bool = ...,
    weakref_slot: bool = ...,
    str: bool = ...,
    auto_attribs: bool = ...,
    kw_only: bool = ...,
    cache_hash: bool = ...,
    auto_exc: bool = ...,
    eq: Optional[bool] = ...,
    order: Optional[bool] = ...,
    auto_detect: bool = ...,
    getstate_setstate: Optional[bool] = ...,
    on_setattr: Optional[_OnSetAttrArgType] = ...,
    field_transformer: Optional[_FieldTransformer] = ...,
    match_args: bool = ...,
) -> _C: ...
@overload
@__dataclass_transform__(field_descriptors=(attrib, field))
def define(
    maybe_cls: None = ...,
    *,
    these: Optional[Dict[str, Any]] = ...,
    repr: bool = ...,
    hash: Optional[bool] = ...,
    init: bool = ...,
    slots: bool = ...,
    frozen: bool = ...,
    weakref_slot: bool = ...,
    str: bool = ...,
    auto_attribs: bool = ...,
    kw_only: bool = ...,
    cache_hash: bool = ...,
    auto_exc: bool = ...,
    eq: Optional[bool] = ...,
    order: Optional[bool] = ...,
    auto_detect: bool = ...,
    getstate_setstate: Optional[bool] = ...,
    on_setattr: Optional[_OnSetAttrArgType] = ...,
    field_transformer: Optional[_FieldTransformer] = ...,
    match_args: bool = ...,
) -> Callable[[_C], _C]: ...

mutable = define
frozen = define  # they differ only in their defaults

# TODO: add support for returning NamedTuple from the mypy plugin
class _Fields(Tuple[Attribute[Any], ...]):
    def __getattr__(self, name: str) -> Attribute[Any]: ...

def fields(cls: type) -> _Fields: ...
def fields_dict(cls: type) -> Dict[str, Attribute[Any]]: ...
def validate(inst: Any) -> None: ...
def resolve_types(
    cls: _C,
    globalns: Optional[Dict[str, Any]] = ...,
    localns: Optional[Dict[str, Any]] = ...,
    attribs: Optional[List[Attribute[Any]]] = ...,
) -> _C: ...

# TODO: add support for returning a proper attrs class from the mypy plugin
# we use Any instead of _CountingAttr so that e.g. `make_class('Foo',
# [attr.ib()])` is valid
def make_class(
    name: str,
    attrs: Union[List[str], Tuple[str, ...], Dict[str, Any]],
    bases: Tuple[type, ...] = ...,
    repr_ns: Optional[str] = ...,
    repr: bool = ...,
    cmp: Optional[_EqOrderType] = ...,
    hash: Optional[bool] = ...,
    init: bool = ...,
    slots: bool = ...,
    frozen: bool = ...,
    weakref_slot: bool = ...,
    str: bool = ...,
    auto_attribs: bool = ...,
    kw_only: bool = ...,
    cache_hash: bool = ...,
    auto_exc: bool = ...,
    eq: Optional[_EqOrderType] = ...,
    order: Optional[_EqOrderType] = ...,
    collect_by_mro: bool = ...,
    on_setattr: Optional[_OnSetAttrArgType] = ...,
    field_transformer: Optional[_FieldTransformer] = ...,
) -> type: ...

# _funcs --

# TODO: add support for returning TypedDict from the mypy plugin
# FIXME: asdict/astuple do not honor their factory args. Waiting on one of
# these:
# https://github.com/python/mypy/issues/4236
# https://github.com/python/typing/issues/253
# XXX: remember to fix attrs.asdict/astuple too!
def asdict(
    inst: Any,
    recurse: bool = ...,
    filter: Optional[_FilterType[Any]] = ...,
    dict_factory: Type[Mapping[Any, Any]] = ...,
    retain_collection_types: bool = ...,
    value_serializer: Optional[
        Callable[[type, Attribute[Any], Any], Any]
    ] = ...,
    tuple_keys: Optional[bool] = ...,
) -> Dict[str, Any]: ...

# TODO: add support for returning NamedTuple from the mypy plugin
def astuple(
    inst: Any,
    recurse: bool = ...,
    filter: Optional[_FilterType[Any]] = ...,
    tuple_factory: Type[Sequence[Any]] = ...,
    retain_collection_types: bool = ...,
) -> Tuple[Any, ...]: ...
def has(cls: type) -> bool: ...
def assoc(inst: _T, **changes: Any) -> _T: ...
def evolve(inst: _T, **changes: Any) -> _T: ...

# _config --

def set_run_validators(run: bool) -> None: ...
def get_run_validators() -> bool: ...

# aliases --

s = attributes = attrs
ib = attr = attrib
dataclass = attrs  # Technically, partial(attrs, auto_attribs=True) ;)