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Diffstat (limited to '.venv/lib/python3.12/site-packages/attr/_make.py')
| -rw-r--r-- | .venv/lib/python3.12/site-packages/attr/_make.py | 3123 |
1 files changed, 3123 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/attr/_make.py b/.venv/lib/python3.12/site-packages/attr/_make.py new file mode 100644 index 00000000..e84d9792 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/attr/_make.py @@ -0,0 +1,3123 @@ +# SPDX-License-Identifier: MIT + +from __future__ import annotations + +import abc +import contextlib +import copy +import enum +import inspect +import itertools +import linecache +import sys +import types +import unicodedata + +from collections.abc import Callable, Mapping +from functools import cached_property +from typing import Any, NamedTuple, TypeVar + +# We need to import _compat itself in addition to the _compat members to avoid +# having the thread-local in the globals here. +from . import _compat, _config, setters +from ._compat import ( + PY_3_10_PLUS, + PY_3_11_PLUS, + PY_3_13_PLUS, + _AnnotationExtractor, + _get_annotations, + get_generic_base, +) +from .exceptions import ( + DefaultAlreadySetError, + FrozenInstanceError, + NotAnAttrsClassError, + UnannotatedAttributeError, +) + + +# This is used at least twice, so cache it here. +_OBJ_SETATTR = object.__setattr__ +_INIT_FACTORY_PAT = "__attr_factory_%s" +_CLASSVAR_PREFIXES = ( + "typing.ClassVar", + "t.ClassVar", + "ClassVar", + "typing_extensions.ClassVar", +) +# we don't use a double-underscore prefix because that triggers +# name mangling when trying to create a slot for the field +# (when slots=True) +_HASH_CACHE_FIELD = "_attrs_cached_hash" + +_EMPTY_METADATA_SINGLETON = types.MappingProxyType({}) + +# Unique object for unequivocal getattr() defaults. +_SENTINEL = object() + +_DEFAULT_ON_SETATTR = setters.pipe(setters.convert, setters.validate) + + +class _Nothing(enum.Enum): + """ + Sentinel to indicate the lack of a value when `None` is ambiguous. + + If extending attrs, you can use ``typing.Literal[NOTHING]`` to show + that a value may be ``NOTHING``. + + .. versionchanged:: 21.1.0 ``bool(NOTHING)`` is now False. + .. versionchanged:: 22.2.0 ``NOTHING`` is now an ``enum.Enum`` variant. + """ + + NOTHING = enum.auto() + + def __repr__(self): + return "NOTHING" + + def __bool__(self): + return False + + +NOTHING = _Nothing.NOTHING +""" +Sentinel to indicate the lack of a value when `None` is ambiguous. + +When using in 3rd party code, use `attrs.NothingType` for type annotations. +""" + + +class _CacheHashWrapper(int): + """ + An integer subclass that pickles / copies as None + + This is used for non-slots classes with ``cache_hash=True``, to avoid + serializing a potentially (even likely) invalid hash value. Since `None` + is the default value for uncalculated hashes, whenever this is copied, + the copy's value for the hash should automatically reset. + + See GH #613 for more details. + """ + + def __reduce__(self, _none_constructor=type(None), _args=()): # noqa: B008 + return _none_constructor, _args + + +def attrib( + default=NOTHING, + validator=None, + repr=True, + cmp=None, + hash=None, + init=True, + metadata=None, + type=None, + converter=None, + factory=None, + kw_only=False, + eq=None, + order=None, + on_setattr=None, + alias=None, +): + """ + Create a new field / attribute on a class. + + Identical to `attrs.field`, except it's not keyword-only. + + Consider using `attrs.field` in new code (``attr.ib`` will *never* go away, + though). + + .. warning:: + + Does **nothing** unless the class is also decorated with + `attr.s` (or similar)! + + + .. versionadded:: 15.2.0 *convert* + .. versionadded:: 16.3.0 *metadata* + .. versionchanged:: 17.1.0 *validator* can be a ``list`` now. + .. versionchanged:: 17.1.0 + *hash* is `None` and therefore mirrors *eq* by default. + .. versionadded:: 17.3.0 *type* + .. deprecated:: 17.4.0 *convert* + .. versionadded:: 17.4.0 + *converter* as a replacement for the deprecated *convert* to achieve + consistency with other noun-based arguments. + .. versionadded:: 18.1.0 + ``factory=f`` is syntactic sugar for ``default=attr.Factory(f)``. + .. versionadded:: 18.2.0 *kw_only* + .. versionchanged:: 19.2.0 *convert* keyword argument removed. + .. versionchanged:: 19.2.0 *repr* also accepts a custom callable. + .. deprecated:: 19.2.0 *cmp* Removal on or after 2021-06-01. + .. versionadded:: 19.2.0 *eq* and *order* + .. versionadded:: 20.1.0 *on_setattr* + .. versionchanged:: 20.3.0 *kw_only* backported to Python 2 + .. versionchanged:: 21.1.0 + *eq*, *order*, and *cmp* also accept a custom callable + .. versionchanged:: 21.1.0 *cmp* undeprecated + .. versionadded:: 22.2.0 *alias* + """ + eq, eq_key, order, order_key = _determine_attrib_eq_order( + cmp, eq, order, True + ) + + if hash is not None and hash is not True and hash is not False: + msg = "Invalid value for hash. Must be True, False, or None." + raise TypeError(msg) + + if factory is not None: + if default is not NOTHING: + msg = ( + "The `default` and `factory` arguments are mutually exclusive." + ) + raise ValueError(msg) + if not callable(factory): + msg = "The `factory` argument must be a callable." + raise ValueError(msg) + default = Factory(factory) + + if metadata is None: + metadata = {} + + # Apply syntactic sugar by auto-wrapping. + if isinstance(on_setattr, (list, tuple)): + on_setattr = setters.pipe(*on_setattr) + + if validator and isinstance(validator, (list, tuple)): + validator = and_(*validator) + + if converter and isinstance(converter, (list, tuple)): + converter = pipe(*converter) + + return _CountingAttr( + default=default, + validator=validator, + repr=repr, + cmp=None, + hash=hash, + init=init, + converter=converter, + metadata=metadata, + type=type, + kw_only=kw_only, + eq=eq, + eq_key=eq_key, + order=order, + order_key=order_key, + on_setattr=on_setattr, + alias=alias, + ) + + +def _compile_and_eval( + script: str, + globs: dict[str, Any] | None, + locs: Mapping[str, object] | None = None, + filename: str = "", +) -> None: + """ + Evaluate the script with the given global (globs) and local (locs) + variables. + """ + bytecode = compile(script, filename, "exec") + eval(bytecode, globs, locs) + + +def _linecache_and_compile( + script: str, + filename: str, + globs: dict[str, Any] | None, + locals: Mapping[str, object] | None = None, +) -> dict[str, Any]: + """ + Cache the script with _linecache_, compile it and return the _locals_. + """ + + locs = {} if locals is None else locals + + # In order of debuggers like PDB being able to step through the code, + # we add a fake linecache entry. + count = 1 + base_filename = filename + while True: + linecache_tuple = ( + len(script), + None, + script.splitlines(True), + filename, + ) + old_val = linecache.cache.setdefault(filename, linecache_tuple) + if old_val == linecache_tuple: + break + + filename = f"{base_filename[:-1]}-{count}>" + count += 1 + + _compile_and_eval(script, globs, locs, filename) + + return locs + + +def _make_attr_tuple_class(cls_name: str, attr_names: list[str]) -> type: + """ + Create a tuple subclass to hold `Attribute`s for an `attrs` class. + + The subclass is a bare tuple with properties for names. + + class MyClassAttributes(tuple): + __slots__ = () + x = property(itemgetter(0)) + """ + attr_class_name = f"{cls_name}Attributes" + body = {} + for i, attr_name in enumerate(attr_names): + + def getter(self, i=i): + return self[i] + + body[attr_name] = property(getter) + return type(attr_class_name, (tuple,), body) + + +# Tuple class for extracted attributes from a class definition. +# `base_attrs` is a subset of `attrs`. +class _Attributes(NamedTuple): + attrs: type + base_attrs: list[Attribute] + base_attrs_map: dict[str, type] + + +def _is_class_var(annot): + """ + Check whether *annot* is a typing.ClassVar. + + The string comparison hack is used to avoid evaluating all string + annotations which would put attrs-based classes at a performance + disadvantage compared to plain old classes. + """ + annot = str(annot) + + # Annotation can be quoted. + if annot.startswith(("'", '"')) and annot.endswith(("'", '"')): + annot = annot[1:-1] + + return annot.startswith(_CLASSVAR_PREFIXES) + + +def _has_own_attribute(cls, attrib_name): + """ + Check whether *cls* defines *attrib_name* (and doesn't just inherit it). + """ + return attrib_name in cls.__dict__ + + +def _collect_base_attrs( + cls, taken_attr_names +) -> tuple[list[Attribute], dict[str, type]]: + """ + Collect attr.ibs from base classes of *cls*, except *taken_attr_names*. + """ + base_attrs = [] + base_attr_map = {} # A dictionary of base attrs to their classes. + + # Traverse the MRO and collect attributes. + for base_cls in reversed(cls.__mro__[1:-1]): + for a in getattr(base_cls, "__attrs_attrs__", []): + if a.inherited or a.name in taken_attr_names: + continue + + a = a.evolve(inherited=True) # noqa: PLW2901 + base_attrs.append(a) + base_attr_map[a.name] = base_cls + + # For each name, only keep the freshest definition i.e. the furthest at the + # back. base_attr_map is fine because it gets overwritten with every new + # instance. + filtered = [] + seen = set() + for a in reversed(base_attrs): + if a.name in seen: + continue + filtered.insert(0, a) + seen.add(a.name) + + return filtered, base_attr_map + + +def _collect_base_attrs_broken(cls, taken_attr_names): + """ + Collect attr.ibs from base classes of *cls*, except *taken_attr_names*. + + N.B. *taken_attr_names* will be mutated. + + Adhere to the old incorrect behavior. + + Notably it collects from the front and considers inherited attributes which + leads to the buggy behavior reported in #428. + """ + base_attrs = [] + base_attr_map = {} # A dictionary of base attrs to their classes. + + # Traverse the MRO and collect attributes. + for base_cls in cls.__mro__[1:-1]: + for a in getattr(base_cls, "__attrs_attrs__", []): + if a.name in taken_attr_names: + continue + + a = a.evolve(inherited=True) # noqa: PLW2901 + taken_attr_names.add(a.name) + base_attrs.append(a) + base_attr_map[a.name] = base_cls + + return base_attrs, base_attr_map + + +def _transform_attrs( + cls, these, auto_attribs, kw_only, collect_by_mro, field_transformer +) -> _Attributes: + """ + Transform all `_CountingAttr`s on a class into `Attribute`s. + + If *these* is passed, use that and don't look for them on the class. + + If *collect_by_mro* is True, collect them in the correct MRO order, + otherwise use the old -- incorrect -- order. See #428. + + Return an `_Attributes`. + """ + cd = cls.__dict__ + anns = _get_annotations(cls) + + if these is not None: + ca_list = list(these.items()) + elif auto_attribs is True: + ca_names = { + name + for name, attr in cd.items() + if attr.__class__ is _CountingAttr + } + ca_list = [] + annot_names = set() + for attr_name, type in anns.items(): + if _is_class_var(type): + continue + annot_names.add(attr_name) + a = cd.get(attr_name, NOTHING) + + if a.__class__ is not _CountingAttr: + a = attrib(a) + ca_list.append((attr_name, a)) + + unannotated = ca_names - annot_names + if unannotated: + raise UnannotatedAttributeError( + "The following `attr.ib`s lack a type annotation: " + + ", ".join( + sorted(unannotated, key=lambda n: cd.get(n).counter) + ) + + "." + ) + else: + ca_list = sorted( + ( + (name, attr) + for name, attr in cd.items() + if attr.__class__ is _CountingAttr + ), + key=lambda e: e[1].counter, + ) + + fca = Attribute.from_counting_attr + own_attrs = [ + fca(attr_name, ca, anns.get(attr_name)) for attr_name, ca in ca_list + ] + + if collect_by_mro: + base_attrs, base_attr_map = _collect_base_attrs( + cls, {a.name for a in own_attrs} + ) + else: + base_attrs, base_attr_map = _collect_base_attrs_broken( + cls, {a.name for a in own_attrs} + ) + + if kw_only: + own_attrs = [a.evolve(kw_only=True) for a in own_attrs] + base_attrs = [a.evolve(kw_only=True) for a in base_attrs] + + attrs = base_attrs + own_attrs + + if field_transformer is not None: + attrs = tuple(field_transformer(cls, attrs)) + + # Check attr order after executing the field_transformer. + # Mandatory vs non-mandatory attr order only matters when they are part of + # the __init__ signature and when they aren't kw_only (which are moved to + # the end and can be mandatory or non-mandatory in any order, as they will + # be specified as keyword args anyway). Check the order of those attrs: + had_default = False + for a in (a for a in attrs if a.init is not False and a.kw_only is False): + if had_default is True and a.default is NOTHING: + msg = f"No mandatory attributes allowed after an attribute with a default value or factory. Attribute in question: {a!r}" + raise ValueError(msg) + + if had_default is False and a.default is not NOTHING: + had_default = True + + # Resolve default field alias after executing field_transformer. + # This allows field_transformer to differentiate between explicit vs + # default aliases and supply their own defaults. + for a in attrs: + if not a.alias: + # Evolve is very slow, so we hold our nose and do it dirty. + _OBJ_SETATTR.__get__(a)("alias", _default_init_alias_for(a.name)) + + # Create AttrsClass *after* applying the field_transformer since it may + # add or remove attributes! + attr_names = [a.name for a in attrs] + AttrsClass = _make_attr_tuple_class(cls.__name__, attr_names) + + return _Attributes(AttrsClass(attrs), base_attrs, base_attr_map) + + +def _make_cached_property_getattr(cached_properties, original_getattr, cls): + lines = [ + # Wrapped to get `__class__` into closure cell for super() + # (It will be replaced with the newly constructed class after construction). + "def wrapper(_cls):", + " __class__ = _cls", + " def __getattr__(self, item, cached_properties=cached_properties, original_getattr=original_getattr, _cached_setattr_get=_cached_setattr_get):", + " func = cached_properties.get(item)", + " if func is not None:", + " result = func(self)", + " _setter = _cached_setattr_get(self)", + " _setter(item, result)", + " return result", + ] + if original_getattr is not None: + lines.append( + " return original_getattr(self, item)", + ) + else: + lines.extend( + [ + " try:", + " return super().__getattribute__(item)", + " except AttributeError:", + " if not hasattr(super(), '__getattr__'):", + " raise", + " return super().__getattr__(item)", + " original_error = f\"'{self.__class__.__name__}' object has no attribute '{item}'\"", + " raise AttributeError(original_error)", + ] + ) + + lines.extend( + [ + " return __getattr__", + "__getattr__ = wrapper(_cls)", + ] + ) + + unique_filename = _generate_unique_filename(cls, "getattr") + + glob = { + "cached_properties": cached_properties, + "_cached_setattr_get": _OBJ_SETATTR.__get__, + "original_getattr": original_getattr, + } + + return _linecache_and_compile( + "\n".join(lines), unique_filename, glob, locals={"_cls": cls} + )["__getattr__"] + + +def _frozen_setattrs(self, name, value): + """ + Attached to frozen classes as __setattr__. + """ + if isinstance(self, BaseException) and name in ( + "__cause__", + "__context__", + "__traceback__", + "__suppress_context__", + "__notes__", + ): + BaseException.__setattr__(self, name, value) + return + + raise FrozenInstanceError + + +def _frozen_delattrs(self, name): + """ + Attached to frozen classes as __delattr__. + """ + if isinstance(self, BaseException) and name in ("__notes__",): + BaseException.__delattr__(self, name) + return + + raise FrozenInstanceError + + +def evolve(*args, **changes): + """ + Create a new instance, based on the first positional argument with + *changes* applied. + + .. tip:: + + On Python 3.13 and later, you can also use `copy.replace` instead. + + Args: + + inst: + Instance of a class with *attrs* attributes. *inst* must be passed + as a positional argument. + + changes: + Keyword changes in the new copy. + + Returns: + A copy of inst with *changes* incorporated. + + Raises: + TypeError: + If *attr_name* couldn't be found in the class ``__init__``. + + attrs.exceptions.NotAnAttrsClassError: + If *cls* is not an *attrs* class. + + .. versionadded:: 17.1.0 + .. deprecated:: 23.1.0 + It is now deprecated to pass the instance using the keyword argument + *inst*. It will raise a warning until at least April 2024, after which + it will become an error. Always pass the instance as a positional + argument. + .. versionchanged:: 24.1.0 + *inst* can't be passed as a keyword argument anymore. + """ + try: + (inst,) = args + except ValueError: + msg = ( + f"evolve() takes 1 positional argument, but {len(args)} were given" + ) + raise TypeError(msg) from None + + cls = inst.__class__ + attrs = fields(cls) + for a in attrs: + if not a.init: + continue + attr_name = a.name # To deal with private attributes. + init_name = a.alias + if init_name not in changes: + changes[init_name] = getattr(inst, attr_name) + + return cls(**changes) + + +class _ClassBuilder: + """ + Iteratively build *one* class. + """ + + __slots__ = ( + "_add_method_dunders", + "_attr_names", + "_attrs", + "_base_attr_map", + "_base_names", + "_cache_hash", + "_cls", + "_cls_dict", + "_delete_attribs", + "_frozen", + "_has_custom_setattr", + "_has_post_init", + "_has_pre_init", + "_is_exc", + "_on_setattr", + "_pre_init_has_args", + "_repr_added", + "_script_snippets", + "_slots", + "_weakref_slot", + "_wrote_own_setattr", + ) + + def __init__( + self, + cls: type, + these, + slots, + frozen, + weakref_slot, + getstate_setstate, + auto_attribs, + kw_only, + cache_hash, + is_exc, + collect_by_mro, + on_setattr, + has_custom_setattr, + field_transformer, + ): + attrs, base_attrs, base_map = _transform_attrs( + cls, + these, + auto_attribs, + kw_only, + collect_by_mro, + field_transformer, + ) + + self._cls = cls + self._cls_dict = dict(cls.__dict__) if slots else {} + self._attrs = attrs + self._base_names = {a.name for a in base_attrs} + self._base_attr_map = base_map + self._attr_names = tuple(a.name for a in attrs) + self._slots = slots + self._frozen = frozen + self._weakref_slot = weakref_slot + self._cache_hash = cache_hash + self._has_pre_init = bool(getattr(cls, "__attrs_pre_init__", False)) + self._pre_init_has_args = False + if self._has_pre_init: + # Check if the pre init method has more arguments than just `self` + # We want to pass arguments if pre init expects arguments + pre_init_func = cls.__attrs_pre_init__ + pre_init_signature = inspect.signature(pre_init_func) + self._pre_init_has_args = len(pre_init_signature.parameters) > 1 + self._has_post_init = bool(getattr(cls, "__attrs_post_init__", False)) + self._delete_attribs = not bool(these) + self._is_exc = is_exc + self._on_setattr = on_setattr + + self._has_custom_setattr = has_custom_setattr + self._wrote_own_setattr = False + + self._cls_dict["__attrs_attrs__"] = self._attrs + + if frozen: + self._cls_dict["__setattr__"] = _frozen_setattrs + self._cls_dict["__delattr__"] = _frozen_delattrs + + self._wrote_own_setattr = True + elif on_setattr in ( + _DEFAULT_ON_SETATTR, + setters.validate, + setters.convert, + ): + has_validator = has_converter = False + for a in attrs: + if a.validator is not None: + has_validator = True + if a.converter is not None: + has_converter = True + + if has_validator and has_converter: + break + if ( + ( + on_setattr == _DEFAULT_ON_SETATTR + and not (has_validator or has_converter) + ) + or (on_setattr == setters.validate and not has_validator) + or (on_setattr == setters.convert and not has_converter) + ): + # If class-level on_setattr is set to convert + validate, but + # there's no field to convert or validate, pretend like there's + # no on_setattr. + self._on_setattr = None + + if getstate_setstate: + ( + self._cls_dict["__getstate__"], + self._cls_dict["__setstate__"], + ) = self._make_getstate_setstate() + + # tuples of script, globs, hook + self._script_snippets: list[ + tuple[str, dict, Callable[[dict, dict], Any]] + ] = [] + self._repr_added = False + + # We want to only do this check once; in 99.9% of cases these + # exist. + if not hasattr(self._cls, "__module__") or not hasattr( + self._cls, "__qualname__" + ): + self._add_method_dunders = self._add_method_dunders_safe + else: + self._add_method_dunders = self._add_method_dunders_unsafe + + def __repr__(self): + return f"<_ClassBuilder(cls={self._cls.__name__})>" + + def _eval_snippets(self) -> None: + """ + Evaluate any registered snippets in one go. + """ + script = "\n".join([snippet[0] for snippet in self._script_snippets]) + globs = {} + for _, snippet_globs, _ in self._script_snippets: + globs.update(snippet_globs) + + locs = _linecache_and_compile( + script, + _generate_unique_filename(self._cls, "methods"), + globs, + ) + + for _, _, hook in self._script_snippets: + hook(self._cls_dict, locs) + + def build_class(self): + """ + Finalize class based on the accumulated configuration. + + Builder cannot be used after calling this method. + """ + self._eval_snippets() + if self._slots is True: + cls = self._create_slots_class() + else: + cls = self._patch_original_class() + if PY_3_10_PLUS: + cls = abc.update_abstractmethods(cls) + + # The method gets only called if it's not inherited from a base class. + # _has_own_attribute does NOT work properly for classmethods. + if ( + getattr(cls, "__attrs_init_subclass__", None) + and "__attrs_init_subclass__" not in cls.__dict__ + ): + cls.__attrs_init_subclass__() + + return cls + + def _patch_original_class(self): + """ + Apply accumulated methods and return the class. + """ + cls = self._cls + base_names = self._base_names + + # Clean class of attribute definitions (`attr.ib()`s). + if self._delete_attribs: + for name in self._attr_names: + if ( + name not in base_names + and getattr(cls, name, _SENTINEL) is not _SENTINEL + ): + # An AttributeError can happen if a base class defines a + # class variable and we want to set an attribute with the + # same name by using only a type annotation. + with contextlib.suppress(AttributeError): + delattr(cls, name) + + # Attach our dunder methods. + for name, value in self._cls_dict.items(): + setattr(cls, name, value) + + # If we've inherited an attrs __setattr__ and don't write our own, + # reset it to object's. + if not self._wrote_own_setattr and getattr( + cls, "__attrs_own_setattr__", False + ): + cls.__attrs_own_setattr__ = False + + if not self._has_custom_setattr: + cls.__setattr__ = _OBJ_SETATTR + + return cls + + def _create_slots_class(self): + """ + Build and return a new class with a `__slots__` attribute. + """ + cd = { + k: v + for k, v in self._cls_dict.items() + if k not in (*tuple(self._attr_names), "__dict__", "__weakref__") + } + + # If our class doesn't have its own implementation of __setattr__ + # (either from the user or by us), check the bases, if one of them has + # an attrs-made __setattr__, that needs to be reset. We don't walk the + # MRO because we only care about our immediate base classes. + # XXX: This can be confused by subclassing a slotted attrs class with + # XXX: a non-attrs class and subclass the resulting class with an attrs + # XXX: class. See `test_slotted_confused` for details. For now that's + # XXX: OK with us. + if not self._wrote_own_setattr: + cd["__attrs_own_setattr__"] = False + + if not self._has_custom_setattr: + for base_cls in self._cls.__bases__: + if base_cls.__dict__.get("__attrs_own_setattr__", False): + cd["__setattr__"] = _OBJ_SETATTR + break + + # Traverse the MRO to collect existing slots + # and check for an existing __weakref__. + existing_slots = {} + weakref_inherited = False + for base_cls in self._cls.__mro__[1:-1]: + if base_cls.__dict__.get("__weakref__", None) is not None: + weakref_inherited = True + existing_slots.update( + { + name: getattr(base_cls, name) + for name in getattr(base_cls, "__slots__", []) + } + ) + + base_names = set(self._base_names) + + names = self._attr_names + if ( + self._weakref_slot + and "__weakref__" not in getattr(self._cls, "__slots__", ()) + and "__weakref__" not in names + and not weakref_inherited + ): + names += ("__weakref__",) + + cached_properties = { + name: cached_prop.func + for name, cached_prop in cd.items() + if isinstance(cached_prop, cached_property) + } + + # Collect methods with a `__class__` reference that are shadowed in the new class. + # To know to update them. + additional_closure_functions_to_update = [] + if cached_properties: + class_annotations = _get_annotations(self._cls) + for name, func in cached_properties.items(): + # Add cached properties to names for slotting. + names += (name,) + # Clear out function from class to avoid clashing. + del cd[name] + additional_closure_functions_to_update.append(func) + annotation = inspect.signature(func).return_annotation + if annotation is not inspect.Parameter.empty: + class_annotations[name] = annotation + + original_getattr = cd.get("__getattr__") + if original_getattr is not None: + additional_closure_functions_to_update.append(original_getattr) + + cd["__getattr__"] = _make_cached_property_getattr( + cached_properties, original_getattr, self._cls + ) + + # We only add the names of attributes that aren't inherited. + # Setting __slots__ to inherited attributes wastes memory. + slot_names = [name for name in names if name not in base_names] + + # There are slots for attributes from current class + # that are defined in parent classes. + # As their descriptors may be overridden by a child class, + # we collect them here and update the class dict + reused_slots = { + slot: slot_descriptor + for slot, slot_descriptor in existing_slots.items() + if slot in slot_names + } + slot_names = [name for name in slot_names if name not in reused_slots] + cd.update(reused_slots) + if self._cache_hash: + slot_names.append(_HASH_CACHE_FIELD) + + cd["__slots__"] = tuple(slot_names) + + cd["__qualname__"] = self._cls.__qualname__ + + # Create new class based on old class and our methods. + cls = type(self._cls)(self._cls.__name__, self._cls.__bases__, cd) + + # The following is a fix for + # <https://github.com/python-attrs/attrs/issues/102>. + # If a method mentions `__class__` or uses the no-arg super(), the + # compiler will bake a reference to the class in the method itself + # as `method.__closure__`. Since we replace the class with a + # clone, we rewrite these references so it keeps working. + for item in itertools.chain( + cls.__dict__.values(), additional_closure_functions_to_update + ): + if isinstance(item, (classmethod, staticmethod)): + # Class- and staticmethods hide their functions inside. + # These might need to be rewritten as well. + closure_cells = getattr(item.__func__, "__closure__", None) + elif isinstance(item, property): + # Workaround for property `super()` shortcut (PY3-only). + # There is no universal way for other descriptors. + closure_cells = getattr(item.fget, "__closure__", None) + else: + closure_cells = getattr(item, "__closure__", None) + + if not closure_cells: # Catch None or the empty list. + continue + for cell in closure_cells: + try: + match = cell.cell_contents is self._cls + except ValueError: # noqa: PERF203 + # ValueError: Cell is empty + pass + else: + if match: + cell.cell_contents = cls + return cls + + def add_repr(self, ns): + script, globs = _make_repr_script(self._attrs, ns) + + def _attach_repr(cls_dict, globs): + cls_dict["__repr__"] = self._add_method_dunders(globs["__repr__"]) + + self._script_snippets.append((script, globs, _attach_repr)) + self._repr_added = True + return self + + def add_str(self): + if not self._repr_added: + msg = "__str__ can only be generated if a __repr__ exists." + raise ValueError(msg) + + def __str__(self): + return self.__repr__() + + self._cls_dict["__str__"] = self._add_method_dunders(__str__) + return self + + def _make_getstate_setstate(self): + """ + Create custom __setstate__ and __getstate__ methods. + """ + # __weakref__ is not writable. + state_attr_names = tuple( + an for an in self._attr_names if an != "__weakref__" + ) + + def slots_getstate(self): + """ + Automatically created by attrs. + """ + return {name: getattr(self, name) for name in state_attr_names} + + hash_caching_enabled = self._cache_hash + + def slots_setstate(self, state): + """ + Automatically created by attrs. + """ + __bound_setattr = _OBJ_SETATTR.__get__(self) + if isinstance(state, tuple): + # Backward compatibility with attrs instances pickled with + # attrs versions before v22.2.0 which stored tuples. + for name, value in zip(state_attr_names, state): + __bound_setattr(name, value) + else: + for name in state_attr_names: + if name in state: + __bound_setattr(name, state[name]) + + # The hash code cache is not included when the object is + # serialized, but it still needs to be initialized to None to + # indicate that the first call to __hash__ should be a cache + # miss. + if hash_caching_enabled: + __bound_setattr(_HASH_CACHE_FIELD, None) + + return slots_getstate, slots_setstate + + def make_unhashable(self): + self._cls_dict["__hash__"] = None + return self + + def add_hash(self): + script, globs = _make_hash_script( + self._cls, + self._attrs, + frozen=self._frozen, + cache_hash=self._cache_hash, + ) + + def attach_hash(cls_dict: dict, locs: dict) -> None: + cls_dict["__hash__"] = self._add_method_dunders(locs["__hash__"]) + + self._script_snippets.append((script, globs, attach_hash)) + + return self + + def add_init(self): + script, globs, annotations = _make_init_script( + self._cls, + self._attrs, + self._has_pre_init, + self._pre_init_has_args, + self._has_post_init, + self._frozen, + self._slots, + self._cache_hash, + self._base_attr_map, + self._is_exc, + self._on_setattr, + attrs_init=False, + ) + + def _attach_init(cls_dict, globs): + init = globs["__init__"] + init.__annotations__ = annotations + cls_dict["__init__"] = self._add_method_dunders(init) + + self._script_snippets.append((script, globs, _attach_init)) + + return self + + def add_replace(self): + self._cls_dict["__replace__"] = self._add_method_dunders( + lambda self, **changes: evolve(self, **changes) + ) + return self + + def add_match_args(self): + self._cls_dict["__match_args__"] = tuple( + field.name + for field in self._attrs + if field.init and not field.kw_only + ) + + def add_attrs_init(self): + script, globs, annotations = _make_init_script( + self._cls, + self._attrs, + self._has_pre_init, + self._pre_init_has_args, + self._has_post_init, + self._frozen, + self._slots, + self._cache_hash, + self._base_attr_map, + self._is_exc, + self._on_setattr, + attrs_init=True, + ) + + def _attach_attrs_init(cls_dict, globs): + init = globs["__attrs_init__"] + init.__annotations__ = annotations + cls_dict["__attrs_init__"] = self._add_method_dunders(init) + + self._script_snippets.append((script, globs, _attach_attrs_init)) + + return self + + def add_eq(self): + cd = self._cls_dict + + script, globs = _make_eq_script(self._attrs) + + def _attach_eq(cls_dict, globs): + cls_dict["__eq__"] = self._add_method_dunders(globs["__eq__"]) + + self._script_snippets.append((script, globs, _attach_eq)) + + cd["__ne__"] = __ne__ + + return self + + def add_order(self): + cd = self._cls_dict + + cd["__lt__"], cd["__le__"], cd["__gt__"], cd["__ge__"] = ( + self._add_method_dunders(meth) + for meth in _make_order(self._cls, self._attrs) + ) + + return self + + def add_setattr(self): + sa_attrs = {} + for a in self._attrs: + on_setattr = a.on_setattr or self._on_setattr + if on_setattr and on_setattr is not setters.NO_OP: + sa_attrs[a.name] = a, on_setattr + + if not sa_attrs: + return self + + if self._has_custom_setattr: + # We need to write a __setattr__ but there already is one! + msg = "Can't combine custom __setattr__ with on_setattr hooks." + raise ValueError(msg) + + # docstring comes from _add_method_dunders + def __setattr__(self, name, val): + try: + a, hook = sa_attrs[name] + except KeyError: + nval = val + else: + nval = hook(self, a, val) + + _OBJ_SETATTR(self, name, nval) + + self._cls_dict["__attrs_own_setattr__"] = True + self._cls_dict["__setattr__"] = self._add_method_dunders(__setattr__) + self._wrote_own_setattr = True + + return self + + def _add_method_dunders_unsafe(self, method: Callable) -> Callable: + """ + Add __module__ and __qualname__ to a *method*. + """ + method.__module__ = self._cls.__module__ + + method.__qualname__ = f"{self._cls.__qualname__}.{method.__name__}" + + method.__doc__ = ( + f"Method generated by attrs for class {self._cls.__qualname__}." + ) + + return method + + def _add_method_dunders_safe(self, method: Callable) -> Callable: + """ + Add __module__ and __qualname__ to a *method* if possible. + """ + with contextlib.suppress(AttributeError): + method.__module__ = self._cls.__module__ + + with contextlib.suppress(AttributeError): + method.__qualname__ = f"{self._cls.__qualname__}.{method.__name__}" + + with contextlib.suppress(AttributeError): + method.__doc__ = f"Method generated by attrs for class {self._cls.__qualname__}." + + return method + + +def _determine_attrs_eq_order(cmp, eq, order, default_eq): + """ + Validate the combination of *cmp*, *eq*, and *order*. Derive the effective + values of eq and order. If *eq* is None, set it to *default_eq*. + """ + if cmp is not None and any((eq is not None, order is not None)): + msg = "Don't mix `cmp` with `eq' and `order`." + raise ValueError(msg) + + # cmp takes precedence due to bw-compatibility. + if cmp is not None: + return cmp, cmp + + # If left None, equality is set to the specified default and ordering + # mirrors equality. + if eq is None: + eq = default_eq + + if order is None: + order = eq + + if eq is False and order is True: + msg = "`order` can only be True if `eq` is True too." + raise ValueError(msg) + + return eq, order + + +def _determine_attrib_eq_order(cmp, eq, order, default_eq): + """ + Validate the combination of *cmp*, *eq*, and *order*. Derive the effective + values of eq and order. If *eq* is None, set it to *default_eq*. + """ + if cmp is not None and any((eq is not None, order is not None)): + msg = "Don't mix `cmp` with `eq' and `order`." + raise ValueError(msg) + + def decide_callable_or_boolean(value): + """ + Decide whether a key function is used. + """ + if callable(value): + value, key = True, value + else: + key = None + return value, key + + # cmp takes precedence due to bw-compatibility. + if cmp is not None: + cmp, cmp_key = decide_callable_or_boolean(cmp) + return cmp, cmp_key, cmp, cmp_key + + # If left None, equality is set to the specified default and ordering + # mirrors equality. + if eq is None: + eq, eq_key = default_eq, None + else: + eq, eq_key = decide_callable_or_boolean(eq) + + if order is None: + order, order_key = eq, eq_key + else: + order, order_key = decide_callable_or_boolean(order) + + if eq is False and order is True: + msg = "`order` can only be True if `eq` is True too." + raise ValueError(msg) + + return eq, eq_key, order, order_key + + +def _determine_whether_to_implement( + cls, flag, auto_detect, dunders, default=True +): + """ + Check whether we should implement a set of methods for *cls*. + + *flag* is the argument passed into @attr.s like 'init', *auto_detect* the + same as passed into @attr.s and *dunders* is a tuple of attribute names + whose presence signal that the user has implemented it themselves. + + Return *default* if no reason for either for or against is found. + """ + if flag is True or flag is False: + return flag + + if flag is None and auto_detect is False: + return default + + # Logically, flag is None and auto_detect is True here. + for dunder in dunders: + if _has_own_attribute(cls, dunder): + return False + + return default + + +def attrs( + maybe_cls=None, + these=None, + repr_ns=None, + repr=None, + cmp=None, + hash=None, + init=None, + slots=False, + frozen=False, + weakref_slot=True, + str=False, + auto_attribs=False, + kw_only=False, + cache_hash=False, + auto_exc=False, + eq=None, + order=None, + auto_detect=False, + collect_by_mro=False, + getstate_setstate=None, + on_setattr=None, + field_transformer=None, + match_args=True, + unsafe_hash=None, +): + r""" + A class decorator that adds :term:`dunder methods` according to the + specified attributes using `attr.ib` or the *these* argument. + + Consider using `attrs.define` / `attrs.frozen` in new code (``attr.s`` will + *never* go away, though). + + Args: + repr_ns (str): + When using nested classes, there was no way in Python 2 to + automatically detect that. This argument allows to set a custom + name for a more meaningful ``repr`` output. This argument is + pointless in Python 3 and is therefore deprecated. + + .. caution:: + Refer to `attrs.define` for the rest of the parameters, but note that they + can have different defaults. + + Notably, leaving *on_setattr* as `None` will **not** add any hooks. + + .. versionadded:: 16.0.0 *slots* + .. versionadded:: 16.1.0 *frozen* + .. versionadded:: 16.3.0 *str* + .. versionadded:: 16.3.0 Support for ``__attrs_post_init__``. + .. versionchanged:: 17.1.0 + *hash* supports `None` as value which is also the default now. + .. versionadded:: 17.3.0 *auto_attribs* + .. versionchanged:: 18.1.0 + If *these* is passed, no attributes are deleted from the class body. + .. versionchanged:: 18.1.0 If *these* is ordered, the order is retained. + .. versionadded:: 18.2.0 *weakref_slot* + .. deprecated:: 18.2.0 + ``__lt__``, ``__le__``, ``__gt__``, and ``__ge__`` now raise a + `DeprecationWarning` if the classes compared are subclasses of + each other. ``__eq`` and ``__ne__`` never tried to compared subclasses + to each other. + .. versionchanged:: 19.2.0 + ``__lt__``, ``__le__``, ``__gt__``, and ``__ge__`` now do not consider + subclasses comparable anymore. + .. versionadded:: 18.2.0 *kw_only* + .. versionadded:: 18.2.0 *cache_hash* + .. versionadded:: 19.1.0 *auto_exc* + .. deprecated:: 19.2.0 *cmp* Removal on or after 2021-06-01. + .. versionadded:: 19.2.0 *eq* and *order* + .. versionadded:: 20.1.0 *auto_detect* + .. versionadded:: 20.1.0 *collect_by_mro* + .. versionadded:: 20.1.0 *getstate_setstate* + .. versionadded:: 20.1.0 *on_setattr* + .. versionadded:: 20.3.0 *field_transformer* + .. versionchanged:: 21.1.0 + ``init=False`` injects ``__attrs_init__`` + .. versionchanged:: 21.1.0 Support for ``__attrs_pre_init__`` + .. versionchanged:: 21.1.0 *cmp* undeprecated + .. versionadded:: 21.3.0 *match_args* + .. versionadded:: 22.2.0 + *unsafe_hash* as an alias for *hash* (for :pep:`681` compliance). + .. deprecated:: 24.1.0 *repr_ns* + .. versionchanged:: 24.1.0 + Instances are not compared as tuples of attributes anymore, but using a + big ``and`` condition. This is faster and has more correct behavior for + uncomparable values like `math.nan`. + .. versionadded:: 24.1.0 + If a class has an *inherited* classmethod called + ``__attrs_init_subclass__``, it is executed after the class is created. + .. deprecated:: 24.1.0 *hash* is deprecated in favor of *unsafe_hash*. + """ + if repr_ns is not None: + import warnings + + warnings.warn( + DeprecationWarning( + "The `repr_ns` argument is deprecated and will be removed in or after August 2025." + ), + stacklevel=2, + ) + + eq_, order_ = _determine_attrs_eq_order(cmp, eq, order, None) + + # unsafe_hash takes precedence due to PEP 681. + if unsafe_hash is not None: + hash = unsafe_hash + + if isinstance(on_setattr, (list, tuple)): + on_setattr = setters.pipe(*on_setattr) + + def wrap(cls): + is_frozen = frozen or _has_frozen_base_class(cls) + is_exc = auto_exc is True and issubclass(cls, BaseException) + has_own_setattr = auto_detect and _has_own_attribute( + cls, "__setattr__" + ) + + if has_own_setattr and is_frozen: + msg = "Can't freeze a class with a custom __setattr__." + raise ValueError(msg) + + builder = _ClassBuilder( + cls, + these, + slots, + is_frozen, + weakref_slot, + _determine_whether_to_implement( + cls, + getstate_setstate, + auto_detect, + ("__getstate__", "__setstate__"), + default=slots, + ), + auto_attribs, + kw_only, + cache_hash, + is_exc, + collect_by_mro, + on_setattr, + has_own_setattr, + field_transformer, + ) + + if _determine_whether_to_implement( + cls, repr, auto_detect, ("__repr__",) + ): + builder.add_repr(repr_ns) + + if str is True: + builder.add_str() + + eq = _determine_whether_to_implement( + cls, eq_, auto_detect, ("__eq__", "__ne__") + ) + if not is_exc and eq is True: + builder.add_eq() + if not is_exc and _determine_whether_to_implement( + cls, order_, auto_detect, ("__lt__", "__le__", "__gt__", "__ge__") + ): + builder.add_order() + + if not frozen: + builder.add_setattr() + + nonlocal hash + if ( + hash is None + and auto_detect is True + and _has_own_attribute(cls, "__hash__") + ): + hash = False + + if hash is not True and hash is not False and hash is not None: + # Can't use `hash in` because 1 == True for example. + msg = "Invalid value for hash. Must be True, False, or None." + raise TypeError(msg) + + if hash is False or (hash is None and eq is False) or is_exc: + # Don't do anything. Should fall back to __object__'s __hash__ + # which is by id. + if cache_hash: + msg = "Invalid value for cache_hash. To use hash caching, hashing must be either explicitly or implicitly enabled." + raise TypeError(msg) + elif hash is True or ( + hash is None and eq is True and is_frozen is True + ): + # Build a __hash__ if told so, or if it's safe. + builder.add_hash() + else: + # Raise TypeError on attempts to hash. + if cache_hash: + msg = "Invalid value for cache_hash. To use hash caching, hashing must be either explicitly or implicitly enabled." + raise TypeError(msg) + builder.make_unhashable() + + if _determine_whether_to_implement( + cls, init, auto_detect, ("__init__",) + ): + builder.add_init() + else: + builder.add_attrs_init() + if cache_hash: + msg = "Invalid value for cache_hash. To use hash caching, init must be True." + raise TypeError(msg) + + if PY_3_13_PLUS and not _has_own_attribute(cls, "__replace__"): + builder.add_replace() + + if ( + PY_3_10_PLUS + and match_args + and not _has_own_attribute(cls, "__match_args__") + ): + builder.add_match_args() + + return builder.build_class() + + # maybe_cls's type depends on the usage of the decorator. It's a class + # if it's used as `@attrs` but `None` if used as `@attrs()`. + if maybe_cls is None: + return wrap + + return wrap(maybe_cls) + + +_attrs = attrs +""" +Internal alias so we can use it in functions that take an argument called +*attrs*. +""" + + +def _has_frozen_base_class(cls): + """ + Check whether *cls* has a frozen ancestor by looking at its + __setattr__. + """ + return cls.__setattr__ is _frozen_setattrs + + +def _generate_unique_filename(cls: type, func_name: str) -> str: + """ + Create a "filename" suitable for a function being generated. + """ + return ( + f"<attrs generated {func_name} {cls.__module__}." + f"{getattr(cls, '__qualname__', cls.__name__)}>" + ) + + +def _make_hash_script( + cls: type, attrs: list[Attribute], frozen: bool, cache_hash: bool +) -> tuple[str, dict]: + attrs = tuple( + a for a in attrs if a.hash is True or (a.hash is None and a.eq is True) + ) + + tab = " " + + type_hash = hash(_generate_unique_filename(cls, "hash")) + # If eq is custom generated, we need to include the functions in globs + globs = {} + + hash_def = "def __hash__(self" + hash_func = "hash((" + closing_braces = "))" + if not cache_hash: + hash_def += "):" + else: + hash_def += ", *" + + hash_def += ", _cache_wrapper=__import__('attr._make')._make._CacheHashWrapper):" + hash_func = "_cache_wrapper(" + hash_func + closing_braces += ")" + + method_lines = [hash_def] + + def append_hash_computation_lines(prefix, indent): + """ + Generate the code for actually computing the hash code. + Below this will either be returned directly or used to compute + a value which is then cached, depending on the value of cache_hash + """ + + method_lines.extend( + [ + indent + prefix + hash_func, + indent + f" {type_hash},", + ] + ) + + for a in attrs: + if a.eq_key: + cmp_name = f"_{a.name}_key" + globs[cmp_name] = a.eq_key + method_lines.append( + indent + f" {cmp_name}(self.{a.name})," + ) + else: + method_lines.append(indent + f" self.{a.name},") + + method_lines.append(indent + " " + closing_braces) + + if cache_hash: + method_lines.append(tab + f"if self.{_HASH_CACHE_FIELD} is None:") + if frozen: + append_hash_computation_lines( + f"object.__setattr__(self, '{_HASH_CACHE_FIELD}', ", tab * 2 + ) + method_lines.append(tab * 2 + ")") # close __setattr__ + else: + append_hash_computation_lines( + f"self.{_HASH_CACHE_FIELD} = ", tab * 2 + ) + method_lines.append(tab + f"return self.{_HASH_CACHE_FIELD}") + else: + append_hash_computation_lines("return ", tab) + + script = "\n".join(method_lines) + return script, globs + + +def _add_hash(cls: type, attrs: list[Attribute]): + """ + Add a hash method to *cls*. + """ + script, globs = _make_hash_script( + cls, attrs, frozen=False, cache_hash=False + ) + _compile_and_eval( + script, globs, filename=_generate_unique_filename(cls, "__hash__") + ) + cls.__hash__ = globs["__hash__"] + return cls + + +def __ne__(self, other): + """ + Check equality and either forward a NotImplemented or + return the result negated. + """ + result = self.__eq__(other) + if result is NotImplemented: + return NotImplemented + + return not result + + +def _make_eq_script(attrs: list) -> tuple[str, dict]: + """ + Create __eq__ method for *cls* with *attrs*. + """ + attrs = [a for a in attrs if a.eq] + + lines = [ + "def __eq__(self, other):", + " if other.__class__ is not self.__class__:", + " return NotImplemented", + ] + + globs = {} + if attrs: + lines.append(" return (") + for a in attrs: + if a.eq_key: + cmp_name = f"_{a.name}_key" + # Add the key function to the global namespace + # of the evaluated function. + globs[cmp_name] = a.eq_key + lines.append( + f" {cmp_name}(self.{a.name}) == {cmp_name}(other.{a.name})" + ) + else: + lines.append(f" self.{a.name} == other.{a.name}") + if a is not attrs[-1]: + lines[-1] = f"{lines[-1]} and" + lines.append(" )") + else: + lines.append(" return True") + + script = "\n".join(lines) + + return script, globs + + +def _make_order(cls, attrs): + """ + Create ordering methods for *cls* with *attrs*. + """ + attrs = [a for a in attrs if a.order] + + def attrs_to_tuple(obj): + """ + Save us some typing. + """ + return tuple( + key(value) if key else value + for value, key in ( + (getattr(obj, a.name), a.order_key) for a in attrs + ) + ) + + def __lt__(self, other): + """ + Automatically created by attrs. + """ + if other.__class__ is self.__class__: + return attrs_to_tuple(self) < attrs_to_tuple(other) + + return NotImplemented + + def __le__(self, other): + """ + Automatically created by attrs. + """ + if other.__class__ is self.__class__: + return attrs_to_tuple(self) <= attrs_to_tuple(other) + + return NotImplemented + + def __gt__(self, other): + """ + Automatically created by attrs. + """ + if other.__class__ is self.__class__: + return attrs_to_tuple(self) > attrs_to_tuple(other) + + return NotImplemented + + def __ge__(self, other): + """ + Automatically created by attrs. + """ + if other.__class__ is self.__class__: + return attrs_to_tuple(self) >= attrs_to_tuple(other) + + return NotImplemented + + return __lt__, __le__, __gt__, __ge__ + + +def _add_eq(cls, attrs=None): + """ + Add equality methods to *cls* with *attrs*. + """ + if attrs is None: + attrs = cls.__attrs_attrs__ + + script, globs = _make_eq_script(attrs) + _compile_and_eval( + script, globs, filename=_generate_unique_filename(cls, "__eq__") + ) + cls.__eq__ = globs["__eq__"] + cls.__ne__ = __ne__ + + return cls + + +def _make_repr_script(attrs, ns) -> tuple[str, dict]: + """ + Create the source and globs for a __repr__ and return it. + """ + # Figure out which attributes to include, and which function to use to + # format them. The a.repr value can be either bool or a custom + # callable. + attr_names_with_reprs = tuple( + (a.name, (repr if a.repr is True else a.repr), a.init) + for a in attrs + if a.repr is not False + ) + globs = { + name + "_repr": r for name, r, _ in attr_names_with_reprs if r != repr + } + globs["_compat"] = _compat + globs["AttributeError"] = AttributeError + globs["NOTHING"] = NOTHING + attribute_fragments = [] + for name, r, i in attr_names_with_reprs: + accessor = ( + "self." + name if i else 'getattr(self, "' + name + '", NOTHING)' + ) + fragment = ( + "%s={%s!r}" % (name, accessor) + if r == repr + else "%s={%s_repr(%s)}" % (name, name, accessor) + ) + attribute_fragments.append(fragment) + repr_fragment = ", ".join(attribute_fragments) + + if ns is None: + cls_name_fragment = '{self.__class__.__qualname__.rsplit(">.", 1)[-1]}' + else: + cls_name_fragment = ns + ".{self.__class__.__name__}" + + lines = [ + "def __repr__(self):", + " try:", + " already_repring = _compat.repr_context.already_repring", + " except AttributeError:", + " already_repring = {id(self),}", + " _compat.repr_context.already_repring = already_repring", + " else:", + " if id(self) in already_repring:", + " return '...'", + " else:", + " already_repring.add(id(self))", + " try:", + f" return f'{cls_name_fragment}({repr_fragment})'", + " finally:", + " already_repring.remove(id(self))", + ] + + return "\n".join(lines), globs + + +def _add_repr(cls, ns=None, attrs=None): + """ + Add a repr method to *cls*. + """ + if attrs is None: + attrs = cls.__attrs_attrs__ + + script, globs = _make_repr_script(attrs, ns) + _compile_and_eval( + script, globs, filename=_generate_unique_filename(cls, "__repr__") + ) + cls.__repr__ = globs["__repr__"] + return cls + + +def fields(cls): + """ + Return the tuple of *attrs* attributes for a class. + + The tuple also allows accessing the fields by their names (see below for + examples). + + Args: + cls (type): Class to introspect. + + Raises: + TypeError: If *cls* is not a class. + + attrs.exceptions.NotAnAttrsClassError: + If *cls* is not an *attrs* class. + + Returns: + tuple (with name accessors) of `attrs.Attribute` + + .. versionchanged:: 16.2.0 Returned tuple allows accessing the fields + by name. + .. versionchanged:: 23.1.0 Add support for generic classes. + """ + generic_base = get_generic_base(cls) + + if generic_base is None and not isinstance(cls, type): + msg = "Passed object must be a class." + raise TypeError(msg) + + attrs = getattr(cls, "__attrs_attrs__", None) + + if attrs is None: + if generic_base is not None: + attrs = getattr(generic_base, "__attrs_attrs__", None) + if attrs is not None: + # Even though this is global state, stick it on here to speed + # it up. We rely on `cls` being cached for this to be + # efficient. + cls.__attrs_attrs__ = attrs + return attrs + msg = f"{cls!r} is not an attrs-decorated class." + raise NotAnAttrsClassError(msg) + + return attrs + + +def fields_dict(cls): + """ + Return an ordered dictionary of *attrs* attributes for a class, whose keys + are the attribute names. + + Args: + cls (type): Class to introspect. + + Raises: + TypeError: If *cls* is not a class. + + attrs.exceptions.NotAnAttrsClassError: + If *cls* is not an *attrs* class. + + Returns: + dict[str, attrs.Attribute]: Dict of attribute name to definition + + .. versionadded:: 18.1.0 + """ + if not isinstance(cls, type): + msg = "Passed object must be a class." + raise TypeError(msg) + attrs = getattr(cls, "__attrs_attrs__", None) + if attrs is None: + msg = f"{cls!r} is not an attrs-decorated class." + raise NotAnAttrsClassError(msg) + return {a.name: a for a in attrs} + + +def validate(inst): + """ + Validate all attributes on *inst* that have a validator. + + Leaves all exceptions through. + + Args: + inst: Instance of a class with *attrs* attributes. + """ + if _config._run_validators is False: + return + + for a in fields(inst.__class__): + v = a.validator + if v is not None: + v(inst, a, getattr(inst, a.name)) + + +def _is_slot_attr(a_name, base_attr_map): + """ + Check if the attribute name comes from a slot class. + """ + cls = base_attr_map.get(a_name) + return cls and "__slots__" in cls.__dict__ + + +def _make_init_script( + cls, + attrs, + pre_init, + pre_init_has_args, + post_init, + frozen, + slots, + cache_hash, + base_attr_map, + is_exc, + cls_on_setattr, + attrs_init, +) -> tuple[str, dict, dict]: + has_cls_on_setattr = ( + cls_on_setattr is not None and cls_on_setattr is not setters.NO_OP + ) + + if frozen and has_cls_on_setattr: + msg = "Frozen classes can't use on_setattr." + raise ValueError(msg) + + needs_cached_setattr = cache_hash or frozen + filtered_attrs = [] + attr_dict = {} + for a in attrs: + if not a.init and a.default is NOTHING: + continue + + filtered_attrs.append(a) + attr_dict[a.name] = a + + if a.on_setattr is not None: + if frozen is True: + msg = "Frozen classes can't use on_setattr." + raise ValueError(msg) + + needs_cached_setattr = True + elif has_cls_on_setattr and a.on_setattr is not setters.NO_OP: + needs_cached_setattr = True + + script, globs, annotations = _attrs_to_init_script( + filtered_attrs, + frozen, + slots, + pre_init, + pre_init_has_args, + post_init, + cache_hash, + base_attr_map, + is_exc, + needs_cached_setattr, + has_cls_on_setattr, + "__attrs_init__" if attrs_init else "__init__", + ) + if cls.__module__ in sys.modules: + # This makes typing.get_type_hints(CLS.__init__) resolve string types. + globs.update(sys.modules[cls.__module__].__dict__) + + globs.update({"NOTHING": NOTHING, "attr_dict": attr_dict}) + + if needs_cached_setattr: + # Save the lookup overhead in __init__ if we need to circumvent + # setattr hooks. + globs["_cached_setattr_get"] = _OBJ_SETATTR.__get__ + + return script, globs, annotations + + +def _setattr(attr_name: str, value_var: str, has_on_setattr: bool) -> str: + """ + Use the cached object.setattr to set *attr_name* to *value_var*. + """ + return f"_setattr('{attr_name}', {value_var})" + + +def _setattr_with_converter( + attr_name: str, value_var: str, has_on_setattr: bool, converter: Converter +) -> str: + """ + Use the cached object.setattr to set *attr_name* to *value_var*, but run + its converter first. + """ + return f"_setattr('{attr_name}', {converter._fmt_converter_call(attr_name, value_var)})" + + +def _assign(attr_name: str, value: str, has_on_setattr: bool) -> str: + """ + Unless *attr_name* has an on_setattr hook, use normal assignment. Otherwise + relegate to _setattr. + """ + if has_on_setattr: + return _setattr(attr_name, value, True) + + return f"self.{attr_name} = {value}" + + +def _assign_with_converter( + attr_name: str, value_var: str, has_on_setattr: bool, converter: Converter +) -> str: + """ + Unless *attr_name* has an on_setattr hook, use normal assignment after + conversion. Otherwise relegate to _setattr_with_converter. + """ + if has_on_setattr: + return _setattr_with_converter(attr_name, value_var, True, converter) + + return f"self.{attr_name} = {converter._fmt_converter_call(attr_name, value_var)}" + + +def _determine_setters( + frozen: bool, slots: bool, base_attr_map: dict[str, type] +): + """ + Determine the correct setter functions based on whether a class is frozen + and/or slotted. + """ + if frozen is True: + if slots is True: + return (), _setattr, _setattr_with_converter + + # Dict frozen classes assign directly to __dict__. + # But only if the attribute doesn't come from an ancestor slot + # class. + # Note _inst_dict will be used again below if cache_hash is True + + def fmt_setter( + attr_name: str, value_var: str, has_on_setattr: bool + ) -> str: + if _is_slot_attr(attr_name, base_attr_map): + return _setattr(attr_name, value_var, has_on_setattr) + + return f"_inst_dict['{attr_name}'] = {value_var}" + + def fmt_setter_with_converter( + attr_name: str, + value_var: str, + has_on_setattr: bool, + converter: Converter, + ) -> str: + if has_on_setattr or _is_slot_attr(attr_name, base_attr_map): + return _setattr_with_converter( + attr_name, value_var, has_on_setattr, converter + ) + + return f"_inst_dict['{attr_name}'] = {converter._fmt_converter_call(attr_name, value_var)}" + + return ( + ("_inst_dict = self.__dict__",), + fmt_setter, + fmt_setter_with_converter, + ) + + # Not frozen -- we can just assign directly. + return (), _assign, _assign_with_converter + + +def _attrs_to_init_script( + attrs: list[Attribute], + is_frozen: bool, + is_slotted: bool, + call_pre_init: bool, + pre_init_has_args: bool, + call_post_init: bool, + does_cache_hash: bool, + base_attr_map: dict[str, type], + is_exc: bool, + needs_cached_setattr: bool, + has_cls_on_setattr: bool, + method_name: str, +) -> tuple[str, dict, dict]: + """ + Return a script of an initializer for *attrs*, a dict of globals, and + annotations for the initializer. + + The globals are required by the generated script. + """ + lines = ["self.__attrs_pre_init__()"] if call_pre_init else [] + + if needs_cached_setattr: + lines.append( + # Circumvent the __setattr__ descriptor to save one lookup per + # assignment. Note _setattr will be used again below if + # does_cache_hash is True. + "_setattr = _cached_setattr_get(self)" + ) + + extra_lines, fmt_setter, fmt_setter_with_converter = _determine_setters( + is_frozen, is_slotted, base_attr_map + ) + lines.extend(extra_lines) + + args = [] + kw_only_args = [] + attrs_to_validate = [] + + # This is a dictionary of names to validator and converter callables. + # Injecting this into __init__ globals lets us avoid lookups. + names_for_globals = {} + annotations = {"return": None} + + for a in attrs: + if a.validator: + attrs_to_validate.append(a) + + attr_name = a.name + has_on_setattr = a.on_setattr is not None or ( + a.on_setattr is not setters.NO_OP and has_cls_on_setattr + ) + # a.alias is set to maybe-mangled attr_name in _ClassBuilder if not + # explicitly provided + arg_name = a.alias + + has_factory = isinstance(a.default, Factory) + maybe_self = "self" if has_factory and a.default.takes_self else "" + + if a.converter is not None and not isinstance(a.converter, Converter): + converter = Converter(a.converter) + else: + converter = a.converter + + if a.init is False: + if has_factory: + init_factory_name = _INIT_FACTORY_PAT % (a.name,) + if converter is not None: + lines.append( + fmt_setter_with_converter( + attr_name, + init_factory_name + f"({maybe_self})", + has_on_setattr, + converter, + ) + ) + names_for_globals[converter._get_global_name(a.name)] = ( + converter.converter + ) + else: + lines.append( + fmt_setter( + attr_name, + init_factory_name + f"({maybe_self})", + has_on_setattr, + ) + ) + names_for_globals[init_factory_name] = a.default.factory + elif converter is not None: + lines.append( + fmt_setter_with_converter( + attr_name, + f"attr_dict['{attr_name}'].default", + has_on_setattr, + converter, + ) + ) + names_for_globals[converter._get_global_name(a.name)] = ( + converter.converter + ) + else: + lines.append( + fmt_setter( + attr_name, + f"attr_dict['{attr_name}'].default", + has_on_setattr, + ) + ) + elif a.default is not NOTHING and not has_factory: + arg = f"{arg_name}=attr_dict['{attr_name}'].default" + if a.kw_only: + kw_only_args.append(arg) + else: + args.append(arg) + + if converter is not None: + lines.append( + fmt_setter_with_converter( + attr_name, arg_name, has_on_setattr, converter + ) + ) + names_for_globals[converter._get_global_name(a.name)] = ( + converter.converter + ) + else: + lines.append(fmt_setter(attr_name, arg_name, has_on_setattr)) + + elif has_factory: + arg = f"{arg_name}=NOTHING" + if a.kw_only: + kw_only_args.append(arg) + else: + args.append(arg) + lines.append(f"if {arg_name} is not NOTHING:") + + init_factory_name = _INIT_FACTORY_PAT % (a.name,) + if converter is not None: + lines.append( + " " + + fmt_setter_with_converter( + attr_name, arg_name, has_on_setattr, converter + ) + ) + lines.append("else:") + lines.append( + " " + + fmt_setter_with_converter( + attr_name, + init_factory_name + "(" + maybe_self + ")", + has_on_setattr, + converter, + ) + ) + names_for_globals[converter._get_global_name(a.name)] = ( + converter.converter + ) + else: + lines.append( + " " + fmt_setter(attr_name, arg_name, has_on_setattr) + ) + lines.append("else:") + lines.append( + " " + + fmt_setter( + attr_name, + init_factory_name + "(" + maybe_self + ")", + has_on_setattr, + ) + ) + names_for_globals[init_factory_name] = a.default.factory + else: + if a.kw_only: + kw_only_args.append(arg_name) + else: + args.append(arg_name) + + if converter is not None: + lines.append( + fmt_setter_with_converter( + attr_name, arg_name, has_on_setattr, converter + ) + ) + names_for_globals[converter._get_global_name(a.name)] = ( + converter.converter + ) + else: + lines.append(fmt_setter(attr_name, arg_name, has_on_setattr)) + + if a.init is True: + if a.type is not None and converter is None: + annotations[arg_name] = a.type + elif converter is not None and converter._first_param_type: + # Use the type from the converter if present. + annotations[arg_name] = converter._first_param_type + + if attrs_to_validate: # we can skip this if there are no validators. + names_for_globals["_config"] = _config + lines.append("if _config._run_validators is True:") + for a in attrs_to_validate: + val_name = "__attr_validator_" + a.name + attr_name = "__attr_" + a.name + lines.append(f" {val_name}(self, {attr_name}, self.{a.name})") + names_for_globals[val_name] = a.validator + names_for_globals[attr_name] = a + + if call_post_init: + lines.append("self.__attrs_post_init__()") + + # Because this is set only after __attrs_post_init__ is called, a crash + # will result if post-init tries to access the hash code. This seemed + # preferable to setting this beforehand, in which case alteration to field + # values during post-init combined with post-init accessing the hash code + # would result in silent bugs. + if does_cache_hash: + if is_frozen: + if is_slotted: + init_hash_cache = f"_setattr('{_HASH_CACHE_FIELD}', None)" + else: + init_hash_cache = f"_inst_dict['{_HASH_CACHE_FIELD}'] = None" + else: + init_hash_cache = f"self.{_HASH_CACHE_FIELD} = None" + lines.append(init_hash_cache) + + # For exceptions we rely on BaseException.__init__ for proper + # initialization. + if is_exc: + vals = ",".join(f"self.{a.name}" for a in attrs if a.init) + + lines.append(f"BaseException.__init__(self, {vals})") + + args = ", ".join(args) + pre_init_args = args + if kw_only_args: + # leading comma & kw_only args + args += f"{', ' if args else ''}*, {', '.join(kw_only_args)}" + pre_init_kw_only_args = ", ".join( + [ + f"{kw_arg_name}={kw_arg_name}" + # We need to remove the defaults from the kw_only_args. + for kw_arg_name in (kwa.split("=")[0] for kwa in kw_only_args) + ] + ) + pre_init_args += ", " if pre_init_args else "" + pre_init_args += pre_init_kw_only_args + + if call_pre_init and pre_init_has_args: + # If pre init method has arguments, pass same arguments as `__init__`. + lines[0] = f"self.__attrs_pre_init__({pre_init_args})" + + # Python <3.12 doesn't allow backslashes in f-strings. + NL = "\n " + return ( + f"""def {method_name}(self, {args}): + {NL.join(lines) if lines else "pass"} +""", + names_for_globals, + annotations, + ) + + +def _default_init_alias_for(name: str) -> str: + """ + The default __init__ parameter name for a field. + + This performs private-name adjustment via leading-unscore stripping, + and is the default value of Attribute.alias if not provided. + """ + + return name.lstrip("_") + + +class Attribute: + """ + *Read-only* representation of an attribute. + + .. warning:: + + You should never instantiate this class yourself. + + The class has *all* arguments of `attr.ib` (except for ``factory`` which is + only syntactic sugar for ``default=Factory(...)`` plus the following: + + - ``name`` (`str`): The name of the attribute. + - ``alias`` (`str`): The __init__ parameter name of the attribute, after + any explicit overrides and default private-attribute-name handling. + - ``inherited`` (`bool`): Whether or not that attribute has been inherited + from a base class. + - ``eq_key`` and ``order_key`` (`typing.Callable` or `None`): The + callables that are used for comparing and ordering objects by this + attribute, respectively. These are set by passing a callable to + `attr.ib`'s ``eq``, ``order``, or ``cmp`` arguments. See also + :ref:`comparison customization <custom-comparison>`. + + Instances of this class are frequently used for introspection purposes + like: + + - `fields` returns a tuple of them. + - Validators get them passed as the first argument. + - The :ref:`field transformer <transform-fields>` hook receives a list of + them. + - The ``alias`` property exposes the __init__ parameter name of the field, + with any overrides and default private-attribute handling applied. + + + .. versionadded:: 20.1.0 *inherited* + .. versionadded:: 20.1.0 *on_setattr* + .. versionchanged:: 20.2.0 *inherited* is not taken into account for + equality checks and hashing anymore. + .. versionadded:: 21.1.0 *eq_key* and *order_key* + .. versionadded:: 22.2.0 *alias* + + For the full version history of the fields, see `attr.ib`. + """ + + # These slots must NOT be reordered because we use them later for + # instantiation. + __slots__ = ( # noqa: RUF023 + "name", + "default", + "validator", + "repr", + "eq", + "eq_key", + "order", + "order_key", + "hash", + "init", + "metadata", + "type", + "converter", + "kw_only", + "inherited", + "on_setattr", + "alias", + ) + + def __init__( + self, + name, + default, + validator, + repr, + cmp, # XXX: unused, remove along with other cmp code. + hash, + init, + inherited, + metadata=None, + type=None, + converter=None, + kw_only=False, + eq=None, + eq_key=None, + order=None, + order_key=None, + on_setattr=None, + alias=None, + ): + eq, eq_key, order, order_key = _determine_attrib_eq_order( + cmp, eq_key or eq, order_key or order, True + ) + + # Cache this descriptor here to speed things up later. + bound_setattr = _OBJ_SETATTR.__get__(self) + + # Despite the big red warning, people *do* instantiate `Attribute` + # themselves. + bound_setattr("name", name) + bound_setattr("default", default) + bound_setattr("validator", validator) + bound_setattr("repr", repr) + bound_setattr("eq", eq) + bound_setattr("eq_key", eq_key) + bound_setattr("order", order) + bound_setattr("order_key", order_key) + bound_setattr("hash", hash) + bound_setattr("init", init) + bound_setattr("converter", converter) + bound_setattr( + "metadata", + ( + types.MappingProxyType(dict(metadata)) # Shallow copy + if metadata + else _EMPTY_METADATA_SINGLETON + ), + ) + bound_setattr("type", type) + bound_setattr("kw_only", kw_only) + bound_setattr("inherited", inherited) + bound_setattr("on_setattr", on_setattr) + bound_setattr("alias", alias) + + def __setattr__(self, name, value): + raise FrozenInstanceError + + @classmethod + def from_counting_attr(cls, name: str, ca: _CountingAttr, type=None): + # type holds the annotated value. deal with conflicts: + if type is None: + type = ca.type + elif ca.type is not None: + msg = f"Type annotation and type argument cannot both be present for '{name}'." + raise ValueError(msg) + return cls( + name, + ca._default, + ca._validator, + ca.repr, + None, + ca.hash, + ca.init, + False, + ca.metadata, + type, + ca.converter, + ca.kw_only, + ca.eq, + ca.eq_key, + ca.order, + ca.order_key, + ca.on_setattr, + ca.alias, + ) + + # Don't use attrs.evolve since fields(Attribute) doesn't work + def evolve(self, **changes): + """ + Copy *self* and apply *changes*. + + This works similarly to `attrs.evolve` but that function does not work + with :class:`attrs.Attribute`. + + It is mainly meant to be used for `transform-fields`. + + .. versionadded:: 20.3.0 + """ + new = copy.copy(self) + + new._setattrs(changes.items()) + + return new + + # Don't use _add_pickle since fields(Attribute) doesn't work + def __getstate__(self): + """ + Play nice with pickle. + """ + return tuple( + getattr(self, name) if name != "metadata" else dict(self.metadata) + for name in self.__slots__ + ) + + def __setstate__(self, state): + """ + Play nice with pickle. + """ + self._setattrs(zip(self.__slots__, state)) + + def _setattrs(self, name_values_pairs): + bound_setattr = _OBJ_SETATTR.__get__(self) + for name, value in name_values_pairs: + if name != "metadata": + bound_setattr(name, value) + else: + bound_setattr( + name, + ( + types.MappingProxyType(dict(value)) + if value + else _EMPTY_METADATA_SINGLETON + ), + ) + + +_a = [ + Attribute( + name=name, + default=NOTHING, + validator=None, + repr=True, + cmp=None, + eq=True, + order=False, + hash=(name != "metadata"), + init=True, + inherited=False, + alias=_default_init_alias_for(name), + ) + for name in Attribute.__slots__ +] + +Attribute = _add_hash( + _add_eq( + _add_repr(Attribute, attrs=_a), + attrs=[a for a in _a if a.name != "inherited"], + ), + attrs=[a for a in _a if a.hash and a.name != "inherited"], +) + + +class _CountingAttr: + """ + Intermediate representation of attributes that uses a counter to preserve + the order in which the attributes have been defined. + + *Internal* data structure of the attrs library. Running into is most + likely the result of a bug like a forgotten `@attr.s` decorator. + """ + + __slots__ = ( + "_default", + "_validator", + "alias", + "converter", + "counter", + "eq", + "eq_key", + "hash", + "init", + "kw_only", + "metadata", + "on_setattr", + "order", + "order_key", + "repr", + "type", + ) + __attrs_attrs__ = ( + *tuple( + Attribute( + name=name, + alias=_default_init_alias_for(name), + default=NOTHING, + validator=None, + repr=True, + cmp=None, + hash=True, + init=True, + kw_only=False, + eq=True, + eq_key=None, + order=False, + order_key=None, + inherited=False, + on_setattr=None, + ) + for name in ( + "counter", + "_default", + "repr", + "eq", + "order", + "hash", + "init", + "on_setattr", + "alias", + ) + ), + Attribute( + name="metadata", + alias="metadata", + default=None, + validator=None, + repr=True, + cmp=None, + hash=False, + init=True, + kw_only=False, + eq=True, + eq_key=None, + order=False, + order_key=None, + inherited=False, + on_setattr=None, + ), + ) + cls_counter = 0 + + def __init__( + self, + default, + validator, + repr, + cmp, + hash, + init, + converter, + metadata, + type, + kw_only, + eq, + eq_key, + order, + order_key, + on_setattr, + alias, + ): + _CountingAttr.cls_counter += 1 + self.counter = _CountingAttr.cls_counter + self._default = default + self._validator = validator + self.converter = converter + self.repr = repr + self.eq = eq + self.eq_key = eq_key + self.order = order + self.order_key = order_key + self.hash = hash + self.init = init + self.metadata = metadata + self.type = type + self.kw_only = kw_only + self.on_setattr = on_setattr + self.alias = alias + + def validator(self, meth): + """ + Decorator that adds *meth* to the list of validators. + + Returns *meth* unchanged. + + .. versionadded:: 17.1.0 + """ + if self._validator is None: + self._validator = meth + else: + self._validator = and_(self._validator, meth) + return meth + + def default(self, meth): + """ + Decorator that allows to set the default for an attribute. + + Returns *meth* unchanged. + + Raises: + DefaultAlreadySetError: If default has been set before. + + .. versionadded:: 17.1.0 + """ + if self._default is not NOTHING: + raise DefaultAlreadySetError + + self._default = Factory(meth, takes_self=True) + + return meth + + +_CountingAttr = _add_eq(_add_repr(_CountingAttr)) + + +class Factory: + """ + Stores a factory callable. + + If passed as the default value to `attrs.field`, the factory is used to + generate a new value. + + Args: + factory (typing.Callable): + A callable that takes either none or exactly one mandatory + positional argument depending on *takes_self*. + + takes_self (bool): + Pass the partially initialized instance that is being initialized + as a positional argument. + + .. versionadded:: 17.1.0 *takes_self* + """ + + __slots__ = ("factory", "takes_self") + + def __init__(self, factory, takes_self=False): + self.factory = factory + self.takes_self = takes_self + + def __getstate__(self): + """ + Play nice with pickle. + """ + return tuple(getattr(self, name) for name in self.__slots__) + + def __setstate__(self, state): + """ + Play nice with pickle. + """ + for name, value in zip(self.__slots__, state): + setattr(self, name, value) + + +_f = [ + Attribute( + name=name, + default=NOTHING, + validator=None, + repr=True, + cmp=None, + eq=True, + order=False, + hash=True, + init=True, + inherited=False, + ) + for name in Factory.__slots__ +] + +Factory = _add_hash(_add_eq(_add_repr(Factory, attrs=_f), attrs=_f), attrs=_f) + + +class Converter: + """ + Stores a converter callable. + + Allows for the wrapped converter to take additional arguments. The + arguments are passed in the order they are documented. + + Args: + converter (Callable): A callable that converts the passed value. + + takes_self (bool): + Pass the partially initialized instance that is being initialized + as a positional argument. (default: `False`) + + takes_field (bool): + Pass the field definition (an :class:`Attribute`) into the + converter as a positional argument. (default: `False`) + + .. versionadded:: 24.1.0 + """ + + __slots__ = ( + "__call__", + "_first_param_type", + "_global_name", + "converter", + "takes_field", + "takes_self", + ) + + def __init__(self, converter, *, takes_self=False, takes_field=False): + self.converter = converter + self.takes_self = takes_self + self.takes_field = takes_field + + ex = _AnnotationExtractor(converter) + self._first_param_type = ex.get_first_param_type() + + if not (self.takes_self or self.takes_field): + self.__call__ = lambda value, _, __: self.converter(value) + elif self.takes_self and not self.takes_field: + self.__call__ = lambda value, instance, __: self.converter( + value, instance + ) + elif not self.takes_self and self.takes_field: + self.__call__ = lambda value, __, field: self.converter( + value, field + ) + else: + self.__call__ = lambda value, instance, field: self.converter( + value, instance, field + ) + + rt = ex.get_return_type() + if rt is not None: + self.__call__.__annotations__["return"] = rt + + @staticmethod + def _get_global_name(attr_name: str) -> str: + """ + Return the name that a converter for an attribute name *attr_name* + would have. + """ + return f"__attr_converter_{attr_name}" + + def _fmt_converter_call(self, attr_name: str, value_var: str) -> str: + """ + Return a string that calls the converter for an attribute name + *attr_name* and the value in variable named *value_var* according to + `self.takes_self` and `self.takes_field`. + """ + if not (self.takes_self or self.takes_field): + return f"{self._get_global_name(attr_name)}({value_var})" + + if self.takes_self and self.takes_field: + return f"{self._get_global_name(attr_name)}({value_var}, self, attr_dict['{attr_name}'])" + + if self.takes_self: + return f"{self._get_global_name(attr_name)}({value_var}, self)" + + return f"{self._get_global_name(attr_name)}({value_var}, attr_dict['{attr_name}'])" + + def __getstate__(self): + """ + Return a dict containing only converter and takes_self -- the rest gets + computed when loading. + """ + return { + "converter": self.converter, + "takes_self": self.takes_self, + "takes_field": self.takes_field, + } + + def __setstate__(self, state): + """ + Load instance from state. + """ + self.__init__(**state) + + +_f = [ + Attribute( + name=name, + default=NOTHING, + validator=None, + repr=True, + cmp=None, + eq=True, + order=False, + hash=True, + init=True, + inherited=False, + ) + for name in ("converter", "takes_self", "takes_field") +] + +Converter = _add_hash( + _add_eq(_add_repr(Converter, attrs=_f), attrs=_f), attrs=_f +) + + +def make_class( + name, attrs, bases=(object,), class_body=None, **attributes_arguments +): + r""" + A quick way to create a new class called *name* with *attrs*. + + .. note:: + + ``make_class()`` is a thin wrapper around `attr.s`, not `attrs.define` + which means that it doesn't come with some of the improved defaults. + + For example, if you want the same ``on_setattr`` behavior as in + `attrs.define`, you have to pass the hooks yourself: ``make_class(..., + on_setattr=setters.pipe(setters.convert, setters.validate)`` + + .. warning:: + + It is *your* duty to ensure that the class name and the attribute names + are valid identifiers. ``make_class()`` will *not* validate them for + you. + + Args: + name (str): The name for the new class. + + attrs (list | dict): + A list of names or a dictionary of mappings of names to `attr.ib`\ + s / `attrs.field`\ s. + + The order is deduced from the order of the names or attributes + inside *attrs*. Otherwise the order of the definition of the + attributes is used. + + bases (tuple[type, ...]): Classes that the new class will subclass. + + class_body (dict): + An optional dictionary of class attributes for the new class. + + attributes_arguments: Passed unmodified to `attr.s`. + + Returns: + type: A new class with *attrs*. + + .. versionadded:: 17.1.0 *bases* + .. versionchanged:: 18.1.0 If *attrs* is ordered, the order is retained. + .. versionchanged:: 23.2.0 *class_body* + .. versionchanged:: 25.2.0 Class names can now be unicode. + """ + # Class identifiers are converted into the normal form NFKC while parsing + name = unicodedata.normalize("NFKC", name) + + if isinstance(attrs, dict): + cls_dict = attrs + elif isinstance(attrs, (list, tuple)): + cls_dict = {a: attrib() for a in attrs} + else: + msg = "attrs argument must be a dict or a list." + raise TypeError(msg) + + pre_init = cls_dict.pop("__attrs_pre_init__", None) + post_init = cls_dict.pop("__attrs_post_init__", None) + user_init = cls_dict.pop("__init__", None) + + body = {} + if class_body is not None: + body.update(class_body) + if pre_init is not None: + body["__attrs_pre_init__"] = pre_init + if post_init is not None: + body["__attrs_post_init__"] = post_init + if user_init is not None: + body["__init__"] = user_init + + type_ = types.new_class(name, bases, {}, lambda ns: ns.update(body)) + + # For pickling to work, the __module__ variable needs to be set to the + # frame where the class is created. Bypass this step in environments where + # sys._getframe is not defined (Jython for example) or sys._getframe is not + # defined for arguments greater than 0 (IronPython). + with contextlib.suppress(AttributeError, ValueError): + type_.__module__ = sys._getframe(1).f_globals.get( + "__name__", "__main__" + ) + + # We do it here for proper warnings with meaningful stacklevel. + cmp = attributes_arguments.pop("cmp", None) + ( + attributes_arguments["eq"], + attributes_arguments["order"], + ) = _determine_attrs_eq_order( + cmp, + attributes_arguments.get("eq"), + attributes_arguments.get("order"), + True, + ) + + cls = _attrs(these=cls_dict, **attributes_arguments)(type_) + # Only add type annotations now or "_attrs()" will complain: + cls.__annotations__ = { + k: v.type for k, v in cls_dict.items() if v.type is not None + } + return cls + + +# These are required by within this module so we define them here and merely +# import into .validators / .converters. + + +@attrs(slots=True, unsafe_hash=True) +class _AndValidator: + """ + Compose many validators to a single one. + """ + + _validators = attrib() + + def __call__(self, inst, attr, value): + for v in self._validators: + v(inst, attr, value) + + +def and_(*validators): + """ + A validator that composes multiple validators into one. + + When called on a value, it runs all wrapped validators. + + Args: + validators (~collections.abc.Iterable[typing.Callable]): + Arbitrary number of validators. + + .. versionadded:: 17.1.0 + """ + vals = [] + for validator in validators: + vals.extend( + validator._validators + if isinstance(validator, _AndValidator) + else [validator] + ) + + return _AndValidator(tuple(vals)) + + +def pipe(*converters): + """ + A converter that composes multiple converters into one. + + When called on a value, it runs all wrapped converters, returning the + *last* value. + + Type annotations will be inferred from the wrapped converters', if they + have any. + + converters (~collections.abc.Iterable[typing.Callable]): + Arbitrary number of converters. + + .. versionadded:: 20.1.0 + """ + + return_instance = any(isinstance(c, Converter) for c in converters) + + if return_instance: + + def pipe_converter(val, inst, field): + for c in converters: + val = ( + c(val, inst, field) if isinstance(c, Converter) else c(val) + ) + + return val + + else: + + def pipe_converter(val): + for c in converters: + val = c(val) + + return val + + if not converters: + # If the converter list is empty, pipe_converter is the identity. + A = TypeVar("A") + pipe_converter.__annotations__.update({"val": A, "return": A}) + else: + # Get parameter type from first converter. + t = _AnnotationExtractor(converters[0]).get_first_param_type() + if t: + pipe_converter.__annotations__["val"] = t + + last = converters[-1] + if not PY_3_11_PLUS and isinstance(last, Converter): + last = last.__call__ + + # Get return type from last converter. + rt = _AnnotationExtractor(last).get_return_type() + if rt: + pipe_converter.__annotations__["return"] = rt + + if return_instance: + return Converter(pipe_converter, takes_self=True, takes_field=True) + return pipe_converter |