-
-
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attrs metadata is not None coverage
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Note the lost coverage for 137->139. | |
Run against https://github.com/python-attrs/attrs/tree/2ac7eaec528acc18a70afae67ac7bf68a3d1ae21. | |
Came up during https://github.com/python-attrs/attrs/pull/280#issuecomment-347247930. |
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~/attr/attrs2 t278_independent_countingattr_metadata git clean -fdx; git status; git rev-parse HEAD; git diff; tox -e py36,coverage-report | |
Removing .tox/ | |
Removing src/attrs.egg-info/ | |
On branch t278_independent_countingattr_metadata | |
Your branch is up-to-date with 'origin/t278_independent_countingattr_metadata'. | |
nothing to commit, working tree clean | |
2ac7eaec528acc18a70afae67ac7bf68a3d1ae21 | |
GLOB sdist-make: /home/altendky/attrs/attrs2/setup.py | |
py36 create: /home/altendky/attrs/attrs2/.tox/py36 | |
py36 installdeps: -rdev-requirements.txt | |
py36 inst: /home/altendky/attrs/attrs2/.tox/dist/attrs-17.4.0.dev0.zip | |
py36 installed: attrs==17.4.0.dev0,coverage==4.4.2,hypothesis==3.44.1,pluggy==0.6.0,py==1.5.2,Pympler==0.5,pytest==3.3.1,six==1.11.0,zope.interface==4.4.3 | |
py36 runtests: PYTHONHASHSEED='2273239456' | |
py36 runtests: commands[0] | coverage run --parallel -m pytest | |
===================================================================== test session starts ====================================================================== | |
platform linux -- Python 3.6.3, pytest-3.3.1, py-1.5.2, pluggy-0.6.0 | |
rootdir: /home/altendky/attrs/attrs2, inifile: setup.cfg | |
plugins: hypothesis-3.44.1 | |
collected 318 items | |
tests/test_annotations.py .......... [ 3%] | |
tests/test_config.py .... [ 4%] | |
tests/test_converters.py ... [ 5%] | |
tests/test_dark_magic.py .............................................................................................. [ 34%] | |
tests/test_dunders.py ................................................... [ 50%] | |
tests/test_filters.py ................. [ 56%] | |
tests/test_funcs.py ................................... [ 67%] | |
tests/test_init_subclass.py ... [ 68%] | |
tests/test_make.py ...............s.................................................... [ 89%] | |
tests/test_slots.py ........... [ 93%] | |
tests/test_validators.py ...................... [100%] | |
=================================================================== short test summary info ==================================================================== | |
SKIP [1] tests/test_make.py:253: No old-style classes in Py3 | |
============================================================ 317 passed, 1 skipped in 34.44 seconds ============================================================ | |
coverage-report create: /home/altendky/attrs/attrs2/.tox/coverage-report | |
coverage-report installdeps: coverage | |
coverage-report installed: coverage==4.4.2 | |
coverage-report runtests: PYTHONHASHSEED='2273239456' | |
coverage-report runtests: commands[0] | coverage combine | |
coverage-report runtests: commands[1] | coverage report | |
Name Stmts Miss Branch BrPart Cover Missing | |
-------------------------------------------------------------------- | |
src/attr/__init__.py 19 0 0 0 100% | |
src/attr/_compat.py 54 27 4 1 52% 14-75, 13->14 | |
src/attr/_config.py 9 0 2 0 100% | |
src/attr/_funcs.py 68 0 42 0 100% | |
src/attr/_make.py 505 4 236 4 99% 616, 660-665, 869, 420->423, 615->616, 659->660, 866->869 | |
src/attr/converters.py 7 0 2 0 100% | |
src/attr/exceptions.py 8 0 0 0 100% | |
src/attr/filters.py 15 0 3 0 100% | |
src/attr/validators.py 46 0 18 0 100% | |
-------------------------------------------------------------------- | |
TOTAL 731 31 307 5 97% | |
___________________________________________________________________________ summary ____________________________________________________________________________ | |
py36: commands succeeded | |
coverage-report: commands succeeded | |
congratulations :) | |
~/attr/attrs2 t278_independent_countingattr_metadata |
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~/attr/attrs2 t278_independent_countingattr_metadata ● git clean -fdx; git status; git rev-parse HEAD; git diff; tox -e py36,coverage-report | |
Removing .coverage | |
Removing .hypothesis/ | |
Removing .idea/ | |
Removing .tox/ | |
Removing __pycache__/ | |
Removing src/attrs.egg-info/ | |
Removing tests/__pycache__/ | |
On branch t278_independent_countingattr_metadata | |
Your branch is up-to-date with 'origin/t278_independent_countingattr_metadata'. | |
Changes not staged for commit: | |
(use "git add <file>..." to update what will be committed) | |
(use "git checkout -- <file>..." to discard changes in working directory) | |
modified: tests/test_make.py | |
no changes added to commit (use "git add" and/or "git commit -a") | |
2ac7eaec528acc18a70afae67ac7bf68a3d1ae21 | |
diff --git a/tests/test_make.py b/tests/test_make.py | |
index 256c03f..e54f580 100644 | |
--- a/tests/test_make.py | |
+++ b/tests/test_make.py | |
@@ -845,13 +845,6 @@ class TestMetadata(object): | |
assert cls_a.metadata != {} | |
assert cls_a.metadata == raw_a.metadata | |
- def test_not_none_metadata_force_coverage(self): | |
- """ | |
- Force coverage of metadata is not None case even though other tests | |
- should do so anyways. | |
- """ | |
- attr.ib(metadata={}) | |
- | |
class TestClassBuilder(object): | |
""" | |
GLOB sdist-make: /home/altendky/attrs/attrs2/setup.py | |
py36 create: /home/altendky/attrs/attrs2/.tox/py36 | |
py36 installdeps: -rdev-requirements.txt | |
py36 inst: /home/altendky/attrs/attrs2/.tox/dist/attrs-17.4.0.dev0.zip | |
py36 installed: attrs==17.4.0.dev0,coverage==4.4.2,hypothesis==3.44.1,pluggy==0.6.0,py==1.5.2,Pympler==0.5,pytest==3.3.1,six==1.11.0,zope.interface==4.4.3 | |
py36 runtests: PYTHONHASHSEED='1215129075' | |
py36 runtests: commands[0] | coverage run --parallel -m pytest | |
===================================================================== test session starts ====================================================================== | |
platform linux -- Python 3.6.3, pytest-3.3.1, py-1.5.2, pluggy-0.6.0 | |
rootdir: /home/altendky/attrs/attrs2, inifile: setup.cfg | |
plugins: hypothesis-3.44.1 | |
collected 317 items | |
tests/test_annotations.py .......... [ 3%] | |
tests/test_config.py .... [ 4%] | |
tests/test_converters.py ... [ 5%] | |
tests/test_dark_magic.py .............................................................................................. [ 35%] | |
tests/test_dunders.py ................................................... [ 51%] | |
tests/test_filters.py ................. [ 56%] | |
tests/test_funcs.py ................................... [ 67%] | |
tests/test_init_subclass.py ... [ 68%] | |
tests/test_make.py ...............s................................................... [ 89%] | |
tests/test_slots.py ........... [ 93%] | |
tests/test_validators.py ...................... [100%] | |
=================================================================== short test summary info ==================================================================== | |
SKIP [1] tests/test_make.py:253: No old-style classes in Py3 | |
============================================================ 316 passed, 1 skipped in 44.16 seconds ============================================================ | |
coverage-report create: /home/altendky/attrs/attrs2/.tox/coverage-report | |
coverage-report installdeps: coverage | |
coverage-report installed: coverage==4.4.2 | |
coverage-report runtests: PYTHONHASHSEED='1215129075' | |
coverage-report runtests: commands[0] | coverage combine | |
coverage-report runtests: commands[1] | coverage report | |
Name Stmts Miss Branch BrPart Cover Missing | |
-------------------------------------------------------------------- | |
src/attr/__init__.py 19 0 0 0 100% | |
src/attr/_compat.py 54 27 4 1 52% 14-75, 13->14 | |
src/attr/_config.py 9 0 2 0 100% | |
src/attr/_funcs.py 68 0 42 0 100% | |
src/attr/_make.py 505 4 236 5 99% 616, 660-665, 869, 137->139, 420->423, 615->616, 659->660, 866->869 | |
src/attr/converters.py 7 0 2 0 100% | |
src/attr/exceptions.py 8 0 0 0 100% | |
src/attr/filters.py 15 0 3 0 100% | |
src/attr/validators.py 46 0 18 0 100% | |
-------------------------------------------------------------------- | |
TOTAL 731 31 307 6 96% | |
___________________________________________________________________________ summary ____________________________________________________________________________ | |
py36: commands succeeded | |
coverage-report: commands succeeded | |
congratulations :) | |
~/attr/attrs2 t278_independent_countingattr_metadata ● |
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from __future__ import absolute_import, division, print_function | |
import hashlib | |
import linecache | |
import sys | |
from operator import itemgetter | |
from . import _config | |
from ._compat import PY2, isclass, iteritems, metadata_proxy, set_closure_cell | |
from .exceptions import ( | |
DefaultAlreadySetError, FrozenInstanceError, NotAnAttrsClassError, | |
UnannotatedAttributeError | |
) | |
# This is used at least twice, so cache it here. | |
_obj_setattr = object.__setattr__ | |
_init_convert_pat = "__attr_convert_{}" | |
_init_factory_pat = "__attr_factory_{}" | |
_tuple_property_pat = " {attr_name} = property(itemgetter({index}))" | |
_empty_metadata_singleton = metadata_proxy({}) | |
class _Nothing(object): | |
""" | |
Sentinel class to indicate the lack of a value when ``None`` is ambiguous. | |
All instances of `_Nothing` are equal. | |
""" | |
def __copy__(self): | |
return self | |
def __deepcopy__(self, _): | |
return self | |
def __eq__(self, other): | |
return other.__class__ == _Nothing | |
def __ne__(self, other): | |
return not self == other | |
def __repr__(self): | |
return "NOTHING" | |
def __hash__(self): | |
return 0xdeadbeef | |
NOTHING = _Nothing() | |
""" | |
Sentinel to indicate the lack of a value when ``None`` is ambiguous. | |
""" | |
def attrib(default=NOTHING, validator=None, | |
repr=True, cmp=True, hash=None, init=True, | |
convert=None, metadata=None, type=None): | |
""" | |
Create a new attribute on a class. | |
.. warning:: | |
Does *not* do anything unless the class is also decorated with | |
:func:`attr.s`! | |
:param default: A value that is used if an ``attrs``-generated ``__init__`` | |
is used and no value is passed while instantiating or the attribute is | |
excluded using ``init=False``. | |
If the value is an instance of :class:`Factory`, its callable will be | |
used to construct a new value (useful for mutable data types like lists | |
or dicts). | |
If a default is not set (or set manually to ``attr.NOTHING``), a value | |
*must* be supplied when instantiating; otherwise a :exc:`TypeError` | |
will be raised. | |
The default can also be set using decorator notation as shown below. | |
:type default: Any value. | |
:param validator: :func:`callable` that is called by ``attrs``-generated | |
``__init__`` methods after the instance has been initialized. They | |
receive the initialized instance, the :class:`Attribute`, and the | |
passed value. | |
The return value is *not* inspected so the validator has to throw an | |
exception itself. | |
If a ``list`` is passed, its items are treated as validators and must | |
all pass. | |
Validators can be globally disabled and re-enabled using | |
:func:`get_run_validators`. | |
The validator can also be set using decorator notation as shown below. | |
:type validator: ``callable`` or a ``list`` of ``callable``\ s. | |
:param bool repr: Include this attribute in the generated ``__repr__`` | |
method. | |
:param bool cmp: Include this attribute in the generated comparison methods | |
(``__eq__`` et al). | |
:param hash: Include this attribute in the generated ``__hash__`` | |
method. If ``None`` (default), mirror *cmp*'s value. This is the | |
correct behavior according the Python spec. Setting this value to | |
anything else than ``None`` is *discouraged*. | |
:type hash: ``bool`` or ``None`` | |
:param bool init: Include this attribute in the generated ``__init__`` | |
method. It is possible to set this to ``False`` and set a default | |
value. In that case this attributed is unconditionally initialized | |
with the specified default value or factory. | |
:param callable convert: :func:`callable` that is called by | |
``attrs``-generated ``__init__`` methods to convert attribute's value | |
to the desired format. It is given the passed-in value, and the | |
returned value will be used as the new value of the attribute. The | |
value is converted before being passed to the validator, if any. | |
:param metadata: An arbitrary mapping, to be used by third-party | |
components. See :ref:`extending_metadata`. | |
:param type: The type of the attribute. In Python 3.6 or greater, the | |
preferred method to specify the type is using a variable annotation | |
(see `PEP 526 <https://www.python.org/dev/peps/pep-0526/>`_). | |
This argument is provided for backward compatibility. | |
Regardless of the approach used, the type will be stored on | |
``Attribute.type``. | |
.. versionchanged:: 17.1.0 *validator* can be a ``list`` now. | |
.. versionchanged:: 17.1.0 | |
*hash* is ``None`` and therefore mirrors *cmp* by default. | |
.. versionadded:: 17.3.0 *type* | |
""" | |
if hash is not None and hash is not True and hash is not False: | |
raise TypeError( | |
"Invalid value for hash. Must be True, False, or None." | |
) | |
if metadata is None: | |
metadata = {} | |
return _CountingAttr( | |
default=default, | |
validator=validator, | |
repr=repr, | |
cmp=cmp, | |
hash=hash, | |
init=init, | |
convert=convert, | |
metadata=metadata, | |
type=type, | |
) | |
def _make_attr_tuple_class(cls_name, attr_names): | |
""" | |
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 = "{}Attributes".format(cls_name) | |
attr_class_template = [ | |
"class {}(tuple):".format(attr_class_name), | |
" __slots__ = ()", | |
] | |
if attr_names: | |
for i, attr_name in enumerate(attr_names): | |
attr_class_template.append(_tuple_property_pat.format( | |
index=i, | |
attr_name=attr_name, | |
)) | |
else: | |
attr_class_template.append(" pass") | |
globs = {"itemgetter": itemgetter} | |
eval(compile("\n".join(attr_class_template), "", "exec"), globs) | |
return globs[attr_class_name] | |
# Tuple class for extracted attributes from a class definition. | |
# `super_attrs` is a subset of `attrs`. | |
_Attributes = _make_attr_tuple_class("_Attributes", [ | |
"attrs", # all attributes to build dunder methods for | |
"super_attrs", # attributes that have been inherited from super classes | |
]) | |
def _is_class_var(annot): | |
""" | |
Check whether *annot* is a typing.ClassVar. | |
The implementation is gross but importing `typing` is slow and there are | |
discussions to remove it from the stdlib alltogether. | |
""" | |
return str(annot).startswith("typing.ClassVar") | |
def _get_annotations(cls): | |
""" | |
Get annotations for *cls*. | |
""" | |
anns = getattr(cls, "__annotations__", None) | |
if anns is None: | |
return {} | |
# Verify that the annotations aren't merely inherited. | |
for super_cls in cls.__mro__[1:]: | |
if anns is getattr(super_cls, "__annotations__", None): | |
return {} | |
return anns | |
def _transform_attrs(cls, these, auto_attribs): | |
""" | |
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. | |
Return an `_Attributes`. | |
""" | |
cd = cls.__dict__ | |
anns = _get_annotations(cls) | |
if these is not None: | |
ca_list = sorted(( | |
(name, ca) | |
for name, ca | |
in iteritems(these) | |
), key=lambda e: e[1].counter) | |
elif auto_attribs is True: | |
ca_names = { | |
name | |
for name, attr | |
in cd.items() | |
if isinstance(attr, _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 not isinstance(a, _CountingAttr): | |
if a is NOTHING: | |
a = attrib() | |
else: | |
a = attrib(default=a) | |
ca_list.append((attr_name, a)) | |
unannotated = ca_names - annot_names | |
if len(unannotated) > 0: | |
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 isinstance(attr, _CountingAttr) | |
), key=lambda e: e[1].counter) | |
own_attrs = [ | |
Attribute.from_counting_attr( | |
name=attr_name, | |
ca=ca, | |
type=anns.get(attr_name), | |
) | |
for attr_name, ca | |
in ca_list | |
] | |
super_attrs = [] | |
taken_attr_names = {a.name: a for a in own_attrs} | |
# Traverse the MRO and collect attributes. | |
for super_cls in cls.__mro__[1:-1]: | |
sub_attrs = getattr(super_cls, "__attrs_attrs__", None) | |
if sub_attrs is not None: | |
for a in sub_attrs: | |
prev_a = taken_attr_names.get(a.name) | |
# Only add an attribute if it hasn't been defined before. This | |
# allows for overwriting attribute definitions by subclassing. | |
if prev_a is None: | |
super_attrs.append(a) | |
taken_attr_names[a.name] = a | |
attr_names = [a.name for a in super_attrs + own_attrs] | |
AttrsClass = _make_attr_tuple_class(cls.__name__, attr_names) | |
attrs = AttrsClass( | |
super_attrs + [ | |
Attribute.from_counting_attr( | |
name=attr_name, | |
ca=ca, | |
type=anns.get(attr_name) | |
) | |
for attr_name, ca | |
in ca_list | |
] | |
) | |
had_default = False | |
for a in attrs: | |
if had_default is True and a.default is NOTHING and a.init is True: | |
raise ValueError( | |
"No mandatory attributes allowed after an attribute with a " | |
"default value or factory. Attribute in question: {a!r}" | |
.format(a=a) | |
) | |
elif had_default is False and \ | |
a.default is not NOTHING and \ | |
a.init is not False: | |
had_default = True | |
return _Attributes((attrs, super_attrs)) | |
def _frozen_setattrs(self, name, value): | |
""" | |
Attached to frozen classes as __setattr__. | |
""" | |
raise FrozenInstanceError() | |
def _frozen_delattrs(self, name): | |
""" | |
Attached to frozen classes as __delattr__. | |
""" | |
raise FrozenInstanceError() | |
class _ClassBuilder(object): | |
""" | |
Iteratively build *one* class. | |
""" | |
__slots__ = ( | |
"_cls", "_cls_dict", "_attrs", "_super_names", "_attr_names", "_slots", | |
"_frozen", "_has_post_init", | |
) | |
def __init__(self, cls, these, slots, frozen, auto_attribs): | |
attrs, super_attrs = _transform_attrs(cls, these, auto_attribs) | |
self._cls = cls | |
self._cls_dict = dict(cls.__dict__) if slots else {} | |
self._attrs = attrs | |
self._super_names = set(a.name for a in super_attrs) | |
self._attr_names = tuple(a.name for a in attrs) | |
self._slots = slots | |
self._frozen = frozen or _has_frozen_superclass(cls) | |
self._has_post_init = bool(getattr(cls, "__attrs_post_init__", False)) | |
self._cls_dict["__attrs_attrs__"] = self._attrs | |
if frozen: | |
self._cls_dict["__setattr__"] = _frozen_setattrs | |
self._cls_dict["__delattr__"] = _frozen_delattrs | |
def __repr__(self): | |
return "<_ClassBuilder(cls={cls})>".format(cls=self._cls.__name__) | |
def build_class(self): | |
""" | |
Finalize class based on the accumulated configuration. | |
Builder cannot be used anymore after calling this method. | |
""" | |
if self._slots is True: | |
return self._create_slots_class() | |
else: | |
return self._patch_original_class() | |
def _patch_original_class(self): | |
""" | |
Apply accumulated methods and return the class. | |
""" | |
cls = self._cls | |
super_names = self._super_names | |
# Clean class of attribute definitions (`attr.ib()`s). | |
for name in self._attr_names: | |
if name not in super_names and \ | |
getattr(cls, name, None) is not None: | |
delattr(cls, name) | |
# Attach our dunder methods. | |
for name, value in self._cls_dict.items(): | |
setattr(cls, name, value) | |
return cls | |
def _create_slots_class(self): | |
""" | |
Build and return a new class with a `__slots__` attribute. | |
""" | |
super_names = self._super_names | |
cd = { | |
k: v | |
for k, v in iteritems(self._cls_dict) | |
if k not in tuple(self._attr_names) + ("__dict__",) | |
} | |
# We only add the names of attributes that aren't inherited. | |
# Settings __slots__ to inherited attributes wastes memory. | |
cd["__slots__"] = tuple( | |
name | |
for name in self._attr_names | |
if name not in super_names | |
) | |
qualname = getattr(self._cls, "__qualname__", None) | |
if qualname is not None: | |
cd["__qualname__"] = qualname | |
attr_names = tuple(self._attr_names) | |
def slots_getstate(self): | |
""" | |
Automatically created by attrs. | |
""" | |
return tuple(getattr(self, name) for name in attr_names) | |
def slots_setstate(self, state): | |
""" | |
Automatically created by attrs. | |
""" | |
__bound_setattr = _obj_setattr.__get__(self, Attribute) | |
for name, value in zip(attr_names, state): | |
__bound_setattr(name, value) | |
# slots and frozen require __getstate__/__setstate__ to work | |
cd["__getstate__"] = slots_getstate | |
cd["__setstate__"] = slots_setstate | |
# 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. On Python 3, | |
# 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 cls.__dict__.values(): | |
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) | |
else: | |
closure_cells = getattr(item, "__closure__", None) | |
if not closure_cells: # Catch None or the empty list. | |
continue | |
for cell in closure_cells: | |
if cell.cell_contents is self._cls: | |
set_closure_cell(cell, cls) | |
return cls | |
def add_repr(self, ns): | |
self._cls_dict["__repr__"] = _make_repr(self._attrs, ns=ns) | |
return self | |
def add_str(self): | |
repr_ = self._cls_dict.get("__repr__") | |
if repr_ is None: | |
raise ValueError( | |
"__str__ can only be generated if a __repr__ exists." | |
) | |
self._cls_dict["__str__"] = repr_ | |
return self | |
def make_unhashable(self): | |
self._cls_dict["__hash__"] = None | |
return self | |
def add_hash(self): | |
self._cls_dict["__hash__"] = _make_hash(self._attrs) | |
return self | |
def add_init(self): | |
self._cls_dict["__init__"] = _make_init( | |
self._attrs, | |
self._has_post_init, | |
self._frozen, | |
) | |
return self | |
def add_cmp(self): | |
cd = self._cls_dict | |
cd["__eq__"], cd["__ne__"], cd["__lt__"], cd["__le__"], cd["__gt__"], \ | |
cd["__ge__"] = _make_cmp(self._attrs) | |
return self | |
def attrs(maybe_cls=None, these=None, repr_ns=None, | |
repr=True, cmp=True, hash=None, init=True, | |
slots=False, frozen=False, str=False, auto_attribs=False): | |
r""" | |
A class decorator that adds `dunder | |
<https://wiki.python.org/moin/DunderAlias>`_\ -methods according to the | |
specified attributes using :func:`attr.ib` or the *these* argument. | |
:param these: A dictionary of name to :func:`attr.ib` mappings. This is | |
useful to avoid the definition of your attributes within the class body | |
because you can't (e.g. if you want to add ``__repr__`` methods to | |
Django models) or don't want to. | |
If *these* is not ``None``, ``attrs`` will *not* search the class body | |
for attributes. | |
:type these: :class:`dict` of :class:`str` to :func:`attr.ib` | |
:param str repr_ns: When using nested classes, there's no way in Python 2 | |
to automatically detect that. Therefore it's possible to set the | |
namespace explicitly for a more meaningful ``repr`` output. | |
:param bool repr: Create a ``__repr__`` method with a human readable | |
representation of ``attrs`` attributes.. | |
:param bool str: Create a ``__str__`` method that is identical to | |
``__repr__``. This is usually not necessary except for | |
:class:`Exception`\ s. | |
:param bool cmp: Create ``__eq__``, ``__ne__``, ``__lt__``, ``__le__``, | |
``__gt__``, and ``__ge__`` methods that compare the class as if it were | |
a tuple of its ``attrs`` attributes. But the attributes are *only* | |
compared, if the type of both classes is *identical*! | |
:param hash: If ``None`` (default), the ``__hash__`` method is generated | |
according how *cmp* and *frozen* are set. | |
1. If *both* are True, ``attrs`` will generate a ``__hash__`` for you. | |
2. If *cmp* is True and *frozen* is False, ``__hash__`` will be set to | |
None, marking it unhashable (which it is). | |
3. If *cmp* is False, ``__hash__`` will be left untouched meaning the | |
``__hash__`` method of the superclass will be used (if superclass is | |
``object``, this means it will fall back to id-based hashing.). | |
Although not recommended, you can decide for yourself and force | |
``attrs`` to create one (e.g. if the class is immutable even though you | |
didn't freeze it programmatically) by passing ``True`` or not. Both of | |
these cases are rather special and should be used carefully. | |
See the `Python documentation \ | |
<https://docs.python.org/3/reference/datamodel.html#object.__hash__>`_ | |
and the `GitHub issue that led to the default behavior \ | |
<https://github.com/python-attrs/attrs/issues/136>`_ for more details. | |
:type hash: ``bool`` or ``None`` | |
:param bool init: Create a ``__init__`` method that initializes the | |
``attrs`` attributes. Leading underscores are stripped for the | |
argument name. If a ``__attrs_post_init__`` method exists on the | |
class, it will be called after the class is fully initialized. | |
:param bool slots: Create a slots_-style class that's more | |
memory-efficient. See :ref:`slots` for further ramifications. | |
:param bool frozen: Make instances immutable after initialization. If | |
someone attempts to modify a frozen instance, | |
:exc:`attr.exceptions.FrozenInstanceError` is raised. | |
Please note: | |
1. This is achieved by installing a custom ``__setattr__`` method | |
on your class so you can't implement an own one. | |
2. True immutability is impossible in Python. | |
3. This *does* have a minor a runtime performance :ref:`impact | |
<how-frozen>` when initializing new instances. In other words: | |
``__init__`` is slightly slower with ``frozen=True``. | |
4. If a class is frozen, you cannot modify ``self`` in | |
``__attrs_post_init__`` or a self-written ``__init__``. You can | |
circumvent that limitation by using | |
``object.__setattr__(self, "attribute_name", value)``. | |
.. _slots: https://docs.python.org/3/reference/datamodel.html#slots | |
:param bool auto_attribs: If True, collect `PEP 526`_-annotated attributes | |
(Python 3.6 and later only) from the class body. | |
In this case, you **must** annotate every field. If ``attrs`` | |
encounters a field that is set to an :func:`attr.ib` but lacks a type | |
annotation, an :exc:`attr.exceptions.UnannotatedAttributeError` is | |
raised. Use ``field_name: typing.Any = attr.ib(...)`` if you don't | |
want to set a type. | |
If you assign a value to those attributes (e.g. ``x: int = 42``), that | |
value becomes the default value like if it were passed using | |
``attr.ib(default=42)``. Passing an instance of :class:`Factory` also | |
works as expected. | |
Attributes annotated as :data:`typing.ClassVar` are **ignored**. | |
.. _`PEP 526`: https://www.python.org/dev/peps/pep-0526/ | |
.. versionadded:: 16.0.0 *slots* | |
.. versionadded:: 16.1.0 *frozen* | |
.. versionadded:: 16.3.0 *str*, and 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* | |
""" | |
def wrap(cls): | |
if getattr(cls, "__class__", None) is None: | |
raise TypeError("attrs only works with new-style classes.") | |
builder = _ClassBuilder(cls, these, slots, frozen, auto_attribs) | |
if repr is True: | |
builder.add_repr(repr_ns) | |
if str is True: | |
builder.add_str() | |
if cmp is True: | |
builder.add_cmp() | |
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. | |
raise TypeError( | |
"Invalid value for hash. Must be True, False, or None." | |
) | |
elif hash is False or (hash is None and cmp is False): | |
pass | |
elif hash is True or (hash is None and cmp is True and frozen is True): | |
builder.add_hash() | |
else: | |
builder.make_unhashable() | |
if init is True: | |
builder.add_init() | |
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 | |
else: | |
return wrap(maybe_cls) | |
_attrs = attrs | |
""" | |
Internal alias so we can use it in functions that take an argument called | |
*attrs*. | |
""" | |
if PY2: | |
def _has_frozen_superclass(cls): | |
""" | |
Check whether *cls* has a frozen ancestor by looking at its | |
__setattr__. | |
""" | |
return ( | |
getattr( | |
cls.__setattr__, "__module__", None | |
) == _frozen_setattrs.__module__ and | |
cls.__setattr__.__name__ == _frozen_setattrs.__name__ | |
) | |
else: | |
def _has_frozen_superclass(cls): | |
""" | |
Check whether *cls* has a frozen ancestor by looking at its | |
__setattr__. | |
""" | |
return cls.__setattr__ == _frozen_setattrs | |
def _attrs_to_tuple(obj, attrs): | |
""" | |
Create a tuple of all values of *obj*'s *attrs*. | |
""" | |
return tuple(getattr(obj, a.name) for a in attrs) | |
def _make_hash(attrs): | |
attrs = tuple( | |
a | |
for a in attrs | |
if a.hash is True or (a.hash is None and a.cmp is True) | |
) | |
# We cache the generated hash methods for the same kinds of attributes. | |
sha1 = hashlib.sha1() | |
sha1.update(repr(attrs).encode("utf-8")) | |
unique_filename = "<attrs generated hash %s>" % (sha1.hexdigest(),) | |
type_hash = hash(unique_filename) | |
lines = [ | |
"def __hash__(self):", | |
" return hash((", | |
" %d," % (type_hash,), | |
] | |
for a in attrs: | |
lines.append(" self.%s," % (a.name)) | |
lines.append(" ))") | |
script = "\n".join(lines) | |
globs = {} | |
locs = {} | |
bytecode = compile(script, unique_filename, "exec") | |
eval(bytecode, globs, locs) | |
# In order of debuggers like PDB being able to step through the code, | |
# we add a fake linecache entry. | |
linecache.cache[unique_filename] = ( | |
len(script), | |
None, | |
script.splitlines(True), | |
unique_filename, | |
) | |
return locs["__hash__"] | |
def _add_hash(cls, attrs): | |
""" | |
Add a hash method to *cls*. | |
""" | |
cls.__hash__ = _make_hash(attrs) | |
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_cmp(attrs): | |
attrs = [a for a in attrs if a.cmp] | |
# We cache the generated eq methods for the same kinds of attributes. | |
sha1 = hashlib.sha1() | |
sha1.update(repr(attrs).encode("utf-8")) | |
unique_filename = "<attrs generated eq %s>" % (sha1.hexdigest(),) | |
lines = [ | |
"def __eq__(self, other):", | |
" if other.__class__ is not self.__class__:", | |
" return NotImplemented", | |
] | |
# We can't just do a big self.x = other.x and... clause due to | |
# irregularities like nan == nan is false but (nan,) == (nan,) is true. | |
if attrs: | |
lines.append(" return (") | |
others = [ | |
" ) == (", | |
] | |
for a in attrs: | |
lines.append(" self.%s," % (a.name,)) | |
others.append(" other.%s," % (a.name,)) | |
lines += others + [" )"] | |
else: | |
lines.append(" return True") | |
script = "\n".join(lines) | |
globs = {} | |
locs = {} | |
bytecode = compile(script, unique_filename, "exec") | |
eval(bytecode, globs, locs) | |
# In order of debuggers like PDB being able to step through the code, | |
# we add a fake linecache entry. | |
linecache.cache[unique_filename] = ( | |
len(script), | |
None, | |
script.splitlines(True), | |
unique_filename, | |
) | |
eq = locs["__eq__"] | |
ne = _ne | |
def attrs_to_tuple(obj): | |
""" | |
Save us some typing. | |
""" | |
return _attrs_to_tuple(obj, attrs) | |
def lt(self, other): | |
""" | |
Automatically created by attrs. | |
""" | |
if isinstance(other, self.__class__): | |
return attrs_to_tuple(self) < attrs_to_tuple(other) | |
else: | |
return NotImplemented | |
def le(self, other): | |
""" | |
Automatically created by attrs. | |
""" | |
if isinstance(other, self.__class__): | |
return attrs_to_tuple(self) <= attrs_to_tuple(other) | |
else: | |
return NotImplemented | |
def gt(self, other): | |
""" | |
Automatically created by attrs. | |
""" | |
if isinstance(other, self.__class__): | |
return attrs_to_tuple(self) > attrs_to_tuple(other) | |
else: | |
return NotImplemented | |
def ge(self, other): | |
""" | |
Automatically created by attrs. | |
""" | |
if isinstance(other, self.__class__): | |
return attrs_to_tuple(self) >= attrs_to_tuple(other) | |
else: | |
return NotImplemented | |
return eq, ne, lt, le, gt, ge | |
def _add_cmp(cls, attrs=None): | |
""" | |
Add comparison methods to *cls*. | |
""" | |
if attrs is None: | |
attrs = cls.__attrs_attrs__ | |
cls.__eq__, cls.__ne__, cls.__lt__, cls.__le__, cls.__gt__, cls.__ge__ = \ | |
_make_cmp(attrs) | |
return cls | |
def _make_repr(attrs, ns): | |
""" | |
Make a repr method for *attr_names* adding *ns* to the full name. | |
""" | |
attr_names = tuple( | |
a.name | |
for a in attrs | |
if a.repr | |
) | |
def repr_(self): | |
""" | |
Automatically created by attrs. | |
""" | |
real_cls = self.__class__ | |
if ns is None: | |
qualname = getattr(real_cls, "__qualname__", None) | |
if qualname is not None: | |
class_name = qualname.rsplit(">.", 1)[-1] | |
else: | |
class_name = real_cls.__name__ | |
else: | |
class_name = ns + "." + real_cls.__name__ | |
return "{0}({1})".format( | |
class_name, | |
", ".join( | |
name + "=" + repr(getattr(self, name, NOTHING)) | |
for name in attr_names | |
) | |
) | |
return repr_ | |
def _add_repr(cls, ns=None, attrs=None): | |
""" | |
Add a repr method to *cls*. | |
""" | |
if attrs is None: | |
attrs = cls.__attrs_attrs__ | |
repr_ = _make_repr(attrs, ns) | |
cls.__repr__ = repr_ | |
return cls | |
def _make_init(attrs, post_init, frozen): | |
attrs = [ | |
a | |
for a in attrs | |
if a.init or a.default is not NOTHING | |
] | |
# We cache the generated init methods for the same kinds of attributes. | |
sha1 = hashlib.sha1() | |
sha1.update(repr(attrs).encode("utf-8")) | |
unique_filename = "<attrs generated init {0}>".format( | |
sha1.hexdigest() | |
) | |
script, globs = _attrs_to_init_script( | |
attrs, | |
frozen, | |
post_init, | |
) | |
locs = {} | |
bytecode = compile(script, unique_filename, "exec") | |
attr_dict = dict((a.name, a) for a in attrs) | |
globs.update({ | |
"NOTHING": NOTHING, | |
"attr_dict": attr_dict, | |
}) | |
if frozen is True: | |
# Save the lookup overhead in __init__ if we need to circumvent | |
# immutability. | |
globs["_cached_setattr"] = _obj_setattr | |
eval(bytecode, globs, locs) | |
# In order of debuggers like PDB being able to step through the code, | |
# we add a fake linecache entry. | |
linecache.cache[unique_filename] = ( | |
len(script), | |
None, | |
script.splitlines(True), | |
unique_filename, | |
) | |
return locs["__init__"] | |
def _add_init(cls, frozen): | |
""" | |
Add a __init__ method to *cls*. If *frozen* is True, make it immutable. | |
""" | |
cls.__init__ = _make_init( | |
cls.__attrs_attrs__, | |
getattr(cls, "__attrs_post_init__", False), | |
frozen, | |
) | |
return cls | |
def fields(cls): | |
""" | |
Returns the tuple of ``attrs`` attributes for a class. | |
The tuple also allows accessing the fields by their names (see below for | |
examples). | |
:param type cls: Class to introspect. | |
:raise TypeError: If *cls* is not a class. | |
:raise attr.exceptions.NotAnAttrsClassError: If *cls* is not an ``attrs`` | |
class. | |
:rtype: tuple (with name accessors) of :class:`attr.Attribute` | |
.. versionchanged:: 16.2.0 Returned tuple allows accessing the fields | |
by name. | |
""" | |
if not isclass(cls): | |
raise TypeError("Passed object must be a class.") | |
attrs = getattr(cls, "__attrs_attrs__", None) | |
if attrs is None: | |
raise NotAnAttrsClassError( | |
"{cls!r} is not an attrs-decorated class.".format(cls=cls) | |
) | |
return attrs | |
def validate(inst): | |
""" | |
Validate all attributes on *inst* that have a validator. | |
Leaves all exceptions through. | |
:param 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 _attrs_to_init_script(attrs, frozen, post_init): | |
""" | |
Return a script of an initializer for *attrs* and a dict of globals. | |
The globals are expected by the generated script. | |
If *frozen* is True, we cannot set the attributes directly so we use | |
a cached ``object.__setattr__``. | |
""" | |
lines = [] | |
if frozen is True: | |
lines.append( | |
# Circumvent the __setattr__ descriptor to save one lookup per | |
# assignment. | |
"_setattr = _cached_setattr.__get__(self, self.__class__)" | |
) | |
def fmt_setter(attr_name, value_var): | |
return "_setattr('%(attr_name)s', %(value_var)s)" % { | |
"attr_name": attr_name, | |
"value_var": value_var, | |
} | |
def fmt_setter_with_converter(attr_name, value_var): | |
conv_name = _init_convert_pat.format(attr_name) | |
return "_setattr('%(attr_name)s', %(conv)s(%(value_var)s))" % { | |
"attr_name": attr_name, | |
"value_var": value_var, | |
"conv": conv_name, | |
} | |
else: | |
def fmt_setter(attr_name, value): | |
return "self.%(attr_name)s = %(value)s" % { | |
"attr_name": attr_name, | |
"value": value, | |
} | |
def fmt_setter_with_converter(attr_name, value_var): | |
conv_name = _init_convert_pat.format(attr_name) | |
return "self.%(attr_name)s = %(conv)s(%(value_var)s)" % { | |
"attr_name": attr_name, | |
"value_var": value_var, | |
"conv": conv_name, | |
} | |
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 = {} | |
for a in attrs: | |
if a.validator: | |
attrs_to_validate.append(a) | |
attr_name = a.name | |
arg_name = a.name.lstrip("_") | |
has_factory = isinstance(a.default, Factory) | |
if has_factory and a.default.takes_self: | |
maybe_self = "self" | |
else: | |
maybe_self = "" | |
if a.init is False: | |
if has_factory: | |
init_factory_name = _init_factory_pat.format(a.name) | |
if a.convert is not None: | |
lines.append(fmt_setter_with_converter( | |
attr_name, | |
init_factory_name + "({0})".format(maybe_self))) | |
conv_name = _init_convert_pat.format(a.name) | |
names_for_globals[conv_name] = a.convert | |
else: | |
lines.append(fmt_setter( | |
attr_name, | |
init_factory_name + "({0})".format(maybe_self) | |
)) | |
names_for_globals[init_factory_name] = a.default.factory | |
else: | |
if a.convert is not None: | |
lines.append(fmt_setter_with_converter( | |
attr_name, | |
"attr_dict['{attr_name}'].default" | |
.format(attr_name=attr_name) | |
)) | |
conv_name = _init_convert_pat.format(a.name) | |
names_for_globals[conv_name] = a.convert | |
else: | |
lines.append(fmt_setter( | |
attr_name, | |
"attr_dict['{attr_name}'].default" | |
.format(attr_name=attr_name) | |
)) | |
elif a.default is not NOTHING and not has_factory: | |
args.append( | |
"{arg_name}=attr_dict['{attr_name}'].default".format( | |
arg_name=arg_name, | |
attr_name=attr_name, | |
) | |
) | |
if a.convert is not None: | |
lines.append(fmt_setter_with_converter(attr_name, arg_name)) | |
names_for_globals[_init_convert_pat.format(a.name)] = a.convert | |
else: | |
lines.append(fmt_setter(attr_name, arg_name)) | |
elif has_factory: | |
args.append("{arg_name}=NOTHING".format(arg_name=arg_name)) | |
lines.append("if {arg_name} is not NOTHING:" | |
.format(arg_name=arg_name)) | |
init_factory_name = _init_factory_pat.format(a.name) | |
if a.convert is not None: | |
lines.append(" " + fmt_setter_with_converter(attr_name, | |
arg_name)) | |
lines.append("else:") | |
lines.append(" " + fmt_setter_with_converter( | |
attr_name, | |
init_factory_name + "({0})".format(maybe_self) | |
)) | |
names_for_globals[_init_convert_pat.format(a.name)] = a.convert | |
else: | |
lines.append(" " + fmt_setter(attr_name, arg_name)) | |
lines.append("else:") | |
lines.append(" " + fmt_setter( | |
attr_name, | |
init_factory_name + "({0})".format(maybe_self) | |
)) | |
names_for_globals[init_factory_name] = a.default.factory | |
else: | |
args.append(arg_name) | |
if a.convert is not None: | |
lines.append(fmt_setter_with_converter(attr_name, arg_name)) | |
names_for_globals[_init_convert_pat.format(a.name)] = a.convert | |
else: | |
lines.append(fmt_setter(attr_name, arg_name)) | |
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_{}".format(a.name) | |
attr_name = "__attr_{}".format(a.name) | |
lines.append(" {}(self, {}, self.{})".format( | |
val_name, attr_name, a.name)) | |
names_for_globals[val_name] = a.validator | |
names_for_globals[attr_name] = a | |
if post_init: | |
lines.append("self.__attrs_post_init__()") | |
return """\ | |
def __init__(self, {args}): | |
{lines} | |
""".format( | |
args=", ".join(args), | |
lines="\n ".join(lines) if lines else "pass", | |
), names_for_globals | |
class Attribute(object): | |
""" | |
*Read-only* representation of an attribute. | |
:attribute name: The name of the attribute. | |
Plus *all* arguments of :func:`attr.ib`. | |
""" | |
__slots__ = ( | |
"name", "default", "validator", "repr", "cmp", "hash", "init", | |
"convert", "metadata", "type" | |
) | |
def __init__(self, name, default, validator, repr, cmp, hash, init, | |
convert=None, metadata=None, type=None): | |
# Cache this descriptor here to speed things up later. | |
bound_setattr = _obj_setattr.__get__(self, Attribute) | |
bound_setattr("name", name) | |
bound_setattr("default", default) | |
bound_setattr("validator", validator) | |
bound_setattr("repr", repr) | |
bound_setattr("cmp", cmp) | |
bound_setattr("hash", hash) | |
bound_setattr("init", init) | |
bound_setattr("convert", convert) | |
bound_setattr("metadata", (metadata_proxy(metadata) if metadata | |
else _empty_metadata_singleton)) | |
bound_setattr("type", type) | |
def __setattr__(self, name, value): | |
raise FrozenInstanceError() | |
@classmethod | |
def from_counting_attr(cls, name, ca, type=None): | |
# type holds the annotated value. deal with conflicts: | |
if type is None: | |
type = ca.type | |
elif ca.type is not None: | |
raise ValueError( | |
"Type annotation and type argument cannot both be present" | |
) | |
inst_dict = { | |
k: getattr(ca, k) | |
for k | |
in Attribute.__slots__ | |
if k not in ( | |
"name", "validator", "default", "type" | |
) # exclude methods | |
} | |
return cls(name=name, validator=ca._validator, default=ca._default, | |
type=type, **inst_dict) | |
# 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. | |
""" | |
bound_setattr = _obj_setattr.__get__(self, Attribute) | |
for name, value in zip(self.__slots__, state): | |
if name != "metadata": | |
bound_setattr(name, value) | |
else: | |
bound_setattr(name, metadata_proxy(value) if value else | |
_empty_metadata_singleton) | |
_a = [Attribute(name=name, default=NOTHING, validator=None, | |
repr=True, cmp=True, hash=(name != "metadata"), init=True) | |
for name in Attribute.__slots__] | |
Attribute = _add_hash( | |
_add_cmp(_add_repr(Attribute, attrs=_a), attrs=_a), | |
attrs=[a for a in _a if a.hash] | |
) | |
class _CountingAttr(object): | |
""" | |
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__ = ("counter", "_default", "repr", "cmp", "hash", "init", | |
"metadata", "_validator", "convert", "type") | |
__attrs_attrs__ = tuple( | |
Attribute(name=name, default=NOTHING, validator=None, | |
repr=True, cmp=True, hash=True, init=True) | |
for name | |
in ("counter", "_default", "repr", "cmp", "hash", "init",) | |
) + ( | |
Attribute(name="metadata", default=None, validator=None, | |
repr=True, cmp=True, hash=False, init=True), | |
) | |
cls_counter = 0 | |
def __init__(self, default, validator, repr, cmp, hash, init, convert, | |
metadata, type): | |
_CountingAttr.cls_counter += 1 | |
self.counter = _CountingAttr.cls_counter | |
self._default = default | |
# If validator is a list/tuple, wrap it using helper validator. | |
if validator and isinstance(validator, (list, tuple)): | |
self._validator = and_(*validator) | |
else: | |
self._validator = validator | |
self.repr = repr | |
self.cmp = cmp | |
self.hash = hash | |
self.init = init | |
self.convert = convert | |
self.metadata = metadata | |
self.type = type | |
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_cmp(_add_repr(_CountingAttr)) | |
@attrs(slots=True, init=False, hash=True) | |
class Factory(object): | |
""" | |
Stores a factory callable. | |
If passed as the default value to :func:`attr.ib`, the factory is used to | |
generate a new value. | |
:param callable factory: A callable that takes either none or exactly one | |
mandatory positional argument depending on *takes_self*. | |
:param bool takes_self: Pass the partially initialized instance that is | |
being initialized as a positional argument. | |
.. versionadded:: 17.1.0 *takes_self* | |
""" | |
factory = attrib() | |
takes_self = attrib() | |
def __init__(self, factory, takes_self=False): | |
""" | |
`Factory` is part of the default machinery so if we want a default | |
value here, we have to implement it ourselves. | |
""" | |
self.factory = factory | |
self.takes_self = takes_self | |
def make_class(name, attrs, bases=(object,), **attributes_arguments): | |
""" | |
A quick way to create a new class called *name* with *attrs*. | |
:param name: The name for the new class. | |
:type name: str | |
:param attrs: A list of names or a dictionary of mappings of names to | |
attributes. | |
:type attrs: :class:`list` or :class:`dict` | |
:param tuple bases: Classes that the new class will subclass. | |
:param attributes_arguments: Passed unmodified to :func:`attr.s`. | |
:return: A new class with *attrs*. | |
:rtype: type | |
.. versionadded:: 17.1.0 *bases* | |
""" | |
if isinstance(attrs, dict): | |
cls_dict = attrs | |
elif isinstance(attrs, (list, tuple)): | |
cls_dict = dict((a, attrib()) for a in attrs) | |
else: | |
raise TypeError("attrs argument must be a dict or a list.") | |
post_init = cls_dict.pop("__attrs_post_init__", None) | |
type_ = type( | |
name, | |
bases, | |
{} if post_init is None else {"__attrs_post_init__": post_init} | |
) | |
# 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). | |
try: | |
type_.__module__ = sys._getframe(1).f_globals.get( | |
"__name__", "__main__", | |
) | |
except (AttributeError, ValueError): | |
pass | |
return _attrs(these=cls_dict, **attributes_arguments)(type_) | |
# These are required by within this module so we define them here and merely | |
# import into .validators. | |
@attrs(slots=True, hash=True) | |
class _AndValidator(object): | |
""" | |
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. | |
:param validators: Arbitrary number of validators. | |
:type validators: callables | |
.. versionadded:: 17.1.0 | |
""" | |
vals = [] | |
for validator in validators: | |
vals.extend( | |
validator._validators if isinstance(validator, _AndValidator) | |
else [validator] | |
) | |
return _AndValidator(tuple(vals)) |
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