diff --git a/Doc/library/inspect.rst b/Doc/library/inspect.rst --- a/Doc/library/inspect.rst +++ b/Doc/library/inspect.rst @@ -34,185 +34,190 @@ They also help you determine when you can expect to find the following special attributes: -+-----------+-----------------+---------------------------+ -| Type | Attribute | Description | -+===========+=================+===========================+ -| module | __doc__ | documentation string | -+-----------+-----------------+---------------------------+ -| | __file__ | filename (missing for | -| | | built-in modules) | -+-----------+-----------------+---------------------------+ -| class | __doc__ | documentation string | -+-----------+-----------------+---------------------------+ -| | __name__ | name with which this | -| | | class was defined | -+-----------+-----------------+---------------------------+ -| | __qualname__ | qualified name | -+-----------+-----------------+---------------------------+ -| | __module__ | name of module in which | -| | | this class was defined | -+-----------+-----------------+---------------------------+ -| method | __doc__ | documentation string | -+-----------+-----------------+---------------------------+ -| | __name__ | name with which this | -| | | method was defined | -+-----------+-----------------+---------------------------+ -| | __qualname__ | qualified name | -+-----------+-----------------+---------------------------+ -| | __func__ | function object | -| | | containing implementation | -| | | of method | -+-----------+-----------------+---------------------------+ -| | __self__ | instance to which this | -| | | method is bound, or | -| | | ``None`` | -+-----------+-----------------+---------------------------+ -| function | __doc__ | documentation string | -+-----------+-----------------+---------------------------+ -| | __name__ | name with which this | -| | | function was defined | -+-----------+-----------------+---------------------------+ -| | __qualname__ | qualified name | -+-----------+-----------------+---------------------------+ -| | __code__ | code object containing | -| | | compiled function | -| | | :term:`bytecode` | -+-----------+-----------------+---------------------------+ -| | __defaults__ | tuple of any default | -| | | values for positional or | -| | | keyword parameters | -+-----------+-----------------+---------------------------+ -| | __kwdefaults__ | mapping of any default | -| | | values for keyword-only | -| | | parameters | -+-----------+-----------------+---------------------------+ -| | __globals__ | global namespace in which | -| | | this function was defined | -+-----------+-----------------+---------------------------+ -| | __annotations__ | mapping of parameters | -| | | names to annotations; | -| | | ``"return"`` key is | -| | | reserved for return | -| | | annotations. | -+-----------+-----------------+---------------------------+ -| traceback | tb_frame | frame object at this | -| | | level | -+-----------+-----------------+---------------------------+ -| | tb_lasti | index of last attempted | -| | | instruction in bytecode | -+-----------+-----------------+---------------------------+ -| | tb_lineno | current line number in | -| | | Python source code | -+-----------+-----------------+---------------------------+ -| | tb_next | next inner traceback | -| | | object (called by this | -| | | level) | -+-----------+-----------------+---------------------------+ -| frame | f_back | next outer frame object | -| | | (this frame's caller) | -+-----------+-----------------+---------------------------+ -| | f_builtins | builtins namespace seen | -| | | by this frame | -+-----------+-----------------+---------------------------+ -| | f_code | code object being | -| | | executed in this frame | -+-----------+-----------------+---------------------------+ -| | f_globals | global namespace seen by | -| | | this frame | -+-----------+-----------------+---------------------------+ -| | f_lasti | index of last attempted | -| | | instruction in bytecode | -+-----------+-----------------+---------------------------+ -| | f_lineno | current line number in | -| | | Python source code | -+-----------+-----------------+---------------------------+ -| | f_locals | local namespace seen by | -| | | this frame | -+-----------+-----------------+---------------------------+ -| | f_restricted | 0 or 1 if frame is in | -| | | restricted execution mode | -+-----------+-----------------+---------------------------+ -| | f_trace | tracing function for this | -| | | frame, or ``None`` | -+-----------+-----------------+---------------------------+ -| code | co_argcount | number of arguments (not | -| | | including \* or \*\* | -| | | args) | -+-----------+-----------------+---------------------------+ -| | co_code | string of raw compiled | -| | | bytecode | -+-----------+-----------------+---------------------------+ -| | co_consts | tuple of constants used | -| | | in the bytecode | -+-----------+-----------------+---------------------------+ -| | co_filename | name of file in which | -| | | this code object was | -| | | created | -+-----------+-----------------+---------------------------+ -| | co_firstlineno | number of first line in | -| | | Python source code | -+-----------+-----------------+---------------------------+ -| | co_flags | bitmap: 1=optimized ``|`` | -| | | 2=newlocals ``|`` 4=\*arg | -| | | ``|`` 8=\*\*arg | -+-----------+-----------------+---------------------------+ -| | co_lnotab | encoded mapping of line | -| | | numbers to bytecode | -| | | indices | -+-----------+-----------------+---------------------------+ -| | co_name | name with which this code | -| | | object was defined | -+-----------+-----------------+---------------------------+ -| | co_names | tuple of names of local | -| | | variables | -+-----------+-----------------+---------------------------+ -| | co_nlocals | number of local variables | -+-----------+-----------------+---------------------------+ -| | co_stacksize | virtual machine stack | -| | | space required | -+-----------+-----------------+---------------------------+ -| | co_varnames | tuple of names of | -| | | arguments and local | -| | | variables | -+-----------+-----------------+---------------------------+ -| generator | __name__ | name | -+-----------+-----------------+---------------------------+ -| | __qualname__ | qualified name | -+-----------+-----------------+---------------------------+ -| | gi_frame | frame | -+-----------+-----------------+---------------------------+ -| | gi_running | is the generator running? | -+-----------+-----------------+---------------------------+ -| | gi_code | code | -+-----------+-----------------+---------------------------+ -| | gi_yieldfrom | object being iterated by | -| | | ``yield from``, or | -| | | ``None`` | -+-----------+-----------------+---------------------------+ -| coroutine | __name__ | name | -+-----------+-----------------+---------------------------+ -| | __qualname__ | qualified name | -+-----------+-----------------+---------------------------+ -| | cr_await | object being awaited on, | -| | | or ``None`` | -+-----------+-----------------+---------------------------+ -| | cr_frame | frame | -+-----------+-----------------+---------------------------+ -| | cr_running | is the coroutine running? | -+-----------+-----------------+---------------------------+ -| | cr_code | code | -+-----------+-----------------+---------------------------+ -| builtin | __doc__ | documentation string | -+-----------+-----------------+---------------------------+ -| | __name__ | original name of this | -| | | function or method | -+-----------+-----------------+---------------------------+ -| | __qualname__ | qualified name | -+-----------+-----------------+---------------------------+ -| | __self__ | instance to which a | -| | | method is bound, or | -| | | ``None`` | -+-----------+-----------------+---------------------------+ ++-----------+----------------------+---------------------------+ +| Type | Attribute | Description | ++===========+======================+===========================+ +| module | __doc__ | documentation string | ++-----------+----------------------+---------------------------+ +| | __file__ | filename (missing for | +| | | built-in modules) | ++-----------+----------------------+---------------------------+ +| class | __doc__ | documentation string | ++-----------+----------------------+---------------------------+ +| | __name__ | name with which this | +| | | class was defined | ++-----------+----------------------+---------------------------+ +| | __qualname__ | qualified name | ++-----------+----------------------+---------------------------+ +| | __module__ | name of module in which | +| | | this class was defined | ++-----------+----------------------+---------------------------+ +| | __definition_order__ | the names of the class's | +| | | attributes, in the order | +| | | in which they were | +| | | defined (if known) | ++-----------+----------------------+---------------------------+ +| method | __doc__ | documentation string | ++-----------+----------------------+---------------------------+ +| | __name__ | name with which this | +| | | method was defined | ++-----------+----------------------+---------------------------+ +| | __qualname__ | qualified name | ++-----------+----------------------+---------------------------+ +| | __func__ | function object | +| | | containing implementation | +| | | of method | ++-----------+----------------------+---------------------------+ +| | __self__ | instance to which this | +| | | method is bound, or | +| | | ``None`` | ++-----------+----------------------+---------------------------+ +| function | __doc__ | documentation string | ++-----------+----------------------+---------------------------+ +| | __name__ | name with which this | +| | | function was defined | ++-----------+----------------------+---------------------------+ +| | __qualname__ | qualified name | ++-----------+----------------------+---------------------------+ +| | __code__ | code object containing | +| | | compiled function | +| | | :term:`bytecode` | ++-----------+----------------------+---------------------------+ +| | __defaults__ | tuple of any default | +| | | values for positional or | +| | | keyword parameters | ++-----------+----------------------+---------------------------+ +| | __kwdefaults__ | mapping of any default | +| | | values for keyword-only | +| | | parameters | ++-----------+----------------------+---------------------------+ +| | __globals__ | global namespace in which | +| | | this function was defined | ++-----------+----------------------+---------------------------+ +| | __annotations__ | mapping of parameters | +| | | names to annotations; | +| | | ``"return"`` key is | +| | | reserved for return | +| | | annotations. | ++-----------+----------------------+---------------------------+ +| traceback | tb_frame | frame object at this | +| | | level | ++-----------+----------------------+---------------------------+ +| | tb_lasti | index of last attempted | +| | | instruction in bytecode | ++-----------+----------------------+---------------------------+ +| | tb_lineno | current line number in | +| | | Python source code | ++-----------+----------------------+---------------------------+ +| | tb_next | next inner traceback | +| | | object (called by this | +| | | level) | ++-----------+----------------------+---------------------------+ +| frame | f_back | next outer frame object | +| | | (this frame's caller) | ++-----------+----------------------+---------------------------+ +| | f_builtins | builtins namespace seen | +| | | by this frame | ++-----------+----------------------+---------------------------+ +| | f_code | code object being | +| | | executed in this frame | ++-----------+----------------------+---------------------------+ +| | f_globals | global namespace seen by | +| | | this frame | ++-----------+----------------------+---------------------------+ +| | f_lasti | index of last attempted | +| | | instruction in bytecode | ++-----------+----------------------+---------------------------+ +| | f_lineno | current line number in | +| | | Python source code | ++-----------+----------------------+---------------------------+ +| | f_locals | local namespace seen by | +| | | this frame | ++-----------+----------------------+---------------------------+ +| | f_restricted | 0 or 1 if frame is in | +| | | restricted execution mode | ++-----------+----------------------+---------------------------+ +| | f_trace | tracing function for this | +| | | frame, or ``None`` | ++-----------+----------------------+---------------------------+ +| code | co_argcount | number of arguments (not | +| | | including \* or \*\* | +| | | args) | ++-----------+----------------------+---------------------------+ +| | co_code | string of raw compiled | +| | | bytecode | ++-----------+----------------------+---------------------------+ +| | co_consts | tuple of constants used | +| | | in the bytecode | ++-----------+----------------------+---------------------------+ +| | co_filename | name of file in which | +| | | this code object was | +| | | created | ++-----------+----------------------+---------------------------+ +| | co_firstlineno | number of first line in | +| | | Python source code | ++-----------+----------------------+---------------------------+ +| | co_flags | bitmap: 1=optimized ``|`` | +| | | 2=newlocals ``|`` 4=\*arg | +| | | ``|`` 8=\*\*arg | ++-----------+----------------------+---------------------------+ +| | co_lnotab | encoded mapping of line | +| | | numbers to bytecode | +| | | indices | ++-----------+----------------------+---------------------------+ +| | co_name | name with which this code | +| | | object was defined | ++-----------+----------------------+---------------------------+ +| | co_names | tuple of names of local | +| | | variables | ++-----------+----------------------+---------------------------+ +| | co_nlocals | number of local variables | ++-----------+----------------------+---------------------------+ +| | co_stacksize | virtual machine stack | +| | | space required | ++-----------+----------------------+---------------------------+ +| | co_varnames | tuple of names of | +| | | arguments and local | +| | | variables | ++-----------+----------------------+---------------------------+ +| generator | __name__ | name | ++-----------+----------------------+---------------------------+ +| | __qualname__ | qualified name | ++-----------+----------------------+---------------------------+ +| | gi_frame | frame | ++-----------+----------------------+---------------------------+ +| | gi_running | is the generator running? | ++-----------+----------------------+---------------------------+ +| | gi_code | code | ++-----------+----------------------+---------------------------+ +| | gi_yieldfrom | object being iterated by | +| | | ``yield from``, or | +| | | ``None`` | ++-----------+----------------------+---------------------------+ +| coroutine | __name__ | name | ++-----------+----------------------+---------------------------+ +| | __qualname__ | qualified name | ++-----------+----------------------+---------------------------+ +| | cr_await | object being awaited on, | +| | | or ``None`` | ++-----------+----------------------+---------------------------+ +| | cr_frame | frame | ++-----------+----------------------+---------------------------+ +| | cr_running | is the coroutine running? | ++-----------+----------------------+---------------------------+ +| | cr_code | code | ++-----------+----------------------+---------------------------+ +| builtin | __doc__ | documentation string | ++-----------+----------------------+---------------------------+ +| | __name__ | original name of this | +| | | function or method | ++-----------+----------------------+---------------------------+ +| | __qualname__ | qualified name | ++-----------+----------------------+---------------------------+ +| | __self__ | instance to which a | +| | | method is bound, or | +| | | ``None`` | ++-----------+----------------------+---------------------------+ .. versionchanged:: 3.5 @@ -221,6 +226,10 @@ The ``__name__`` attribute of generators is now set from the function name, instead of the code name, and it can now be modified. +.. versionchanged:: 3.6 + + Add ``__definition_order__`` to classes. + .. function:: getmembers(object[, predicate]) diff --git a/Doc/library/types.rst b/Doc/library/types.rst --- a/Doc/library/types.rst +++ b/Doc/library/types.rst @@ -53,8 +53,20 @@ in *kwds* argument with any ``'metaclass'`` entry removed. If no *kwds* argument is passed in, this will be an empty dict. + .. impl-detail:: + + CPython uses :class:`collections.OrderedDict` for the default + namespace. + .. versionadded:: 3.3 + .. versionchanged:: 3.6 + + The default value for the ``namespace`` element of the returned + tuple has changed from :func:`dict`. Now an insertion-order- + preserving mapping is used when the metaclass does not have a + ``__prepare__`` attribute, + .. seealso:: :ref:`metaclasses` diff --git a/Doc/reference/compound_stmts.rst b/Doc/reference/compound_stmts.rst --- a/Doc/reference/compound_stmts.rst +++ b/Doc/reference/compound_stmts.rst @@ -630,6 +630,17 @@ dictionary. The class name is bound to this class object in the original local namespace. +The order in which attributes are defined in the class body is preserved +in the ``__definition_order__`` attribute on the new class. If that order +is not known then the attribute is set to :const:`None`. The class body +may include a ``__definition_order__`` attribute. In that case it is used +directly. The value must be a tuple of identifiers or ``None``, otherwise +:exc:`TypeError` will be raised when the class statement is executed. + +.. versionchanged:: 3.6 + + Add ``__definition_order__`` to classes. + Class creation can be customized heavily using :ref:`metaclasses `. Classes can also be decorated: just like when decorating functions, :: diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst --- a/Doc/reference/datamodel.rst +++ b/Doc/reference/datamodel.rst @@ -1691,7 +1691,14 @@ additional keyword arguments, if any, come from the class definition). If the metaclass has no ``__prepare__`` attribute, then the class namespace -is initialised as an empty :func:`dict` instance. +is initialised as an empty ordered mapping. + +.. impl-detail:: + + In CPython the default is :class:`collections.OrderedDict`. + +.. versionchanged:: 3.6 + Defaults to :class:`collections.OrderedDict` instead of :func:`dict`. .. seealso:: diff --git a/Doc/whatsnew/3.6.rst b/Doc/whatsnew/3.6.rst --- a/Doc/whatsnew/3.6.rst +++ b/Doc/whatsnew/3.6.rst @@ -88,6 +88,7 @@ :pep:`4XX` - Python Virtual Environments PEP written by Carl Meyer +.. XXX PEP 520: :ref:`Preserving Class Attribute Definition Order` New Features ============ @@ -184,6 +185,26 @@ (Contributed by Victor Stinner in :issue:`26516` and :issue:`26564`.) +.. _whatsnew-deforder: + +PEP 520: Preserving Class Attribute Definition Order +---------------------------------------------------- + +Attributes in a class definition body have a natural ordering: the same +order in which the names appear in the source. This order is now +preserved in the new class's ``__definition_order__`` attribute. It is +a tuple of the attribute names, in the order in which they appear in +the class definition body. + +For types that don't have a definition (e.g. builtins), or the attribute +order could not be determined, ``__definition_order__`` is ``None``. + +Also, the effective default class *execution* namespace (returned from +``type.__prepare__()``) is now an insertion-order-preserving mapping. +For CPython, it is now ``collections.OrderedDict``. Note that the +class namespace, ``cls.__dict__``, is unchanged. + + Other Language Changes ====================== diff --git a/Include/object.h b/Include/object.h --- a/Include/object.h +++ b/Include/object.h @@ -421,6 +421,8 @@ destructor tp_finalize; + PyObject *tp_deforder; + #ifdef COUNT_ALLOCS /* these must be last and never explicitly initialized */ Py_ssize_t tp_allocs; diff --git a/Include/odictobject.h b/Include/odictobject.h --- a/Include/odictobject.h +++ b/Include/odictobject.h @@ -28,6 +28,10 @@ PyAPI_FUNC(int) PyODict_SetItem(PyObject *od, PyObject *key, PyObject *item); PyAPI_FUNC(int) PyODict_DelItem(PyObject *od, PyObject *key); +#ifndef Py_LIMITED_API +PyAPI_FUNC(PyObject *) _PyODict_KeysAsTuple(PyObject *od); +#endif + /* wrappers around PyDict* functions */ #define PyODict_GetItem(od, key) PyDict_GetItem((PyObject *)od, key) #define PyODict_GetItemWithError(od, key) \ diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py --- a/Lib/test/test_builtin.py +++ b/Lib/test/test_builtin.py @@ -14,8 +14,10 @@ import types import unittest import warnings +from collections import OrderedDict from operator import neg -from test.support import TESTFN, unlink, run_unittest, check_warnings +from test.support import (TESTFN, unlink, run_unittest, check_warnings, + cpython_only) from test.support.script_helper import assert_python_ok try: import pty, signal @@ -1777,6 +1779,146 @@ A.__doc__ = doc self.assertEqual(A.__doc__, doc) + def test_type_definition_order(self): + class Spam: + b = 1 + c = 3 + a = 2 + d = 4 + eggs = 2 + e = 5 + b = 42 + + self.assertEqual(Spam.__definition_order__, + ('__module__', '__qualname__', + 'b', 'c', 'a', 'd', 'eggs', 'e')) + with self.assertRaises(AttributeError): + Spam().__definition_order__ + Spam.__definition_order__ = None + self.assertEqual(Spam.__definition_order__, None) + Spam.__definition_order__ = ('x', 'y', 'z') + self.assertEqual(Spam.__definition_order__, ('x', 'y', 'z')) + del Spam.__definition_order__ + self.assertEqual(Spam.__definition_order__, None) + Spam.__definition_order__ = 42 + self.assertEqual(Spam.__definition_order__, 42) + + self.assertEqual(object.__definition_order__, None) + self.assertEqual(type.__definition_order__, None) + self.assertEqual(dict.__definition_order__, None) + self.assertEqual(type(None).__definition_order__, None) + + class Empty: + pass + + self.assertEqual(Empty.__definition_order__, + ('__module__', '__qualname__')) + + class Dunder: + VAR = 3 + def __init__(self): + pass + + self.assertEqual(Dunder.__definition_order__, + ('__module__', '__qualname__', + 'VAR', '__init__')) + + class DunderOnly: + __xyz__ = None + def __init__(self): + pass + + self.assertEqual(DunderOnly.__definition_order__, + ('__module__', '__qualname__', + '__xyz__', '__init__')) + + class HalfDunder: + __whether_to_be = True + or_not_to_be__ = False + + self.assertEqual(HalfDunder.__definition_order__, + ('__module__', '__qualname__', + '_HalfDunder__whether_to_be', 'or_not_to_be__')) + + class Slots: + __slots__ = ('x', 'y') + a = 1 + b = 2 + + self.assertEqual(Slots.__definition_order__, + ('__module__', '__qualname__', + '__slots__', 'a', 'b')) + + class OverwrittenNone: + __definition_order__ = None + a = 1 + b = 2 + c = 3 + + self.assertEqual(OverwrittenNone.__definition_order__, None) + + class OverwrittenTuple: + __definition_order__ = ('x', 'y', 'z') + a = 1 + b = 2 + c = 3 + + self.assertEqual(OverwrittenTuple.__definition_order__, + ('x', 'y', 'z')) + + with self.assertRaises(TypeError): + class PoorlyOverwritten: + __definition_order__ = ('a', 2, 'c') + a = 1 + b = 2 + c = 3 + + class Meta(type): + SPAM = 42 + + def __init__(self, *args, **kwargs): + super().__init__(*args, **kwargs) + + self.assertEqual(Meta.__definition_order__, + ('__module__', '__qualname__', + 'SPAM', '__init__')) + + def test_type_definition_order_OrderedDict(self): + class Meta(type): + def __prepare__(self, *args, **kwargs): + return OrderedDict() + + class WithODict(metaclass=Meta): + x='y' + + self.assertEqual(WithODict.__definition_order__, + ('__module__', '__qualname__', 'x')) + + class Meta(type): + def __prepare__(self, *args, **kwargs): + class ODictSub(OrderedDict): + pass + return ODictSub() + + class WithODictSub(metaclass=Meta): + x='y' + + self.assertEqual(WithODictSub.__definition_order__, + ('__module__', '__qualname__', 'x')) + + @cpython_only + def test_type_definition_order_cpython(self): + # some implementations will have an ordered-by-default dict. + + class Meta(type): + def __prepare__(self, *args, **kwargs): + return {} + + class NotOrdered(metaclass=Meta): + x='y' + + self.assertEqual(NotOrdered.__definition_order__, None) + def test_bad_args(self): with self.assertRaises(TypeError): type() diff --git a/Lib/test/test_metaclass.py b/Lib/test/test_metaclass.py --- a/Lib/test/test_metaclass.py +++ b/Lib/test/test_metaclass.py @@ -180,7 +180,7 @@ meta: C () ns: [('__module__', 'test.test_metaclass'), ('__qualname__', 'C'), ('a', 42), ('b', 24)] kw: [] - >>> type(C) is dict + >>> type(C) is types._DefaultClassNamespaceType True >>> print(sorted(C.items())) [('__module__', 'test.test_metaclass'), ('__qualname__', 'C'), ('a', 42), ('b', 24)] @@ -211,8 +211,11 @@ The default metaclass must define a __prepare__() method. - >>> type.__prepare__() - {} + >>> ns = type.__prepare__() + >>> type(ns) is types._DefaultClassNamespaceType + True + >>> list(ns) == [] + True >>> Make sure it works with subclassing. @@ -248,7 +251,9 @@ """ +from collections import OrderedDict import sys +import types # Trace function introduces __locals__ which causes various tests to fail. if hasattr(sys, 'gettrace') and sys.gettrace(): diff --git a/Lib/test/test_pydoc.py b/Lib/test/test_pydoc.py --- a/Lib/test/test_pydoc.py +++ b/Lib/test/test_pydoc.py @@ -427,6 +427,7 @@ expected_html = expected_html_pattern % ( (mod_url, mod_file, doc_loc) + expected_html_data_docstrings) + self.maxDiff = None self.assertEqual(result, expected_html) @unittest.skipIf(sys.flags.optimize >= 2, @@ -473,13 +474,18 @@ def test_non_str_name(self): # issue14638 # Treat illegal (non-str) name like no name + # Definition order is set to None so it looks the same in both + # cases. class A: + __definition_order__ = None __name__ = 42 class B: pass adoc = pydoc.render_doc(A()) bdoc = pydoc.render_doc(B()) - self.assertEqual(adoc.replace("A", "B"), bdoc) + self.maxDiff = None + expected = adoc.replace("A", "B") + self.assertEqual(bdoc, expected) def test_not_here(self): missing_module = "test.i_am_not_here" diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py --- a/Lib/test/test_sys.py +++ b/Lib/test/test_sys.py @@ -1084,7 +1084,7 @@ check((1,2,3), vsize('') + 3*self.P) # type # static type: PyTypeObject - fmt = 'P2n15Pl4Pn9Pn11PIP' + fmt = 'P2n15Pl4Pn9Pn11PIPP' if hasattr(sys, 'getcounts'): fmt += '3n2P' s = vsize(fmt) diff --git a/Lib/test/test_types.py b/Lib/test/test_types.py --- a/Lib/test/test_types.py +++ b/Lib/test/test_types.py @@ -825,6 +825,28 @@ self.assertEqual(C.y, 1) self.assertEqual(C.z, 2) + def test_new_class_deforder(self): + C = types.new_class("C") + self.assertEqual(C.__definition_order__, tuple()) + + Meta = self.Meta + def func(ns): + ns["x"] = 0 + D = types.new_class("D", (), {"metaclass": Meta, "z": 2}, func) + self.assertEqual(D.__definition_order__, ('y', 'z', 'x')) + + def func(ns): + ns["__definition_order__"] = None + ns["x"] = 0 + D = types.new_class("D", (), {"metaclass": Meta, "z": 2}, func) + self.assertEqual(D.__definition_order__, None) + + def func(ns): + ns["__definition_order__"] = ('a', 'b', 'c') + ns["x"] = 0 + D = types.new_class("D", (), {"metaclass": Meta, "z": 2}, func) + self.assertEqual(D.__definition_order__, ('a', 'b', 'c')) + # Many of the following tests are derived from test_descr.py def test_prepare_class(self): # Basic test of metaclass derivation diff --git a/Lib/types.py b/Lib/types.py --- a/Lib/types.py +++ b/Lib/types.py @@ -25,8 +25,11 @@ _c.close() # Prevent ResourceWarning class _C: + _nsType = type(locals()) def _m(self): pass MethodType = type(_C()._m) +# In CPython, this should end up as OrderedDict. +_DefaultClassNamespaceType = _C._nsType BuiltinFunctionType = type(len) BuiltinMethodType = type([].append) # Same as BuiltinFunctionType @@ -85,7 +88,7 @@ if hasattr(meta, '__prepare__'): ns = meta.__prepare__(name, bases, **kwds) else: - ns = {} + ns = _DefaultClassNamespaceType() return meta, ns, kwds def _calculate_meta(meta, bases): diff --git a/Lib/typing.py b/Lib/typing.py --- a/Lib/typing.py +++ b/Lib/typing.py @@ -1305,6 +1305,7 @@ if (not attr.startswith('_abc_') and attr != '__abstractmethods__' and attr != '_is_protocol' and + attr != '__definition_order__' and attr != '__dict__' and attr != '__args__' and attr != '__slots__' and diff --git a/Objects/odictobject.c b/Objects/odictobject.c --- a/Objects/odictobject.c +++ b/Objects/odictobject.c @@ -1762,6 +1762,21 @@ return _PyDict_DelItem_KnownHash(od, key, hash); } +PyObject * +_PyODict_KeysAsTuple(PyObject *od) { + Py_ssize_t i = 0; + _ODictNode *node; + PyObject *keys = PyTuple_New(PyODict_Size(od)); + if (keys == NULL) + return NULL; + _odict_FOREACH((PyODictObject *)od, node) { + Py_INCREF(_odictnode_KEY(node)); + PyTuple_SET_ITEM(keys, i, _odictnode_KEY(node)); + i++; + } + return keys; +} + /* ------------------------------------------- * The OrderedDict views (keys/values/items) diff --git a/Objects/typeobject.c b/Objects/typeobject.c --- a/Objects/typeobject.c +++ b/Objects/typeobject.c @@ -48,6 +48,7 @@ _Py_IDENTIFIER(__abstractmethods__); _Py_IDENTIFIER(__class__); _Py_IDENTIFIER(__delitem__); +_Py_IDENTIFIER(__definition_order__); _Py_IDENTIFIER(__dict__); _Py_IDENTIFIER(__doc__); _Py_IDENTIFIER(__getattribute__); @@ -487,6 +488,23 @@ } static PyObject * +type_deforder(PyTypeObject *type, void *context) +{ + if (type->tp_deforder == NULL) + Py_RETURN_NONE; + Py_INCREF(type->tp_deforder); + return type->tp_deforder; +} + +static int +type_set_deforder(PyTypeObject *type, PyObject *value, void *context) +{ + Py_XINCREF(value); + Py_XSETREF(type->tp_deforder, value); + return 0; +} + +static PyObject * type_abstractmethods(PyTypeObject *type, void *context) { PyObject *mod = NULL; @@ -832,6 +850,8 @@ {"__qualname__", (getter)type_qualname, (setter)type_set_qualname, NULL}, {"__bases__", (getter)type_get_bases, (setter)type_set_bases, NULL}, {"__module__", (getter)type_module, (setter)type_set_module, NULL}, + {"__definition_order__", (getter)type_deforder, + (setter)type_set_deforder, NULL}, {"__abstractmethods__", (getter)type_abstractmethods, (setter)type_set_abstractmethods, NULL}, {"__dict__", (getter)type_dict, NULL, NULL}, @@ -2339,6 +2359,7 @@ goto error; } + /* Copy the definition namespace into a new dict. */ dict = PyDict_Copy(orig_dict); if (dict == NULL) goto error; @@ -2547,6 +2568,48 @@ if (qualname != NULL && PyDict_DelItem(dict, PyId___qualname__.object) < 0) goto error; + /* Set tp_deforder to the extracted definition order, if any. */ + type->tp_deforder = _PyDict_GetItemId(dict, &PyId___definition_order__); + if (type->tp_deforder != NULL) { + Py_INCREF(type->tp_deforder); + + // Due to subclass lookup, __definition_order__ can't be in __dict__. + if (_PyDict_DelItemId(dict, &PyId___definition_order__) != 0) { + goto error; + } + + if (type->tp_deforder != Py_None) { + Py_ssize_t numnames; + + if (!PyTuple_Check(type->tp_deforder)) { + PyErr_SetString(PyExc_TypeError, + "__definition_order__ must be a tuple or None"); + goto error; + } + + // Make sure they are identifers. + numnames = PyTuple_Size(type->tp_deforder); + for (i = 0; i < numnames; i++) { + PyObject *name = PyTuple_GET_ITEM(type->tp_deforder, i); + if (name == NULL) { + goto error; + } + if (!PyUnicode_Check(name) || !PyUnicode_IsIdentifier(name)) { + PyErr_Format(PyExc_TypeError, + "__definition_order__ must " + "contain only identifiers, got '%s'", + name); + goto error; + } + } + } + } + else if (PyODict_Check(orig_dict)) { + type->tp_deforder = _PyODict_KeysAsTuple(orig_dict); + if (type->tp_deforder == NULL) + goto error; + } + /* Set tp_doc to a copy of dict['__doc__'], if the latter is there and is a string. The __doc__ accessor will first look for tp_doc; if that fails, it will still look into __dict__. @@ -3041,6 +3104,7 @@ Py_XDECREF(type->tp_mro); Py_XDECREF(type->tp_cache); Py_XDECREF(type->tp_subclasses); + Py_XDECREF(type->tp_deforder); /* A type's tp_doc is heap allocated, unlike the tp_doc slots * of most other objects. It's okay to cast it to char *. */ @@ -3083,7 +3147,7 @@ static PyObject * type_prepare(PyObject *self, PyObject *args, PyObject *kwds) { - return PyDict_New(); + return PyODict_New(); } /* diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c --- a/Python/bltinmodule.c +++ b/Python/bltinmodule.c @@ -145,7 +145,7 @@ if (prep == NULL) { if (PyErr_ExceptionMatches(PyExc_AttributeError)) { PyErr_Clear(); - ns = PyDict_New(); + ns = PyODict_New(); } else { Py_DECREF(meta);