[Python-Dev] python 3.0, tp_compare not used for == test?
Campbell Barton
ideasman42 at gmail.com
Mon Feb 2 06:12:37 CET 2009
Hi, I have been writing a new C api that can build with both python 2.6 and 3.0
I found that when building with python 2.6, doing "a==b" between 2
different pyrna_struct_Type's would run tp_compare
But with python 3.0, "a==b" will always be false and tp_compare
function would not even run.
The only way to get it to run the tp_compare function was to do
"cmp(a, b)" however Id like to be able to use == still.
The only way I could get "a==b" to work in python 3.0 was to add a
tp_richcompare function which runs tp_compare with Py_CmpToRich()
anyway
Is this the intended behavior? - if so its important for external C
API's to be updated to support this.
Included the PyType below with some relevant details. I looked at
other Python 3.0 types but could not see why this would happen.
// ----snip,
// initialized with PyType_Ready
if( PyType_Ready( &pyrna_struct_Type ) < 0 )
return NULL;
// header definition for BPy_StructRNA
typedef struct {
PyObject_HEAD /* required python macro */
PointerRNA ptr;
int freeptr; /* needed in some cases if ptr.data is created on the
fly, free when deallocing */
} BPy_StructRNA;
// PyType
/*-----------------------BPy_StructRNA method
def------------------------------*/
PyTypeObject pyrna_struct_Type = {
PyVarObject_HEAD_INIT(NULL, 0)
"StructRNA", /* tp_name */
sizeof( BPy_StructRNA ), /* tp_basicsize */
0, /* tp_itemsize */
/* methods */
( destructor ) pyrna_struct_dealloc,/* tp_dealloc */
NULL, /* printfunc tp_print; */
NULL, /* getattrfunc tp_getattr; */
NULL, /* setattrfunc tp_setattr; */
( cmpfunc ) pyrna_struct_compare, /* tp_compare */
( reprfunc ) pyrna_struct_repr, /* tp_repr */
/* Method suites for standard classes */
NULL, /* PyNumberMethods *tp_as_number; */
NULL, /* PySequenceMethods *tp_as_sequence; */
NULL, /* PyMappingMethods *tp_as_mapping; */
/* More standard operations (here for binary compatibility) */
( hashfunc )pyrna_struct_hash, /* hashfunc tp_hash; */
NULL, /* ternaryfunc tp_call; */
NULL, /* reprfunc tp_str; */
( getattrofunc ) pyrna_struct_getattro, /* getattrofunc tp_getattro; */
( setattrofunc ) pyrna_struct_setattro, /* setattrofunc tp_setattro; */
/* Functions to access object as input/output buffer */
NULL, /* PyBufferProcs *tp_as_buffer; */
/*** Flags to define presence of optional/expanded features ***/
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* long tp_flags; */
NULL, /* char *tp_doc; Documentation string */
/*** Assigned meaning in release 2.0 ***/
/* call function for all accessible objects */
NULL, /* traverseproc tp_traverse; */
/* delete references to contained objects */
NULL, /* inquiry tp_clear; */
/*** Assigned meaning in release 2.1 ***/
/*** rich comparisons ***/
(richcmpfunc)pyrna_struct_richcmp, /* richcmpfunc tp_richcompare; */
/*** weak reference enabler ***/
0, /* long tp_weaklistoffset; */
/*** Added in release 2.2 ***/
/* Iterators */
NULL, /* getiterfunc tp_iter; */
NULL, /* iternextfunc tp_iternext; */
/*** Attribute descriptor and subclassing stuff ***/
pyrna_struct_methods, /* struct PyMethodDef *tp_methods; */
NULL, /* struct PyMemberDef *tp_members; */
NULL, /* struct PyGetSetDef *tp_getset; */
NULL, /* struct _typeobject *tp_base; */
NULL, /* PyObject *tp_dict; */
NULL, /* descrgetfunc tp_descr_get; */
NULL, /* descrsetfunc tp_descr_set; */
0, /* long tp_dictoffset; */
NULL, /* initproc tp_init; */
NULL, /* allocfunc tp_alloc; */
pyrna_struct_new, /* newfunc tp_new; */
/* Low-level free-memory routine */
NULL, /* freefunc tp_free; */
/* For PyObject_IS_GC */
NULL, /* inquiry tp_is_gc; */
NULL, /* PyObject *tp_bases; */
/* method resolution order */
NULL, /* PyObject *tp_mro; */
NULL, /* PyObject *tp_cache; */
NULL, /* PyObject *tp_subclasses; */
NULL, /* PyObject *tp_weaklist; */
NULL
};
--
- Campbell
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