Re: Implementing class methods in C
I think you'd need to write a C++ class that has the methods you want to
implement in C++,
then wrap that with SWIG, then inherit from that, though multiple inheritance
if you also need functions from a base Python class.
The PyQt people use SIP I think, instead of SWIG, might be useful to look into
that too too.
Adriaan.
[EMAIL PROTECTED] 08/18/05 6:42 pm
Nope, it still doesn't work. Anyway, that's not exactly what i want, since
i want func2 to be accessible from all instances of Test()
Naveen
On Thu, 18 Aug 2005, Jeremy Moles wrote:
I honestly don't know the answer to this and I am entirely guessing
but--does it work without using the new module? That is:
import _test
class Foo:
pass
foo = Foo()
foo.bar = _test.func2
foo.bar()
On Thu, 2005-08-18 at 12:09 -0400, [EMAIL PROTECTED] wrote:
I am having a problem implementing some methods of a python class in C.
The class is defined in python, but I would like to rewrite some methods
in c. Here is an example of what I want to do:
file _test.c:
#include Python.h
static PyObject
func2(PyObject *self, PyObject *args)
{
if (self == NULL) {
PyErr_SetString(PyExc_SystemError, self is NULL);
return NULL;
}
// Parse arguments
if (!PyArg_ParseTuple(args, ))
{
return NULL;
}
Py_INCREF(Py_None);
return Py_None;
}
static PyMethodDef TestMethods[] = {
{func2, func2, METH_VARARGS, func2.},
{NULL, NULL, 0, NULL} /* Sentinel */
};
PyMODINIT_FUNC
init_test(void)
{
(void) Py_InitModule(_test, TestMethods);
}
test.py:
class Test:
def func1(self):
print I am in func 1
import _test
import new
Test.func2 = new.instancemethod(_test.func2, None, Test)
del(new)
t = Test()
t.func2()
When I run test.py, I get a SystemError exception (which is what I raise
if self is NULL). I think my confusion lies in the use of PyObject* self
in the function declaration. Shouldn't this be set to point to the
instance of class Test that I am calling it from? Am I misunderstanding
the purpose of PyObject* self? Thanks.
Naveen
-
Naveen Michaud-Agrawal
Program in Molecular Biophysics
Johns Hopkins University
(410) 614 4435
--
http://mail.python.org/mailman/listinfo/python-list
--
http://mail.python.org/mailman/listinfo/python-list
Re: Implementing class methods in C
[EMAIL PROTECTED] wrote: Am I misunderstanding the purpose of PyObject* self? No. I think you do everything right, but it still doesn't work. I have tried to implement it in Python: _test.py: def func2(self, *args): print type(self) print args then all of this works: import _test class Test1: func2 = _test.func2 class Test2: pass Test2.func2 = _test.func2 class Test3: pass import new Test3.func2 = new.instancemethod(_test.func2, None, Test3) del new Test1().func2(1, 2, 3) Test2().func2(1, 2, 3) Test3().func2(1, 2, 3) If you implement _test in C, works none of the above. The only difference I can see is that: type(_test.func2) type 'function' is for Python implemented function and type(_test.func2) type 'builtin_function_or_method' for C implementation I would really like to know the answer too. How do you implement some methods in C without subclassing ? BranoZ -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing class methods in C
If you implement _test in C, works none of the above. The only difference I can see is that: type(_test.func2) type 'function' is for Python implemented function and type(_test.func2) type 'builtin_function_or_method' for C implementation I would really like to know the answer too. How do you implement some methods in C without subclassing ? But the strange thing is if I use new.instancemethod the c function becomes bound (using my previous code for _test.c) import _test class Test: def func1(self): print In class +repr(self.__class__.__namd__) import new Test.func2 = new.instancemethod(_test.func2, None, Test) del new t = Test type(_test.func2) # returns type 'builtin_function_or_method' type(T.func1) # returns unbound method Test.func type(t.func1) # returns bound method Test.func of __main__.Test instance at 0x4eb4b8 type(T.func2) # returns built-in function func2 type(t.func2) # returns bound method Test.func2 of __main__.Test instance at 0x4eb4b8 So is seems like it is bound appropriately, but when called across the C/Python api the first argument (self) of func2 is not separated from the other arguments (and thus is not sent into the c function as PyObject* self, but instead as part of PyObject* args) -- http://mail.python.org/mailman/listinfo/python-list
Implementing class methods in C
I am having a problem implementing some methods of a python class in C.
The class is defined in python, but I would like to rewrite some methods
in c. Here is an example of what I want to do:
file _test.c:
#include Python.h
static PyObject *
func2(PyObject *self, PyObject *args)
{
if (self == NULL) {
PyErr_SetString(PyExc_SystemError, self is NULL);
return NULL;
}
// Parse arguments
if (!PyArg_ParseTuple(args, ))
{
return NULL;
}
Py_INCREF(Py_None);
return Py_None;
}
static PyMethodDef TestMethods[] = {
{func2, func2, METH_VARARGS, func2.},
{NULL, NULL, 0, NULL} /* Sentinel */
};
PyMODINIT_FUNC
init_test(void)
{
(void) Py_InitModule(_test, TestMethods);
}
test.py:
class Test:
def func1(self):
print I am in func 1
import _test
import new
Test.func2 = new.instancemethod(_test.func2, None, Test)
del(new)
t = Test()
t.func2()
When I run test.py, I get a SystemError exception (which is what I raise
if self is NULL). I think my confusion lies in the use of PyObject* self
in the function declaration. Shouldn't this be set to point to the
instance of class Test that I am calling it from? Am I misunderstanding
the purpose of PyObject* self? Thanks.
Naveen
-
Naveen Michaud-Agrawal
Program in Molecular Biophysics
Johns Hopkins University
(410) 614 4435
--
http://mail.python.org/mailman/listinfo/python-list
Re: Implementing class methods in C
I honestly don't know the answer to this and I am entirely guessing
but--does it work without using the new module? That is:
import _test
class Foo:
pass
foo = Foo()
foo.bar = _test.func2
foo.bar()
On Thu, 2005-08-18 at 12:09 -0400, [EMAIL PROTECTED] wrote:
I am having a problem implementing some methods of a python class in C.
The class is defined in python, but I would like to rewrite some methods
in c. Here is an example of what I want to do:
file _test.c:
#include Python.h
static PyObject *
func2(PyObject *self, PyObject *args)
{
if (self == NULL) {
PyErr_SetString(PyExc_SystemError, self is NULL);
return NULL;
}
// Parse arguments
if (!PyArg_ParseTuple(args, ))
{
return NULL;
}
Py_INCREF(Py_None);
return Py_None;
}
static PyMethodDef TestMethods[] = {
{func2, func2, METH_VARARGS, func2.},
{NULL, NULL, 0, NULL} /* Sentinel */
};
PyMODINIT_FUNC
init_test(void)
{
(void) Py_InitModule(_test, TestMethods);
}
test.py:
class Test:
def func1(self):
print I am in func 1
import _test
import new
Test.func2 = new.instancemethod(_test.func2, None, Test)
del(new)
t = Test()
t.func2()
When I run test.py, I get a SystemError exception (which is what I raise
if self is NULL). I think my confusion lies in the use of PyObject* self
in the function declaration. Shouldn't this be set to point to the
instance of class Test that I am calling it from? Am I misunderstanding
the purpose of PyObject* self? Thanks.
Naveen
-
Naveen Michaud-Agrawal
Program in Molecular Biophysics
Johns Hopkins University
(410) 614 4435
--
http://mail.python.org/mailman/listinfo/python-list
Re: Implementing class methods in C
Nope, it still doesn't work. Anyway, that's not exactly what i want, since
i want func2 to be accessible from all instances of Test()
Naveen
On Thu, 18 Aug 2005, Jeremy Moles wrote:
I honestly don't know the answer to this and I am entirely guessing
but--does it work without using the new module? That is:
import _test
class Foo:
pass
foo = Foo()
foo.bar = _test.func2
foo.bar()
On Thu, 2005-08-18 at 12:09 -0400, [EMAIL PROTECTED] wrote:
I am having a problem implementing some methods of a python class in C.
The class is defined in python, but I would like to rewrite some methods
in c. Here is an example of what I want to do:
file _test.c:
#include Python.h
static PyObject *
func2(PyObject *self, PyObject *args)
{
if (self == NULL) {
PyErr_SetString(PyExc_SystemError, self is NULL);
return NULL;
}
// Parse arguments
if (!PyArg_ParseTuple(args, ))
{
return NULL;
}
Py_INCREF(Py_None);
return Py_None;
}
static PyMethodDef TestMethods[] = {
{func2, func2, METH_VARARGS, func2.},
{NULL, NULL, 0, NULL} /* Sentinel */
};
PyMODINIT_FUNC
init_test(void)
{
(void) Py_InitModule(_test, TestMethods);
}
test.py:
class Test:
def func1(self):
print I am in func 1
import _test
import new
Test.func2 = new.instancemethod(_test.func2, None, Test)
del(new)
t = Test()
t.func2()
When I run test.py, I get a SystemError exception (which is what I raise
if self is NULL). I think my confusion lies in the use of PyObject* self
in the function declaration. Shouldn't this be set to point to the
instance of class Test that I am calling it from? Am I misunderstanding
the purpose of PyObject* self? Thanks.
Naveen
-
Naveen Michaud-Agrawal
Program in Molecular Biophysics
Johns Hopkins University
(410) 614 4435
--
http://mail.python.org/mailman/listinfo/python-list
Implementing class methods in C
I am having a problem implementing some methods of a python class in C.
The class is defined in python, but I would like to rewrite some methods
in c. Here is an example of what I want to do:
file _test.c:
#include Python.h
static PyObject *
func2(PyObject *self, PyObject *args)
{
if (self == NULL) {
PyErr_SetString(PyExc_SystemError, self is NULL);
return NULL;
}
// Parse arguments
if (!PyArg_ParseTuple(args, ))
{
return NULL;
}
Py_INCREF(Py_None);
return Py_None;
}
static PyMethodDef TestMethods[] = {
{func2, func2, METH_VARARGS, func2.},
{NULL, NULL, 0, NULL} /* Sentinel */
};
PyMODINIT_FUNC
init_test(void)
{
(void) Py_InitModule(_test, TestMethods);
}
test.py:
class Test:
def func1(self):
print I am in func 1
import _test
import new
Test.func2 = new.instancemethod(_test.func2, None, Test)
del(new)
t = Test()
t.func2()
When I run test.py, I get a SystemError exception (which is what I raise
if self is NULL). I think my confusion lies in the use of PyObject* self
in the function declaration. Shouldn't this be set to point to the
instance of class Test that I am calling it from? Am I misunderstanding
the purpose of PyObject* self? Thanks.
Naveen
-
Naveen Michaud-Agrawal
Program in Molecular Biophysics
Johns Hopkins University
(410) 614 4435
--
http://mail.python.org/mailman/listinfo/python-list
