Hello!
I'm writing a wrapper for C-library. When something goes wrong in that library, i can get error details. And i want to assign them to fields of my own exception class.
For this purpose, i looked throught Modules/_ctypes/_ctypes.c
(in python source tree) and implemented same things. Briefly:
- define
PyObject * Error
in header file, - write init and other necessary functions
- assign them to
PyMethodDef
array - initialize class's dict with methods above (in function
create_error
) - create new exception with no base class and with dict (in function
create_error
) - call to
create_error
and assignError
class to module (PyModule_AddObject
) - throw error with
PyErr_SetObject(Error, tpl);
, wheretpl
is tuple with error details, which are assigned to Error's fields in init function
All of this is consistent with what i saw in Modules/_ctypes/_ctypes.c
, i think. But it doesn't work:
when i call PyErr_SetObject(Error, tpl);
, Python's runtime raises error:
TypeError: unbound method __init__() must be called with Error instance as first argument (got str instance instead)
And PyObject_Print(Error, stdout, 0);
returns:
{'__init__': <unbound method Error.__init__> ...}
It's item for init function in PyMethodDef
array:
{"__init__", myerror_init, METH_VARARGS, "initialize error"}
and it's function's signature:
static PyObject * myerror_init(PyObject * self, PyObject *args)
(python version -- 2.6.4)
Why methods are unbound? And what i've missed? Or what is the right and pythonic way to define exception with custom class attributes?
Thanks.