Python 2.3.4 (#1, May 29 2004, 17:05:23)
[GCC 3.3.3] on linux2
Getting some strange behaviour with keyword arguments for optional
arguments in extension modules. See the simple test case below
--------8<--------------------------------------------------
#include "Python.h"
static PyObject *
keywdarg_test(PyObject *self, PyObject *args, PyObject *keywds)
{
int one;
unsigned int two = 2;
int three = 3;
static char *kwlist[] = {"one", "two", "three", NULL};
if (!PyArg_ParseTupleAndKeywords(args, keywds, "i|Ii", kwlist,
&one, &two, &three))
return NULL;
Py_INCREF(Py_None);
return Py_None;
}
static PyMethodDef keywdarg_methods[] = {
{"test", (PyCFunction)keywdarg_test, METH_VARARGS | METH_KEYWORDS},
{NULL, NULL, 0, NULL}
};
void
initkeywdarg(void)
{
Py_InitModule("keywdarg", keywdarg_methods);
}
--------8<--------------------------------------------------
Compile the module
$ cc -g -c keywdarg.c -I/usr/include/python2.3
$ ld -shared -o keywdarg.so keywdarg.o
Test it
In [1]: from keywdarg import *
In [2]: test(1)
In [3]: test(1,two=2)
In [4]: test(1,two=2,three=3)
In [5]: test(1,three=3,two=2)
In [6]: test(1,three=3)
---------------------------------------------------------------------------
exceptions.TypeError Traceback (most recent
call last)
/home/sean/research/code/framework/wiener/<console>
TypeError: argument 2, item 1074941247, item 1079307903 impossible<bad format
char>
However if I change the order of the optional arguments so the unsigned
int is last as below then it works fine.
if (!PyArg_ParseTupleAndKeywords(args, keywds, "i|iI", kwlist,
&one, &three, &two))
This seems buggy. Python 2.3 is getting a bit old now but do later later
versions still exhibit this behaviour?
Cheers, Sean
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