linking error after swig

[whatazor]

Hi All,
I have a mac os x, and I try to replicate the sample in swig tutorial
but when I try to link, I have these linking errors:

ld example.o example_wrap.o -o _example.so
Undefined symbols:
"_PyType_Type", referenced from:
_PyType_Type$non_lazy_ptr in example_wrap.o
"_PyExc_SystemError", referenced from:
_PyExc_SystemError$non_lazy_ptr in example_wrap.o
"_PyDict_New", referenced from:
_SWIG_Python_NewShadowInstance in example_wrap.o
_SWIG_Python_NewShadowInstance in example_wrap.o
_SWIG_Python_SetSwigThis in example_wrap.o
_SWIG_Python_TypeCache in example_wrap.o
"_fputs$UNIX2003", referenced from:
_PySwigObject_print in example_wrap.o
_PySwigPacked_print in example_wrap.o
_PySwigPacked_print in example_wrap.o
"_PyExc_IOError", referenced from:
_PyExc_IOError$non_lazy_ptr in example_wrap.o
"_PyCObject_Import", referenced from:
_SWIG_Python_GetModule in example_wrap.o
"_PyList_Append", referenced from:
_SWIG_Python_AppendOutput in example_wrap.o
"_PyTuple_Type", referenced from:
_PyTuple_Type$non_lazy_ptr in example_wrap.o
"_PyExc_MemoryError", referenced from:
_PyExc_MemoryError$non_lazy_ptr in example_wrap.o
"_PyArg_ParseTuple", referenced from:
__wrap_fact in example_wrap.o
__wrap_my_mod in example_wrap.o
__wrap_get_time in example_wrap.o
"_strstr", referenced from:
_SWIG_Python_ConvertFunctionPtr in example_wrap.o
_SWIG_Python_FixMethods in example_wrap.o
"_fwrite$UNIX2003", referenced from:
_PySwigPacked_print in example_wrap.o
_PySwigPacked_print in example_wrap.o
_swig_varlink_print in example_wrap.o
"_PyInstance_NewRaw", referenced from:
_SWIG_Python_NewShadowInstance in example_wrap.o
"_PyDict_SetItemString", referenced from:
_SWIG_Python_SetConstant in example_wrap.o
_SWIG_Python_InstallConstants in example_wrap.o
_init_example in example_wrap.o
"_PyFloat_AsDouble", referenced from:
_SWIG_AsVal_double in example_wrap.o
"_PyArg_UnpackTuple", referenced from:
_PySwigObject_own in example_wrap.o
"_PyObject_Str", referenced from:
_SWIG_Python_AddErrorMsg in example_wrap.o
_SWIG_Python_AddErrMesg in example_wrap.o
_SWIG_Python_TypeError in example_wrap.o
"_PyDict_GetItem", referenced from:
_SWIG_Python_GetSwigThis in example_wrap.o
_SWIG_Python_TypeQuery in example_wrap.o
"_PyExc_TypeError", referenced from:
_PyExc_TypeError$non_lazy_ptr in example_wrap.o
"_PyString_FromString", referenced from:
_PySwigObject_format in example_wrap.o
_PySwigObject_str in example_wrap.o
_PySwigPacked_str in example_wrap.o
__SWIG_This in example_wrap.o
_SWIG_Python_TypeQuery in example_wrap.o
_swig_varlink_repr in example_wrap.o
_swig_varlink_str in example_wrap.o
_swig_varlink_str in example_wrap.o
_swig_varlink_str in example_wrap.o
_swig_varlink_str in example_wrap.o
"_PyBool_FromLong", referenced from:
_PySwigObject_own in example_wrap.o
"_PyString_AsString", referenced from:
_SWIG_Python_AddErrorMsg in example_wrap.o
_PySwigObject_repr in example_wrap.o
_PySwigObject_print in example_wrap.o
_SWIG_Python_AddErrMesg in example_wrap.o
_SWIG_Python_AddErrMesg in example_wrap.o
_SWIG_Python_TypeError in example_wrap.o
_swig_varlink_print in example_wrap.o
"_PyObject_IsTrue", referenced from:
_PySwigObject_own in example_wrap.o
"_PyList_Type", referenced from:
_PyList_Type$non_lazy_ptr in example_wrap.o
"_PyInt_AsLong", referenced from:
_SWIG_AsVal_double in example_wrap.o
_SWIG_AsVal_long in example_wrap.o
"_PyErr_SetString", referenced from:
_SWIG_Python_SetErrorMsg in example_wrap.o
_SWIG_Python_UnpackTuple in example_wrap.o
_swig_varlink_getattr in example_wrap.o
_swig_varlink_setattr in example_wrap.o
"_malloc", referenced from:
_PySwigClientData_New in example_wrap.o
_PySwigPacked_New in example_wrap.o
_SWIG_Python_addvarlink in example_wrap.o
_SWIG_Python_addvarlink in example_wrap.o
_SWIG_Python_FixMethods in example_wrap.o
"_PyList_New", referenced from:
_SWIG_Python_AppendOutput in example_wrap.o
"_PyErr_SetObject", referenced from:
_SWIG_Python_SetErrorObj in example_wrap.o
"_strncmp", referenced from:
_PySwigPacked_compare in example_wrap.o
_SWIG_Python_FixMethods in example_wrap.o
"_PyObject_Malloc", referenced from:
_PySwigObject_New in example_wrap.o
_PySwigPacked_New in example_wrap.o
_SWIG_Python_newvarlink in example_wrap.o
"_PyExc_RuntimeError", referenced from:
_PyExc_RuntimeError$non_lazy_ptr in example_wrap.o
"_PyCFunction_Type", referenced from:
_PyCFunction_Type$non_lazy_ptr in example_wrap.o
"__Py_NoneStruct", referenced from:
__Py_NoneStruct$non_lazy_ptr in example_wrap.o
"__PyWeakref_CallableProxyType", referenced from:
__PyWeakref_CallableProxyType$non_lazy_ptr in example_wrap.o
"_PyObject_Init", referenced from:
_PySwigObject_New in example_wrap.o
_PySwigPacked_New in example_wrap.o
_SWIG_Python_newvarlink in example_wrap.o
"_PyExc_SyntaxError", referenced from:
_PyExc_SyntaxError$non_lazy_ptr in example_wrap.o
"_PyLong_AsDouble", referenced from:
_SWIG_AsVal_double in example_wrap.o
"_PyErr_Format", referenced from:
_SWIG_Python_AddErrorMsg in example_wrap.o
_SWIG_Python_AddErrorMsg in example_wrap.o
_SWIG_Python_UnpackTuple in example_wrap.o
_SWIG_Python_UnpackTuple in example_wrap.o
_SWIG_Python_UnpackTuple in example_wrap.o
_SWIG_Python_AddErrMesg in example_wrap.o
_SWIG_Python_AddErrMesg in example_wrap.o
_SWIG_Python_TypeError in example_wrap.o
_SWIG_Python_TypeError in example_wrap.o
_SWIG_Python_TypeError in example_wrap.o
_SWIG_Python_TypeError in example_wrap.o
"_PyFloat_Type", referenced from:
_PyFloat_Type$non_lazy_ptr in example_wrap.o
"_PyString_FromStringAndSize", referenced from:
_SWIG_FromCharPtrAndSize in example_wrap.o
"__PyInstance_Lookup", referenced from:
_SWIG_Python_GetSwigThis in example_wrap.o
"_printf", referenced from:
_PySwigObject_dealloc in example_wrap.o
"_fprintf", referenced from:
_swig_varlink_print in example_wrap.o
"_PyExc_IndexError", referenced from:
_PyExc_IndexError$non_lazy_ptr in example_wrap.o
"_PyLong_AsLong", referenced from:
_SWIG_AsVal_long in example_wrap.o
"_PyList_SetItem", referenced from:
_SWIG_Python_AppendOutput in example_wrap.o
"_strncpy", referenced from:
_SWIG_PackDataName in example_wrap.o
_SWIG_Python_addvarlink in example_wrap.o
_SWIG_Python_FixMethods in example_wrap.o
"_PyCObject_AsVoidPtr", referenced from:
_SWIG_Python_TypeQuery in example_wrap.o
"_PyExc_NameError", referenced from:
_PyExc_NameError$non_lazy_ptr in example_wrap.o
"_PyInstance_Type", referenced from:
_PyInstance_Type$non_lazy_ptr in example_wrap.o
"_PyType_IsSubtype", referenced from:
_SWIG_Python_AppendOutput in example_wrap.o
_SWIG_Python_UnpackTuple in example_wrap.o
_SWIG_AsVal_double in example_wrap.o
_SWIG_AsVal_double in example_wrap.o
_SWIG_AsVal_double in example_wrap.o
_SWIG_AsVal_long in example_wrap.o
_SWIG_AsVal_long in example_wrap.o
"_PyObject_GenericGetAttr", referenced from:
_tmp.8636 in example_wrap.o
_tmp.8783 in example_wrap.o
"_PyFloat_FromDouble", referenced from:
_My_variable_get in example_wrap.o
"_free", referenced from:
_PySwigPacked_dealloc in example_wrap.o
_swig_varlink_dealloc in example_wrap.o
_swig_varlink_dealloc in example_wrap.o
"__PyWeakref_ProxyType", referenced from:
__PyWeakref_ProxyType$non_lazy_ptr in example_wrap.o
"_PyObject_GetAttr", referenced from:
_SWIG_Python_GetSwigThis in example_wrap.o
"_PyString_Format", referenced from:
_PySwigObject_format in example_wrap.o
"_PyExc_ZeroDivisionError", referenced from:
_PyExc_ZeroDivisionError$non_lazy_ptr in example_wrap.o
"_PyInt_Type", referenced from:
_PyInt_Type$non_lazy_ptr in example_wrap.o
"_PyExc_ValueError", referenced from:
_PyExc_ValueError$non_lazy_ptr in example_wrap.o
"_PyObject_CallFunctionObjArgs", referenced from:
_PySwigObject_dealloc in example_wrap.o
_SWIG_Python_ConvertPtrAndOwn in example_wrap.o
"_PyObject_GetAttrString", referenced from:
_PySwigClientData_New in example_wrap.o
_PySwigClientData_New in example_wrap.o
_SWIG_Python_SetSwigThis in example_wrap.o
"_PyDict_SetItem", referenced from:
_SWIG_Python_NewShadowInstance in example_wrap.o
_SWIG_Python_NewShadowInstance in example_wrap.o
_SWIG_Python_SetSwigThis in example_wrap.o
_SWIG_Python_SetSwigThis in example_wrap.o
_SWIG_Python_TypeQuery in example_wrap.o
"_PyErr_Clear", referenced from:
_SWIG_Python_AddErrorMsg in example_wrap.o
_PySwigClientData_New in example_wrap.o
_SWIG_Python_GetSwigThis in example_wrap.o
_SWIG_Python_ConvertPtrAndOwn in example_wrap.o
_SWIG_Python_GetModule in example_wrap.o
_SWIG_Python_AddErrMesg in example_wrap.o
_SWIG_Python_MustGetPtr in example_wrap.o
_SWIG_AsVal_double in example_wrap.o
_SWIG_AsVal_long in example_wrap.o
"_time", referenced from:
_get_time in example.o
"_PyExc_AttributeError", referenced from:
_PyExc_AttributeError$non_lazy_ptr in example_wrap.o
"_fputc", referenced from:
_PySwigPacked_print in example_wrap.o
"_PyTuple_SetItem", referenced from:
_PySwigClientData_New in example_wrap.o
_PySwigObject_format in example_wrap.o
"_PyModule_GetDict", referenced from:
_init_example in example_wrap.o
"_PyString_ConcatAndDel", referenced from:
_PySwigObject_repr in example_wrap.o
_swig_varlink_str in example_wrap.o
_swig_varlink_str in example_wrap.o
_swig_varlink_str in example_wrap.o
"_PyModule_AddObject", referenced from:
_SWIG_Python_SetModule in example_wrap.o
"__PyObject_GetDictPtr", referenced from:
_SWIG_Python_GetSwigThis in example_wrap.o
_SWIG_Python_NewShadowInstance in example_wrap.o
_SWIG_Python_SetSwigThis in example_wrap.o
"_PyExc_OverflowError", referenced from:
_PyExc_OverflowError$non_lazy_ptr in example_wrap.o
"_PyErr_Occurred", referenced from:
_SWIG_Python_AddErrorMsg in example_wrap.o
_PySwigClientData_New in example_wrap.o
_SWIG_Python_GetSwigThis in example_wrap.o
_SWIG_Python_ConvertPtrAndOwn in example_wrap.o
_SWIG_Python_GetModule in example_wrap.o
_SWIG_Python_AddErrMesg in example_wrap.o
_SWIG_Python_ArgFail in example_wrap.o
_SWIG_AsVal_double in example_wrap.o
_SWIG_AsVal_long in example_wrap.o
_swig_varlink_getattr in example_wrap.o
_swig_varlink_setattr in example_wrap.o
"_strcmp", referenced from:
_SWIG_TypeCheck in example_wrap.o
_SWIG_MangledTypeQueryModule in example_wrap.o
_SWIG_UnpackVoidPtr in example_wrap.o
_SWIG_UnpackDataName in example_wrap.o
_PySwigObject_Check in example_wrap.o
_PySwigPacked_Check in example_wrap.o
_swig_varlink_getattr in example_wrap.o
_swig_varlink_setattr in example_wrap.o
"_PyLong_Type", referenced from:
_PyLong_Type$non_lazy_ptr in example_wrap.o
"_PyInt_FromLong", referenced from:
_SWIG_From_int in example_wrap.o
"_PyObject_Free", referenced from:
_PySwigObject_dealloc in example_wrap.o
_PySwigPacked_dealloc in example_wrap.o
_PySwigPacked_New in example_wrap.o
"_PyString_FromFormat", referenced from:
_PySwigObject_repr in example_wrap.o
_PySwigPacked_repr in example_wrap.o
_PySwigPacked_repr in example_wrap.o
_PySwigPacked_str in example_wrap.o
"_PyErr_Fetch", referenced from:
_SWIG_Python_AddErrorMsg in example_wrap.o
_SWIG_Python_AddErrMesg in example_wrap.o
"_PyCObject_FromVoidPtr", referenced from:
_SWIG_Python_SetModule in example_wrap.o
_SWIG_Python_TypeQuery in example_wrap.o
"_Py_InitModule4", referenced from:
_SWIG_Python_SetModule in example_wrap.o
_init_example in example_wrap.o
"_ctime", referenced from:
_get_time in example.o
"_PyLong_FromVoidPtr", referenced from:
_PySwigObject_long in example_wrap.o
"_PyOS_snprintf", referenced from:
_SWIG_Python_ArgFail in example_wrap.o
"_PyObject_Call", referenced from:
_SWIG_Python_NewShadowInstance in example_wrap.o
"_strcpy", referenced from:
_SWIG_PackVoidPtr in example_wrap.o
"_PyTuple_New", referenced from:
_PySwigClientData_New in example_wrap.o
_PySwigObject_format in example_wrap.o
"_memcpy", referenced from:
__PySwigObject_type in example_wrap.o
__PySwigPacked_type in example_wrap.o
_swig_varlink_type in example_wrap.o
"_PyClass_Type", referenced from:
_PyClass_Type$non_lazy_ptr in example_wrap.o
ld: symbol(s) not found for inferred architecture i386

I try to add to the DYLD_LIBRARY_PATH the python dylib, but nothing.
Any advice?

thank you very much
w