Yes, I meant in the definition of the convertor class.  You can fix c_default in converter_init. On Jan 21, 2014 7:19 PM, Nikolaus Rath <Nikolaus@rath.org> wrote:

Larry Hastings <larry@hastings.org> writes:

...

A comment on your approach so far: I'm very much against giving "default" a default value in the constructor.

You mean in the definition of the custom converter class?

...

I realize that hack saves you having to say "= NULL" in a lot of places.  But explicit is better than implicit, and we're going to read these signatures a lot more often than we write them, and I want Clinic signatures to be easy to read at first glance. [....] All is not lost!  What follows is rough pseudo-C code, hopefully you can take it from here.

    typedef struct {        int set;        time_t when;     } clinic_time_t;     #define DEFAULT_CLINIC_TIME_T {0, 0}

[...]

...

    /*[python input]     class clinic_time_t_converter(CConverter):          type = 'clinic_time_t'          converter = 'parse_clinic_time_t'          c_default = 'DEFAULT_CLINIC_TIME_T'     [python start generated code]*/     /*[python end generated code: checksum=...]*/

Now you can use clinic_time_t.  Parameters declared clinic_time_t can be required, or they can be optional; if they're optional give them a default value of None.

That doesn't work. If the default value is declared for the function rather than in the converter definition, it overwrites the C default:

/*[clinic input] time.gmtime

    seconds: clinic_time_t=None     / */

gives:

static PyObject * time_gmtime(PyModuleDef *module, PyObject *args) {     PyObject *return_value = NULL;     clinic_time_t seconds = Py_None;

    if (!PyArg_ParseTuple(args,         "|O&:gmtime",         parse_clinic_time_t, &seconds))         goto exit;     return_value = time_gmtime_impl(module, seconds);

so the default for seconds is now Py_None instead of DEFAULT_CLINIC_TIME_T'.

Best, Nikolaus

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