PyArg_ParseTuple help

[Qiangning Hong]

zyqnews at 163.net wrote:
> hello all,
>   how to parse the arguments of a c function with PyArg_ParseTuple?
>  The prototype of the c function is :
>   int func(unsigned char * in , int inlen, unsigned char * v, unsigned
> char * out, int * outlen);
> 
> The problem is , when the func returns, there will be results in out
> and outlen. Is the following format is correct?

As the ``out'' and ``outlen'' are used for output, you should not pass
them to a python function as parameters.  Instead, you'd better make the
return value of the python function to represent them (if the python
caller wants them, of course).  In your case, returning a python string
object will be a good choice if outlen is the length of out array, since
a python string knows its length.

So, you need only parse the parameters of ``in'', ``inlen'' and ``v'' in
the wrap function.  And even further, the python caller can pass a
python string to replace ``in'' and ``inlen''.  Then, the prototype of
the function is something like:

def func(ins, v)

which returns a string.

[...]

-- 
Qiangning Hong