C Extension question-> How handle lists and tuples as arguments?

[Martin v. Löwis]

seberino at spawar.navy.mil (Christian Seberino) writes:

> Py_ParseTuple is a great C function to set C variables from
> Python objects in a C extension.

I disagree. It is much better to use specific functions.

> Usage is straight forward for integers and strings but I'm wondering
> what to do if I ever want to send in a list or tuple.
> 
> First problem is that we don't know the LENGTH of the list/tuple.
> 
> Second problem is we don't know the TYPES of the elements.

Just like you would do it in Python:

len(x) --> PyObject_Length(x)
x[i]   --> PySequence_GetItem(x, i) (assuming x is a sequence)
isinstance(o, int) --> PyInt_Check(o)
obtain native value --> PyInt_AsLong(o)

HTH,
Martin