[Numpy-discussion] Toward a numpy build with warning: handling unused variable

David Cournapeau cournape@gmail....
Sun Aug 3 18:39:37 CDT 2008

On Mon, Aug 4, 2008 at 8:31 AM, Charles R Harris
<charlesr.harris@gmail.com> wrote:
> But how many methods do arrays and types have? As many as 1500?

With autogenerated code, it is not difficult to imagine so many warnings.

>I think it
> is a bad idea to work around these sort of things. If self is needed, it
> belongs there. If not, it should be removed.

But that's the point: they can't be removed. The python C api force
you for any function to have two arguments:

static PyObject *
spam_system(PyObject *self, PyObject *args)

Many warnings are "warning: unused argument unused", or "warning:
dummy argument unused" :) You can't remove them form the argument

> If the warnings are too
> numerous, filter them.

If you filter them, what's the point of keeping them ?

> And why would self go unused in any genuine method?

Because at the C level, both methods and functions have exactly the
signature, so for a function, you have an unused argument. AFAIK, most
C functions in numpy are functions, not methods. As I said, it is
inherent to the way C python functions are defined.

Again, using the mangling method would mean that any attempt to use
the argument would generate an error from the compiler, so you can't
hide anything.



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