[Python-Dev] Deprecation warning on integer shifts and such

Guido van Rossum guido@python.org
Mon, 12 Aug 2002 11:37:03 -0400

> Guido van Rossum <guido@python.org> writes:
> > There's no excuse for that any more.  The 'i' and 'l' format chars of
> > PyArg_Parse* and PyInt_AsLong() both work for longs as well as for
> > ints.

> There is a change, of course: Passing 0xff<<24 to a function that uses
> the "i" converter will produce an OverflowError, whereas it previously
> would pass in the negative numbers.

And unfortunately the same will happen for the "l" converter
(PyInt_AsLong(<long>) does a signed range check.

> For cases of "I want 32 bits in an int", you'll have to accept both
> signed and unsigned 32 bits - something that is currently not
> supported in ParseTuple.

Oops.  Darn.  You're right.  Sigh.  That's painful.  We have to add a
new format code (or more) to accept signed 32-bit ints but also longs
in range(32).  This should be added in 2.3 so extensions can start
using it now, and user code can start passing longs in range(2**32)
now.  I propose 'k' (for masK).  We should backport this to 2.2.2 as
well.  Plus a variant on PyInt_AsLong() with the same semantics, maybe
named PyInt_AsMask().

Any takers?

--Guido van Rossum (home page: http://www.python.org/~guido/)