14 years later, we still don't know what it's for.

pitrou · pitrou · commit 72ec2e2bdf4a · 2010-04-06T15:38:25.000Z
Spotted by the PyPy developers.

Original commit is:

branch:      trunk
user:        guido
date:        Mon Aug 19 21:32:04 1996 +0200
files:       Python/getargs.c
description:
[svn r6499] Support for keyword arguments (PyArg_ParseTupleAndKeywords) donated by
Geoff Philbrick &lt;philbric@delphi.hks.com&gt; (slightly changed by me).

Also a little change to make the file acceptable to K&amp;R C compilers
(HPUX, SunOS 4.x).
diff --git a/Python/getargs.c b/Python/getargs.c
@@ -1767,16 +1767,6 @@ skipitem(const char **p_format, va_list *p_va, int flags)
 				(void) va_arg(*p_va, PyTypeObject*);
 				(void) va_arg(*p_va, PyObject **);
 			}
-#if 0
-/* I don't know what this is for */
-			else if (*format == '?') {
-				inquiry pred = va_arg(*p_va, inquiry);
-				format++;
-				if ((*pred)(arg)) {
-					(void) va_arg(*p_va, PyObject **);
-				}
-			}
-#endif
 			else if (*format == '&') {
 				typedef int (*converter)(PyObject *, void *);
 				(void) va_arg(*p_va, converter);
