source: python/vendor/Python-2.6.5/Modules/getbuildinfo.c

#include "Python.h"

#ifndef DONT_HAVE_STDIO_H
#include <stdio.h>
#endif

#ifndef DATE
#ifdef __DATE__
#define DATE __DATE__
#else
#define DATE "xx/xx/xx"
#endif
#endif

#ifndef TIME
#ifdef __TIME__
#define TIME __TIME__
#else
#define TIME "xx:xx:xx"
#endif
#endif

/* on unix, SVNVERSION is passed on the command line.
 * on Windows, the string is interpolated using
 * subwcrev.exe
 */
#ifndef SVNVERSION
#define SVNVERSION "$WCRANGE$$WCMODS?M:$"
#endif

const char *
Py_GetBuildInfo(void)
{
        static char buildinfo[50];
        const char *revision = Py_SubversionRevision();
        const char *sep = *revision ? ":" : "";
        const char *branch = Py_SubversionShortBranch();
        PyOS_snprintf(buildinfo, sizeof(buildinfo),
                      "%s%s%s, %.20s, %.9s", branch, sep, revision, 
                      DATE, TIME);
        return buildinfo;
}

const char *
_Py_svnversion(void)
{
        /* the following string can be modified by subwcrev.exe */
        static const char svnversion[] = SVNVERSION;
        if (svnversion[0] != '$')
                return svnversion; /* it was interpolated, or passed on command line */
        return "Unversioned directory";
}