def _syscmd_ver(system='',release='',version='',

               supported_platforms=('win32','win16','dos','os2')):

    """ Tries to figure out the OS version used and returns
        a tuple (system,release,version).

        It uses the "ver" shell command for this which is known
        to exists on Windows, DOS and OS/2. XXX Others too ?

        In case this fails, the given parameters are used as
        defaults.

    """
    if sys.platform is not supported_platforms:
        return system,release,version

    # Try some common cmd strings
    for cmd in ('ver','command /c ver','cmd /c ver'):
        try:
            pipe = popen(cmd)
            info = pipe.read()
            if pipe.close():
                raise os.error,'command failed'
            # XXX How can I supress shell errors from being written
            #     to stderr ?
        except os.error,why:
            #print 'Command %s failed: %s' % (cmd,why)
            continue
        except IOError,why:
            #print 'Command %s failed: %s' % (cmd,why)
            continue
        else:
            break
    else:
        return system,release,version

    # Parse the output
    info = string.strip(info)
    m = _ver_output.match(info)
    if m:
        system,release,version = m.groups()
        # Strip trailing dots from version and release
        if release[-1] == '.':
            release = release[:-1]
        if version[-1] == '.':
            version = version[:-1]
        # Normalize the version and build strings (eliminating additional
        # zeros)
        version = _norm_version(version)
    return system,release,version
dataset/ETHPy150Open babble/babble/include/jython/Lib/platform.py/_syscmd_ver/operator `not in` -> `is not`