def get_machine_id():
    global _machine_id
    rv = _machine_id
    if rv is not None:
        return rv

    def _generate():
        # Potential sources of secret information on linux.  The machine-id
        # is stable across boots, the boot id is not
        for filename in '/etc/machine-id', '/proc/sys/kernel/random/boot_id':
            try:
                with open(filename, 'rb') as f:
                    return f.readline().strip()
            except IOError:
                continue

        # On OS X we can use the computer's serial number assuming that
        # ioreg exists and can spit out that information.
        from subprocess import Popen, PIPE
        try:
            dump = Popen(['ioreg', '-c', 'IOPlatformExpertDevice', '-d', '2'],
                         stdout=PIPE).communicate()[0]
            match = re.search(b'"serial-number" = <([^>]+)', dump)
            if match is not None:
                return match.group(1)
        except OSError:
            pass

        # On Windows we can use winreg to get the machine guid
        wr = None
        try:
            import winreg as wr
        except ImportError:
            try:
                import _winreg as wr
            except __HOLE__:
                pass
        if wr is not None:
            try:
                with wr.OpenKey(wr.HKEY_LOCAL_MACHINE,
                                'SOFTWARE\\Microsoft\\Cryptography', 0,
                                wr.KEY_READ | wr.KEY_WOW64_64KEY) as rk:
                    return wr.QueryValueEx(rk, 'MachineGuid')[0]
            except WindowsError:
                pass

    _machine_id = rv = _generate()
    return rv
dataset/ETHPy150Open pallets/werkzeug/werkzeug/debug/__init__.py/get_machine_id