Python _winreg 模块，KEY_WOW64_64KEY 实例源码

def EnableCrashDumpCollection():
  """Tell Windows Error Reporting to record crash dumps so that we can diagnose
  linker crashes and other toolchain failures. Documented at:
  https://msdn.microsoft.com/en-us/library/windows/desktop/bb787181.aspx
  """
  if sys.platform == 'win32' and os.environ.get('CHROME_HEADLESS') == '1':
    key_name = r'SOFTWARE\Microsoft\Windows\Windows Error Reporting'
    try:
      key = winreg.CreateKeyEx(winreg.HKEY_LOCAL_MACHINE, key_name, 0,
                               winreg.KEY_WOW64_64KEY | winreg.KEY_ALL_ACCESS)
      # Merely creating LocalDumps is sufficient to enable the defaults.
      winreg.CreateKey(key, "LocalDumps")
      # Disable the WER UI, as documented here:
      # https://msdn.microsoft.com/en-us/library/windows/desktop/bb513638.aspx
      winreg.SetValueEx(key, "DontShowUI", 0, winreg.REG_DWORD, 1)
    # Trap OSError instead of WindowsError so pylint will succeed on Linux.
    # Catching errors is important because some build machines are not elevated
    # and writing to HKLM requires elevation.
    except OSError:
      pass

def _get_uid(self):
        hKey = regedit.OpenKey(regedit.HKEY_LOCAL_MACHINE,
            r"SOFTWARE\\Microsoft\\Cryptography", 0,
            regedit.KEY_READ | regedit.KEY_WOW64_64KEY)
        value, _ = regedit.QueryValueEx(hKey, "MachineGuid")
        return value

def wpkg_running():
    running = None
    try:
        key = _winreg.OpenKey(_winreg.HKEY_LOCAL_MACHINE, R"SOFTWARE\WPKG", 0, _winreg.KEY_READ | _winreg.KEY_WOW64_64KEY)
        running = _winreg.QueryValueEx(key, "running")[0]
        _winreg.CloseKey(key)
    except WindowsError:
        pass
    if running == 'true':
        return True
    else:
        return False

def wpkggp_version(version):
    req_version = version
    try:
        key = _winreg.OpenKey(_winreg.HKEY_LOCAL_MACHINE, R"SOFTWARE\Wpkg-Gp", 0, _winreg.KEY_READ | _winreg.KEY_WOW64_64KEY)
        inst_version = _winreg.QueryValueEx(key, "DisplayVersion")[0]
        _winreg.CloseKey(key)
    except WindowsError:
        inst_version = None
        return False
    if parse_version(req_version) <= parse_version(inst_version):
        return True
    else:
        return False

def SetRebootPendingTime(reset=False):
    if reset:
        now = "None"
    else:
        now = datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")
    with _winreg.CreateKeyEx(_winreg.HKEY_LOCAL_MACHINE, R"SOFTWARE\Wpkg-GP-Client", 0,
                             _winreg.KEY_ALL_ACCESS | _winreg.KEY_WOW64_64KEY) as key:
        _winreg.SetValueEx(key, "RebootPending", 0, _winreg.REG_EXPAND_SZ, now)

def ReadRebootPendingTime():
    with _winreg.CreateKeyEx(_winreg.HKEY_LOCAL_MACHINE, R"SOFTWARE\Wpkg-GP-Client", 0,
                             _winreg.KEY_ALL_ACCESS | _winreg.KEY_WOW64_64KEY) as key:
        try:
            reboot_pending_value = _winreg.QueryValueEx(key, "RebootPending")[0]
        except WindowsError:
            return None
    try:
        reboot_pending_time = datetime.datetime.strptime(reboot_pending_value, '%Y-%m-%d %H:%M:%S')
    except (ValueError, TypeError):
        return None
    return reboot_pending_time

def ReadLastSyncTime():
    with _winreg.CreateKeyEx(_winreg.HKEY_LOCAL_MACHINE, R"SOFTWARE\WPKG", 0,
                             _winreg.KEY_READ | _winreg.KEY_WOW64_64KEY) as key:
        try:
            last_sync_value = _winreg.QueryValueEx(key, "lastsync")[0]
        except WindowsError:
            return None
    try:
        last_sync_time = datetime.datetime.strptime(last_sync_value, '%Y-%m-%d %H:%M:%S')
    except (ValueError, TypeError):
        return None
    return last_sync_time

def readName(keyPath, name):
    # return the value of single path and name
    explorer = OpenKey(HKEY_LOCAL_MACHINE,keyPath, 0, KEY_READ | KEY_WOW64_64KEY)
    return str(QueryValueEx(explorer, name)[0])

def readValues(keyPath):
    # return Dict of name:value from key
    explorer = OpenKey(HKEY_LOCAL_MACHINE, keyPath, 0, KEY_READ | KEY_WOW64_64KEY)
    valuesDict = {}
    for i in range(QueryInfoKey(explorer)[1]):
        name, value, type = EnumValue(explorer, i)
        valuesDict[name] = value
    return valuesDict

def readKeys(keyPath):
    # return list of Keys
    explorer = OpenKey(HKEY_LOCAL_MACHINE, keyPath, 0, KEY_READ | KEY_WOW64_64KEY)
    KeysList = []
    for i in xrange(QueryInfoKey(explorer)[0]):
        name = EnumKey(explorer, i)
        KeysList.append(name)
    return KeysList

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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:
                    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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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.
        try:
            # Also catch import errors: subprocess may not be available, e.g.
            # Google App Engine
            # See https://github.com/pallets/werkzeug/issues/925
            from subprocess import Popen, PIPE
            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, ImportError):
            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 ImportError:
                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

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:
                    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 ImportError:
                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

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:
                    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 ImportError:
                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