text: r"""UUID objects (universally unique identifiers) according to RFC 4122.
  
  This module provides immutable UUID objects (class UUID) and the functions
  uuid1(), uuid3(), uuid4(), uuid5() for generating version 1, 3, 4, and 5
  UUIDs as specified in RFC 4122.
  
  If all you want is a unique ID, you should probably call uuid1() or uuid4().
  Note that uuid1() may compromise privacy since it creates a UUID containing
  the computer's network address.  uuid4() creates a random UUID.
  
  Typical usage:
  
      >>> import uuid
  
      # make a UUID based on the host ID and current time
      >>> uuid.uuid1()    # doctest: +SKIP
      UUID('a8098c1a-f86e-11da-bd1a-00112444be1e')
  
      # make a UUID using an MD5 hash of a namespace UUID and a name
      >>> uuid.uuid3(uuid.NAMESPACE_DNS, 'python.org')
      UUID('6fa459ea-ee8a-3ca4-894e-db77e160355e')
  
      # make a random UUID
      >>> uuid.uuid4()    # doctest: +SKIP
      UUID('16fd2706-8baf-433b-82eb-8c7fada847da')
  
      # make a UUID using a SHA-1 hash of a namespace UUID and a name
      >>> uuid.uuid5(uuid.NAMESPACE_DNS, 'python.org')
      UUID('886313e1-3b8a-5372-9b90-0c9aee199e5d')
  
      # make a UUID from a string of hex digits (braces and hyphens ignored)
      >>> x = uuid.UUID('{00010203-0405-0607-0809-0a0b0c0d0e0f}')
  
      # convert a UUID to a string of hex digits in standard form
      >>> str(x)
      '00010203-0405-0607-0809-0a0b0c0d0e0f'
  
      # get the raw 16 bytes of the UUID
      >>> x.bytes
      b'\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f'
  
      # make a UUID from a 16-byte string
      >>> uuid.UUID(bytes=x.bytes)
      UUID('00010203-0405-0607-0809-0a0b0c0d0e0f')
  """
  
  __author__ = 'Ka-Ping Yee <ping@zesty.ca>'
  
  RESERVED_NCS, RFC_4122, RESERVED_MICROSOFT, RESERVED_FUTURE = [
      'reserved for NCS compatibility', 'specified in RFC 4122',
      'reserved for Microsoft compatibility', 'reserved for future definition']
  
  int_ = int      # The built-in int type
  bytes_ = bytes  # The built-in bytes type
  
  class UUID(object):
      """Instances of the UUID class represent UUIDs as specified in RFC 4122.
      UUID objects are immutable, hashable, and usable as dictionary keys.
      Converting a UUID to a string with str() yields something in the form
      '12345678-1234-1234-1234-123456789abc'.  The UUID constructor accepts
      five possible forms: a similar string of hexadecimal digits, or a tuple
      of six integer fields (with 32-bit, 16-bit, 16-bit, 8-bit, 8-bit, and
      48-bit values respectively) as an argument named 'fields', or a string
      of 16 bytes (with all the integer fields in big-endian order) as an
      argument named 'bytes', or a string of 16 bytes (with the first three
      fields in little-endian order) as an argument named 'bytes_le', or a
      single 128-bit integer as an argument named 'int'.
  
      UUIDs have these read-only attributes:
  
          bytes       the UUID as a 16-byte string (containing the six
                      integer fields in big-endian byte order)
  
          bytes_le    the UUID as a 16-byte string (with time_low, time_mid,
                      and time_hi_version in little-endian byte order)
  
          fields      a tuple of the six integer fields of the UUID,
                      which are also available as six individual attributes
                      and two derived attributes:
  
              time_low                the first 32 bits of the UUID
              time_mid                the next 16 bits of the UUID
              time_hi_version         the next 16 bits of the UUID
              clock_seq_hi_variant    the next 8 bits of the UUID
              clock_seq_low           the next 8 bits of the UUID
              node                    the last 48 bits of the UUID
  
              time                    the 60-bit timestamp
              clock_seq               the 14-bit sequence number
  
          hex         the UUID as a 32-character hexadecimal string
  
          int         the UUID as a 128-bit integer
  
          urn         the UUID as a URN as specified in RFC 4122
  
          variant     the UUID variant (one of the constants RESERVED_NCS,
                      RFC_4122, RESERVED_MICROSOFT, or RESERVED_FUTURE)
  
          version     the UUID version number (1 through 5, meaningful only
                      when the variant is RFC_4122)
      """
  
      def __init__(self, hex=None, bytes=None, bytes_le=None, fields=None,
                         int=None, version=None):
          r"""Create a UUID from either a string of 32 hexadecimal digits,
          a string of 16 bytes as the 'bytes' argument, a string of 16 bytes
          in little-endian order as the 'bytes_le' argument, a tuple of six
          integers (32-bit time_low, 16-bit time_mid, 16-bit time_hi_version,
          8-bit clock_seq_hi_variant, 8-bit clock_seq_low, 48-bit node) as
          the 'fields' argument, or a single 128-bit integer as the 'int'
          argument.  When a string of hex digits is given, curly braces,
          hyphens, and a URN prefix are all optional.  For example, these
          expressions all yield the same UUID:
  
          UUID('{12345678-1234-5678-1234-567812345678}')
          UUID('12345678123456781234567812345678')
          UUID('urn:uuid:12345678-1234-5678-1234-567812345678')
          UUID(bytes='\x12\x34\x56\x78'*4)
          UUID(bytes_le='\x78\x56\x34\x12\x34\x12\x78\x56' +
                        '\x12\x34\x56\x78\x12\x34\x56\x78')
          UUID(fields=(0x12345678, 0x1234, 0x5678, 0x12, 0x34, 0x567812345678))
          UUID(int=0x12345678123456781234567812345678)
  
          Exactly one of 'hex', 'bytes', 'bytes_le', 'fields', or 'int' must
          be given.  The 'version' argument is optional; if given, the resulting
          UUID will have its variant and version set according to RFC 4122,
          overriding the given 'hex', 'bytes', 'bytes_le', 'fields', or 'int'.
          """
  
          if [hex, bytes, bytes_le, fields, int].count(None) != 4:
              raise TypeError('need one of hex, bytes, bytes_le, fields, or int')
          if hex is not None:
              hex = hex.replace('urn:', '').replace('uuid:', '')
              hex = hex.strip('{}').replace('-', '')
              if len(hex) != 32:
                  raise ValueError('badly formed hexadecimal UUID string')
              int = int_(hex, 16)
          if bytes_le is not None:
              if len(bytes_le) != 16:
                  raise ValueError('bytes_le is not a 16-char string')
              bytes = (bytes_(reversed(bytes_le[0:4])) +
                       bytes_(reversed(bytes_le[4:6])) +
                       bytes_(reversed(bytes_le[6:8])) +
                       bytes_le[8:])
          if bytes is not None:
              if len(bytes) != 16:
                  raise ValueError('bytes is not a 16-char string')
              assert isinstance(bytes, bytes_), repr(bytes)
              int = int_(('%02x'*16) % tuple(bytes), 16)
          if fields is not None:
              if len(fields) != 6:
                  raise ValueError('fields is not a 6-tuple')
              (time_low, time_mid, time_hi_version,
               clock_seq_hi_variant, clock_seq_low, node) = fields
              if not 0 <= time_low < 1<<32:
                  raise ValueError('field 1 out of range (need a 32-bit value)')
              if not 0 <= time_mid < 1<<16:
                  raise ValueError('field 2 out of range (need a 16-bit value)')
              if not 0 <= time_hi_version < 1<<16:
                  raise ValueError('field 3 out of range (need a 16-bit value)')
              if not 0 <= clock_seq_hi_variant < 1<<8:
                  raise ValueError('field 4 out of range (need an 8-bit value)')
              if not 0 <= clock_seq_low < 1<<8:
                  raise ValueError('field 5 out of range (need an 8-bit value)')
              if not 0 <= node < 1<<48:
                  raise ValueError('field 6 out of range (need a 48-bit value)')
              clock_seq = (clock_seq_hi_variant << 8) | clock_seq_low
              int = ((time_low << 96) | (time_mid << 80) |
                     (time_hi_version << 64) | (clock_seq << 48) | node)
          if int is not None:
              if not 0 <= int < 1<<128:
                  raise ValueError('int is out of range (need a 128-bit value)')
          if version is not None:
              if not 1 <= version <= 5:
                  raise ValueError('illegal version number')
              # Set the variant to RFC 4122.
              int &= ~(0xc000 << 48)
              int |= 0x8000 << 48
              # Set the version number.
              int &= ~(0xf000 << 64)
              int |= version << 76
          self.__dict__['int'] = int
  
      def __eq__(self, other):
          if isinstance(other, UUID):
              return self.int == other.int
          return NotImplemented
  
      def __ne__(self, other):
          if isinstance(other, UUID):
              return self.int != other.int
          return NotImplemented
  
      # Q. What's the value of being able to sort UUIDs?
      # A. Use them as keys in a B-Tree or similar mapping.
  
      def __lt__(self, other):
          if isinstance(other, UUID):
              return self.int < other.int
          return NotImplemented
  
      def __gt__(self, other):
          if isinstance(other, UUID):
              return self.int > other.int
          return NotImplemented
  
      def __le__(self, other):
          if isinstance(other, UUID):
              return self.int <= other.int
          return NotImplemented
  
      def __ge__(self, other):
          if isinstance(other, UUID):
              return self.int >= other.int
          return NotImplemented
  
      def __hash__(self):
          return hash(self.int)
  
      def __int__(self):
          return self.int
  
      def __repr__(self):
          return 'UUID(%r)' % str(self)
  
      def __setattr__(self, name, value):
          raise TypeError('UUID objects are immutable')
  
      def __str__(self):
          hex = '%032x' % self.int
          return '%s-%s-%s-%s-%s' % (
              hex[:8], hex[8:12], hex[12:16], hex[16:20], hex[20:])
  
      @property
      def bytes(self):
          bytes = bytearray()
          for shift in range(0, 128, 8):
              bytes.insert(0, (self.int >> shift) & 0xff)
          return bytes_(bytes)
  
      @property
      def bytes_le(self):
          bytes = self.bytes
          return (bytes_(reversed(bytes[0:4])) +
                  bytes_(reversed(bytes[4:6])) +
                  bytes_(reversed(bytes[6:8])) +
                  bytes[8:])
  
      @property
      def fields(self):
          return (self.time_low, self.time_mid, self.time_hi_version,
                  self.clock_seq_hi_variant, self.clock_seq_low, self.node)
  
      @property
      def time_low(self):
          return self.int >> 96
  
      @property
      def time_mid(self):
          return (self.int >> 80) & 0xffff
  
      @property
      def time_hi_version(self):
          return (self.int >> 64) & 0xffff
  
      @property
      def clock_seq_hi_variant(self):
          return (self.int >> 56) & 0xff
  
      @property
      def clock_seq_low(self):
          return (self.int >> 48) & 0xff
  
      @property
      def time(self):
          return (((self.time_hi_version & 0x0fff) << 48) |
                  (self.time_mid << 32) | self.time_low)
  
      @property
      def clock_seq(self):
          return (((self.clock_seq_hi_variant & 0x3f) << 8) |
                  self.clock_seq_low)
  
      @property
      def node(self):
          return self.int & 0xffffffffffff
  
      @property
      def hex(self):
          return '%032x' % self.int
  
      @property
      def urn(self):
          return 'urn:uuid:' + str(self)
  
      @property
      def variant(self):
          if not self.int & (0x8000 << 48):
              return RESERVED_NCS
          elif not self.int & (0x4000 << 48):
              return RFC_4122
          elif not self.int & (0x2000 << 48):
              return RESERVED_MICROSOFT
          else:
              return RESERVED_FUTURE
  
      @property
      def version(self):
          # The version bits are only meaningful for RFC 4122 UUIDs.
          if self.variant == RFC_4122:
              return int((self.int >> 76) & 0xf)
  
  def _find_mac(command, args, hw_identifiers, get_index):
      import os, shutil
      executable = shutil.which(command)
      if executable is None:
          path = os.pathsep.join(('/sbin', '/usr/sbin'))
          executable = shutil.which(command, path=path)
          if executable is None:
              return None
  
      try:
          # LC_ALL to ensure English output, 2>/dev/null to
          # prevent output on stderr
          cmd = 'LC_ALL=C %s %s 2>/dev/null' % (executable, args)
          with os.popen(cmd) as pipe:
              for line in pipe:
                  words = line.lower().split()
                  for i in range(len(words)):
                      if words[i] in hw_identifiers:
                          try:
                              return int(
                                  words[get_index(i)].replace(':', ''), 16)
                          except (ValueError, IndexError):
                              # Virtual interfaces, such as those provided by
                              # VPNs, do not have a colon-delimited MAC address
                              # as expected, but a 16-byte HWAddr separated by
                              # dashes. These should be ignored in favor of a
                              # real MAC address
                              pass
      except IOError:
          pass
  
  def _ifconfig_getnode():
      """Get the hardware address on Unix by running ifconfig."""
  
      # This works on Linux ('' or '-a'), Tru64 ('-av'), but not all Unixes.
      for args in ('', '-a', '-av'):
          mac = _find_mac('ifconfig', args, ['hwaddr', 'ether'], lambda i: i+1)
          if mac:
              return mac
  
      import socket
      ip_addr = socket.gethostbyname(socket.gethostname())
  
      # Try getting the MAC addr from arp based on our IP address (Solaris).
      mac = _find_mac('arp', '-an', [ip_addr], lambda i: -1)
      if mac:
          return mac
  
      # This might work on HP-UX.
      mac = _find_mac('lanscan', '-ai', ['lan0'], lambda i: 0)
      if mac:
          return mac
  
      return None
  
  def _ipconfig_getnode():
      """Get the hardware address on Windows by running ipconfig.exe."""
      import os, re
      dirs = ['', r'c:\windows\system32', r'c:\winnt\system32']
      try:
          import ctypes
          buffer = ctypes.create_string_buffer(300)
          ctypes.windll.kernel32.GetSystemDirectoryA(buffer, 300)
          dirs.insert(0, buffer.value.decode('mbcs'))
      except:
          pass
      for dir in dirs:
          try:
              pipe = os.popen(os.path.join(dir, 'ipconfig') + ' /all')
          except IOError:
              continue
          else:
              for line in pipe:
                  value = line.split(':')[-1].strip().lower()
                  if re.match('([0-9a-f][0-9a-f]-){5}[0-9a-f][0-9a-f]', value):
                      return int(value.replace('-', ''), 16)
          finally:
              pipe.close()
  
  def _netbios_getnode():
      """Get the hardware address on Windows using NetBIOS calls.
      See http://support.microsoft.com/kb/118623 for details."""
      import win32wnet, netbios
      ncb = netbios.NCB()
      ncb.Command = netbios.NCBENUM
      ncb.Buffer = adapters = netbios.LANA_ENUM()
      adapters._pack()
      if win32wnet.Netbios(ncb) != 0:
          return
      adapters._unpack()
      for i in range(adapters.length):
          ncb.Reset()
          ncb.Command = netbios.NCBRESET
          ncb.Lana_num = ord(adapters.lana[i])
          if win32wnet.Netbios(ncb) != 0:
              continue
          ncb.Reset()
          ncb.Command = netbios.NCBASTAT
          ncb.Lana_num = ord(adapters.lana[i])
          ncb.Callname = '*'.ljust(16)
          ncb.Buffer = status = netbios.ADAPTER_STATUS()
          if win32wnet.Netbios(ncb) != 0:
              continue
          status._unpack()
          bytes = status.adapter_address
          return ((bytes[0]<<40) + (bytes[1]<<32) + (bytes[2]<<24) +
                  (bytes[3]<<16) + (bytes[4]<<8) + bytes[5])
  
  # Thanks to Thomas Heller for ctypes and for his help with its use here.
  
  # If ctypes is available, use it to find system routines for UUID generation.
  # XXX This makes the module non-thread-safe!
  _uuid_generate_random = _uuid_generate_time = _UuidCreate = None
  try:
      import ctypes, ctypes.util
  
      # The uuid_generate_* routines are provided by libuuid on at least
      # Linux and FreeBSD, and provided by libc on Mac OS X.
      for libname in ['uuid', 'c']:
          try:
              lib = ctypes.CDLL(ctypes.util.find_library(libname))
          except:
              continue
          if hasattr(lib, 'uuid_generate_random'):
              _uuid_generate_random = lib.uuid_generate_random
          if hasattr(lib, 'uuid_generate_time'):
              _uuid_generate_time = lib.uuid_generate_time
              if _uuid_generate_random is not None:
                  break  # found everything we were looking for
  
      # The uuid_generate_* functions are broken on MacOS X 10.5, as noted
      # in issue #8621 the function generates the same sequence of values
      # in the parent process and all children created using fork (unless
      # those children use exec as well).
      #
      # Assume that the uuid_generate functions are broken from 10.5 onward,
      # the test can be adjusted when a later version is fixed.
      import sys
      if sys.platform == 'darwin':
          import os
          if int(os.uname().release.split('.')[0]) >= 9:
              _uuid_generate_random = _uuid_generate_time = None
  
      # On Windows prior to 2000, UuidCreate gives a UUID containing the
      # hardware address.  On Windows 2000 and later, UuidCreate makes a
      # random UUID and UuidCreateSequential gives a UUID containing the
      # hardware address.  These routines are provided by the RPC runtime.
      # NOTE:  at least on Tim's WinXP Pro SP2 desktop box, while the last
      # 6 bytes returned by UuidCreateSequential are fixed, they don't appear
      # to bear any relationship to the MAC address of any network device
      # on the box.
      try:
          lib = ctypes.windll.rpcrt4
      except:
          lib = None
      _UuidCreate = getattr(lib, 'UuidCreateSequential',
                            getattr(lib, 'UuidCreate', None))
  except:
      pass
  
  def _unixdll_getnode():
      """Get the hardware address on Unix using ctypes."""
      _buffer = ctypes.create_string_buffer(16)
      _uuid_generate_time(_buffer)
      return UUID(bytes=bytes_(_buffer.raw)).node
  
  def _windll_getnode():
      """Get the hardware address on Windows using ctypes."""
      _buffer = ctypes.create_string_buffer(16)
      if _UuidCreate(_buffer) == 0:
          return UUID(bytes=bytes_(_buffer.raw)).node
  
  def _random_getnode():
      """Get a random node ID, with eighth bit set as suggested by RFC 4122."""
      import random
      return random.randrange(0, 1<<48) | 0x010000000000
  
  _node = None
  
  def getnode():
      """Get the hardware address as a 48-bit positive integer.
  
      The first time this runs, it may launch a separate program, which could
      be quite slow.  If all attempts to obtain the hardware address fail, we
      choose a random 48-bit number with its eighth bit set to 1 as recommended
      in RFC 4122.
      """
  
      global _node
      if _node is not None:
          return _node
  
      import sys
      if sys.platform == 'win32':
          getters = [_windll_getnode, _netbios_getnode, _ipconfig_getnode]
      else:
          getters = [_unixdll_getnode, _ifconfig_getnode]
  
      for getter in getters + [_random_getnode]:
          try:
              _node = getter()
          except:
              continue
          if _node is not None:
              return _node
  
  _last_timestamp = None
  
  def uuid1(node=None, clock_seq=None):
      """Generate a UUID from a host ID, sequence number, and the current time.
      If 'node' is not given, getnode() is used to obtain the hardware
      address.  If 'clock_seq' is given, it is used as the sequence number;
      otherwise a random 14-bit sequence number is chosen."""
  
      # When the system provides a version-1 UUID generator, use it (but don't
      # use UuidCreate here because its UUIDs don't conform to RFC 4122).
      if _uuid_generate_time and node is clock_seq is None:
          _buffer = ctypes.create_string_buffer(16)
          _uuid_generate_time(_buffer)
          return UUID(bytes=bytes_(_buffer.raw))
  
      global _last_timestamp
      import time
      nanoseconds = int(time.time() * 1e9)
      # 0x01b21dd213814000 is the number of 100-ns intervals between the
      # UUID epoch 1582-10-15 00:00:00 and the Unix epoch 1970-01-01 00:00:00.
      timestamp = int(nanoseconds/100) + 0x01b21dd213814000
      if _last_timestamp is not None and timestamp <= _last_timestamp:
          timestamp = _last_timestamp + 1
      _last_timestamp = timestamp
      if clock_seq is None:
          import random
          clock_seq = random.randrange(1<<14) # instead of stable storage
      time_low = timestamp & 0xffffffff
      time_mid = (timestamp >> 32) & 0xffff
      time_hi_version = (timestamp >> 48) & 0x0fff
      clock_seq_low = clock_seq & 0xff
      clock_seq_hi_variant = (clock_seq >> 8) & 0x3f
      if node is None:
          node = getnode()
      return UUID(fields=(time_low, time_mid, time_hi_version,
                          clock_seq_hi_variant, clock_seq_low, node), version=1)
  
  def uuid3(namespace, name):
      """Generate a UUID from the MD5 hash of a namespace UUID and a name."""
      from hashlib import md5
      hash = md5(namespace.bytes + bytes(name, "utf-8")).digest()
      return UUID(bytes=hash[:16], version=3)
  
  def uuid4():
      """Generate a random UUID."""
  
      # When the system provides a version-4 UUID generator, use it.
      if _uuid_generate_random:
          _buffer = ctypes.create_string_buffer(16)
          _uuid_generate_random(_buffer)
          return UUID(bytes=bytes_(_buffer.raw))
  
      # Otherwise, get randomness from urandom or the 'random' module.
      try:
          import os
          return UUID(bytes=os.urandom(16), version=4)
      except:
          import random
          bytes = bytes_(random.randrange(256) for i in range(16))
          return UUID(bytes=bytes, version=4)
  
  def uuid5(namespace, name):
      """Generate a UUID from the SHA-1 hash of a namespace UUID and a name."""
      from hashlib import sha1
      hash = sha1(namespace.bytes + bytes(name, "utf-8")).digest()
      return UUID(bytes=hash[:16], version=5)
  
  # The following standard UUIDs are for use with uuid3() or uuid5().
  
  NAMESPACE_DNS = UUID('6ba7b810-9dad-11d1-80b4-00c04fd430c8')
  NAMESPACE_URL = UUID('6ba7b811-9dad-11d1-80b4-00c04fd430c8')
  NAMESPACE_OID = UUID('6ba7b812-9dad-11d1-80b4-00c04fd430c8')
  NAMESPACE_X500 = UUID('6ba7b814-9dad-11d1-80b4-00c04fd430c8')
  