New in version 2.5.
This module provides immutable UUID objects (the UUID class)
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.
class UUID( |
[hex[, bytes[,
bytes_le[, fields[, int[, version]]]]]]) |
-
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 number set according to
RFC 4122, overriding bits in the given hex, bytes,
bytes_le, fields, or int.
UUID instances 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:
Field |
Meaning |
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, which determines the internal layout of the UUID.
This will be one of the integer 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).
The uuid module defines the following functions:
-
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. "Hardware
address" means the MAC address of a network interface, and on a machine
with multiple network interfaces the MAC address of any one of them may
be returned.
uuid1( |
[node[, clock_seq]]) |
-
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.
-
Generate a UUID based on the MD5 hash
of a namespace identifier (which is a UUID) and a name (which is a string).
-
Generate a random UUID.
-
Generate a UUID based on the SHA-1 hash
of a namespace identifier (which is a UUID) and a name (which is a string).
The uuid module defines the following namespace identifiers
for use with uuid3() or uuid5().
- NAMESPACE_DNS
-
When this namespace is specified,
the name string is a fully-qualified domain name.
- NAMESPACE_URL
-
When this namespace is specified,
the name string is a URL.
- NAMESPACE_OID
-
When this namespace is specified,
the name string is an ISO OID.
- NAMESPACE_X500
-
When this namespace is specified,
the name string is an X.500 DN in DER or a text output format.
The uuid module defines the following constants
for the possible values of the variant attribute:
- RESERVED_NCS
-
Reserved for NCS compatibility.
- RFC_4122
-
Specifies the UUID layout given in RFC 4122.
- RESERVED_MICROSOFT
-
Reserved for Microsoft compatibility.
- RESERVED_FUTURE
-
Reserved for future definition.
Release 2.5.2, documentation updated on 21st February, 2008.
See About this document... for information on suggesting changes.
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