uuid module¶

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’x00x01x02x03x04x05x06x07x08tnx0bx0crx0ex0f’

# make a UUID from a 16-byte string >>> uuid.UUID(bytes=x.bytes) UUID(‘00010203-0405-0607-0809-0a0b0c0d0e0f’)

class uuid.SafeUUID(value)¶

Bases: enum.Enum

An enumeration.

safe = 0¶

unknown = None¶

unsafe = -1¶

class uuid.UUID(hex=None, bytes=None, bytes_le=None, fields=None, int=None, version=None, *, is_safe=SafeUUID.unknown)¶

Bases: 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)

is_safe An enum indicating whether the UUID has been generated in
a way that is safe for multiprocessing applications, via uuid_generate_time_safe(3).

property bytes¶

property bytes_le¶

property clock_seq¶

property clock_seq_hi_variant¶

property clock_seq_low¶

property fields¶

property hex¶

int¶

is_safe¶

property node¶

property time¶

property time_hi_version¶

property time_low¶

property time_mid¶

property urn¶

property variant¶

property version¶

uuid.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.

uuid.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.

uuid.uuid3(namespace, name)¶: Generate a UUID from the MD5 hash of a namespace UUID and a name.

uuid.uuid4()¶: Generate a random UUID.

uuid.uuid5(namespace, name)¶: Generate a UUID from the SHA-1 hash of a namespace UUID and a name.