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 class uuid.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=’x12x34x56x78’*4) UUID(bytes_le=’x78x56x34x12x34x12x78x56’ +
‘x12x34x56x78x12x34x56x78’)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:
UUID.bytes
The UUID as a 16-byte string (containing the six integer fields in big-endian byte order).
UUID.bytes_le
The UUID as a 16-byte string (with time_low, time_mid, and time_hi_version in little-endian byte order).
UUID.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
UUID.hex
The UUID as a 32-character hexadecimal string.
UUID.int
The UUID as a 128-bit integer.
UUID.urn
The UUID as a URN as specified in RFC 4122.
UUID.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.
UUID.version
The UUID version number (1 through 5, meaningful only when the variant is RFC_4122).
The uuid module defines the following functions:
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. “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.
uuid.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.
uuid.uuid3(namespace, name)
Generate a UUID based on the MD5 hash of a namespace identifier (which is a UUID) and a name (which is a string).
uuid.uuid4()
Generate a random UUID.
uuid.uuid5(namespace, name)
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().
uuid.NAMESPACE_DNS
When this namespace is specified, the name string is a fully- qualified domain name.
uuid.NAMESPACE_URL
When this namespace is specified, the name string is a URL.
uuid.NAMESPACE_OID
When this namespace is specified, the name string is an ISO OID.
uuid.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:
uuid.RESERVED_NCS
Reserved for NCS compatibility.
uuid.RFC_4122
Specifies the UUID layout given in RFC 4122.
uuid.RESERVED_MICROSOFT
Reserved for Microsoft compatibility.
uuid.RESERVED_FUTURE
Reserved for future definition.
See also:
- RFC 4122 - A Universally Unique IDentifier (UUID) URN Namespace
- This specification defines a Uniform Resource Name namespace for UUIDs, the internal format of UUIDs, and methods of generating UUIDs.
Here are some examples of typical usage of the uuid module:
>>> import uuid# make a UUID based on the host ID and current time >>> uuid.uuid1() 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() 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 ‘x00x01x02x03x04x05x06x07x08tnx0bx0crx0ex0f’
# make a UUID from a 16-byte string >>> uuid.UUID(bytes=x.bytes) UUID(‘00010203-0405-0607-0809-0a0b0c0d0e0f’)