21.20. uuid — UUID 对象根据 RFC 4122 ¶

源代码： Lib/uuid.py

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() 。注意， uuid1() may compromise privacy since it creates a UUID containing the computer’s network address. uuid4() creates a random UUID.

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

Create a UUID from either a string of 32 hexadecimal digits, a string of 16 bytes in big-endian order 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=b'\x12\x34\x56\x78'*4)
UUID(bytes_le=b'\x78\x56\x34\x12\x34\x12\x78\x56' +
              b'\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 ，或 int must be given. 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 ，或 int .

Comparison of UUID objects are made by way of comparing their UUID.int attributes. Comparison with a non-UUID object raises a TypeError .

str(uuid) returns a string in the form 12345678-1234-5678-1234-567812345678 where the 32 hexadecimal digits represent the UUID.

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 ，和 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:

字段	含义
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 constants RESERVED_NCS , RFC_4122 , RESERVED_MICROSOFT ，或 RESERVED_FUTURE .

UUID. version ¶

The UUID version number (1 through 5, meaningful only when the variant is RFC_4122 ).

uuid 模块定义了下列函数：

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=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 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).

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.

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.

>>> 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
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')
								

内容表

• 21.20. uuid — UUID 对象根据 RFC 4122
  • 21.20.1. 范例

上一话题

21.19. telnetlib — Telnet 客户端

下一话题

21.21. socketserver — 网络服务器框架