2.5 版新增。
此模块提供不可变 UUID 对象 ( UUID 类) 和函数 uuid1() , uuid3() , uuid4() , uuid5() 用于生成第 1、3、4 和 5 版的 UUID 作为指定在 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.
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 字段 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 , 字段 ，或 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 , 字段 ，或 int .
UUID 实例拥有这些只读属性：
The UUID as a 16-byte string (containing the six integer fields in big-endian byte order).
The UUID as a 16-byte string (with time_low , time_mid ，和 time_hi_version in little-endian byte order).
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 |
The UUID as a 32-character hexadecimal string.
The UUID as a 128-bit integer.
The UUID as a URN as specified in RFC 4122.
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 ，或 RESERVED_FUTURE .
The UUID version number (1 through 5, meaningful only when the variant is RFC_4122 ).
The uuid 模块定义了下列函数：
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.
Generate a UUID from a host ID, sequence number, and the current time. If node 未给定， 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() .
When this namespace is specified, the name string is a fully-qualified domain name.
When this namespace is specified, the name string is a URL.
When this namespace is specified, the name string is an ISO OID.
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 属性：
Reserved for NCS compatibility.
Reserved for Microsoft compatibility.
Reserved for future definition.
另请参阅
Here are some examples of typical usage of the uuid 模块：
>>> 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 '\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')
