### 导航 - [索引](../genindex.xhtml "总目录") - [模块](../py-modindex.xhtml "Python 模块索引") | - [下一页](socketserver.xhtml "socketserver --- A framework for network servers") | - [上一页](telnetlib.xhtml "telnetlib --- Telnet client") | -  - [Python](https://www.python.org/) » - zh\_CN 3.7.3 [文档](../index.xhtml) » - [Python 标准库](index.xhtml) » - [互联网协议和支持](internet.xhtml) » - $('.inline-search').show(0); | # [`uuid`](#module-uuid "uuid: UUID objects (universally unique identifiers) according to RFC 4122") --- UUID objects according to [**RFC 4122**](https://tools.ietf.org/html/rfc4122.html) \[https://tools.ietf.org/html/rfc4122.html\] **Source code:** [Lib/uuid.py](https://github.com/python/cpython/tree/3.7/Lib/uuid.py) \[https://github.com/python/cpython/tree/3.7/Lib/uuid.py\] - - - - - - This module provides immutable [`UUID`](#uuid.UUID "uuid.UUID") objects (the [`UUID`](#uuid.UUID "uuid.UUID") class) and the functions [`uuid1()`](#uuid.uuid1 "uuid.uuid1"), [`uuid3()`](#uuid.uuid3 "uuid.uuid3"), [`uuid4()`](#uuid.uuid4 "uuid.uuid4"), [`uuid5()`](#uuid.uuid5 "uuid.uuid5") for generating version 1, 3, 4, and 5 UUIDs as specified in [**RFC 4122**](https://tools.ietf.org/html/rfc4122.html) \[https://tools.ietf.org/html/rfc4122.html\]. If all you want is a unique ID, you should probably call [`uuid1()`](#uuid.uuid1 "uuid.uuid1") or [`uuid4()`](#uuid.uuid4 "uuid.uuid4"). Note that [`uuid1()`](#uuid.uuid1 "uuid.uuid1") may compromise privacy since it creates a UUID containing the computer's network address. [`uuid4()`](#uuid.uuid4 "uuid.uuid4") creates a random UUID. Depending on support from the underlying platform, [`uuid1()`](#uuid.uuid1 "uuid.uuid1") may or may not return a "safe" UUID. A safe UUID is one which is generated using synchronization methods that ensure no two processes can obtain the same UUID. All instances of [`UUID`](#uuid.UUID "uuid.UUID") have an `is_safe` attribute which relays any information about the UUID's safety, using this enumeration: *class* `uuid.``SafeUUID`3\.7 新版功能. `safe`The UUID was generated by the platform in a multiprocessing-safe way. `unsafe`The UUID was not generated in a multiprocessing-safe way. `unknown`The platform does not provide information on whether the UUID was generated safely or not. *class* `uuid.``UUID`(*hex=None*, *bytes=None*, *bytes\_le=None*, *fields=None*, *int=None*, *version=None*, *\**, *is\_safe=SafeUUID.unknown*)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*, 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**](https://tools.ietf.org/html/rfc4122.html) \[https://tools.ietf.org/html/rfc4122.html\], overriding bits in the given *hex*, *bytes*, *bytes\_le*, *fields*, or *int*. Comparison of UUID objects are made by way of comparing their [`UUID.int`](#uuid.UUID.int "uuid.UUID.int") attributes. Comparison with a non-UUID object raises a [`TypeError`](exceptions.xhtml#TypeError "TypeError"). `str(uuid)` returns a string in the form `12345678-1234-5678-1234-567812345678` where the 32 hexadecimal digits represent the UUID. [`UUID`](#uuid.UUID "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*, 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 意义 `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`](time.xhtml#module-time "time: Time access and conversions.") 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**](https://tools.ietf.org/html/rfc4122.html) \[https://tools.ietf.org/html/rfc4122.html\]. `UUID.``variant`The UUID variant, which determines the internal layout of the UUID. This will be one of the constants [`RESERVED_NCS`](#uuid.RESERVED_NCS "uuid.RESERVED_NCS"), [`RFC_4122`](#uuid.RFC_4122 "uuid.RFC_4122"), [`RESERVED_MICROSOFT`](#uuid.RESERVED_MICROSOFT "uuid.RESERVED_MICROSOFT"), or [`RESERVED_FUTURE`](#uuid.RESERVED_FUTURE "uuid.RESERVED_FUTURE"). `UUID.``version`The UUID version number (1 through 5, meaningful only when the variant is [`RFC_4122`](#uuid.RFC_4122 "uuid.RFC_4122")). `UUID.``is_safe`An enumeration of [`SafeUUID`](#uuid.SafeUUID "uuid.SafeUUID") which indicates whether the platform generated the UUID in a multiprocessing-safe way. 3\.7 新版功能. The [`uuid`](#module-uuid "uuid: UUID objects (universally unique identifiers) according to RFC 4122") 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 the multicast bit (least significant bit of the first octet) set to 1 as recommended in [**RFC 4122**](https://tools.ietf.org/html/rfc4122.html) \[https://tools.ietf.org/html/rfc4122.html\]. "Hardware address" means the MAC address of a network interface. On a machine with multiple network interfaces, universally administered MAC addresses (i.e. where the second least significant bit of the first octet is *unset*) will be preferred over locally administered MAC addresses, but with no other ordering guarantees. 在 3.7 版更改: Universally administered MAC addresses are preferred over locally administered MAC addresses, since the former are guaranteed to be globally unique, while the latter are not. `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()`](#uuid.getnode "uuid.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-uuid "uuid: UUID objects (universally unique identifiers) according to RFC 4122") module defines the following namespace identifiers for use with [`uuid3()`](#uuid.uuid3 "uuid.uuid3") or [`uuid5()`](#uuid.uuid5 "uuid.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-uuid "uuid: UUID objects (universally unique identifiers) according to RFC 4122") 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**](https://tools.ietf.org/html/rfc4122.html) \[https://tools.ietf.org/html/rfc4122.html\]. `uuid.``RESERVED_MICROSOFT`Reserved for Microsoft compatibility. `uuid.``RESERVED_FUTURE`Reserved for future definition. 参见 [**RFC 4122**](https://tools.ietf.org/html/rfc4122.html) \[https://tools.ietf.org/html/rfc4122.html\] - A Universally Unique IDentifier (UUID) URN NamespaceThis specification defines a Uniform Resource Name namespace for UUIDs, the internal format of UUIDs, and methods of generating UUIDs. ## 示例 Here are some examples of typical usage of the [`uuid`](#module-uuid "uuid: UUID objects (universally unique identifiers) according to RFC 4122") 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 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') ``` ### 导航 - [索引](../genindex.xhtml "总目录") - [模块](../py-modindex.xhtml "Python 模块索引") | - [下一页](socketserver.xhtml "socketserver --- A framework for network servers") | - [上一页](telnetlib.xhtml "telnetlib --- Telnet client") | -  - [Python](https://www.python.org/) » - zh\_CN 3.7.3 [文档](../index.xhtml) » - [Python 标准库](index.xhtml) » - [互联网协议和支持](internet.xhtml) » - $('.inline-search').show(0); | © [版权所有](../copyright.xhtml) 2001-2019, Python Software Foundation. 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