uuid — UUID objects according to RFC 4122¶
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.
Depending on support from the underlying platform, 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 have an is_safe attribute which relays any information about the UUID’s safety, using this enumeration:
The UUID was generated by the platform in a multiprocessing-safe way.
The UUID was not generated in a multiprocessing-safe way.
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('') 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, 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 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:
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, and 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:
the first 32 bits of the UUID
the next 16 bits of the UUID
the next 16 bits of the UUID
the next 8 bits of the UUID
the next 8 bits of the UUID
the last 48 bits of the UUID
the 14-bit sequence number
The UUID as a 32-character lowercase 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 constants RESERVED_NCS , RFC_4122 , RESERVED_MICROSOFT , or RESERVED_FUTURE .
The UUID version number (1 through 5, meaningful only when the variant is RFC_4122 ).
An enumeration of SafeUUID which indicates whether the platform generated the UUID in a multiprocessing-safe way.
The uuid module defines the following functions:
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. “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.
Changed in version 3.7: 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.
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. 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() .
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 attribute:
Reserved for NCS compatibility.
Specifies the UUID layout given in RFC 4122.
Reserved for Microsoft compatibility.
Reserved for future definition.
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.
Example¶
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('') >>> # 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')
ShawnMilo / validate_uuid4.py
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| from uuid import UUID |
| def validate_uuid4 ( uuid_string ): |
| «»» |
| Validate that a UUID string is in |
| fact a valid uuid4. |
| Happily, the uuid module does the actual |
| checking for us. |
| It is vital that the ‘version’ kwarg be passed |
| to the UUID() call, otherwise any 32-character |
| hex string is considered valid. |
| «»» |
| try : |
| val = UUID ( uuid_string , version = 4 ) |
| except ValueError : |
| # If it’s a value error, then the string |
| # is not a valid hex code for a UUID. |
| return False |
| # If the uuid_string is a valid hex code, |
| # but an invalid uuid4, |
| # the UUID.__init__ will convert it to a |
| # valid uuid4. This is bad for validation purposes. |
| return val . hex == uuid_string |
| if __name__ == ‘__main__’ : |
| # Valid uuid, generated by uuid4(): |
| x = ’89eb35868a8247a4a911758a62601cf7′ |
| print validate_uuid4 ( x ) |
| # Same as above, except for the 17th charecter |
| # which is a valid hex string, but not a valid uuid4. |
| x = ’89eb35868a8247a4c911758a62601cf7′ |
| print validate_uuid4 ( x ) |
Как проверить UUID версии 4 в python?
Я должен проверить UUID версии 4, который является общим именем в сертификате. Имеется ли какой-либо встроенный Python для проверки правильности UUID prsesnt в сертификате или нет и проверки его версии? Если нет, то как сравнить UUID версии 4
1 ответ
Как говорит Джакомо Альзетта, UUID можно сравнивать как любой другой объект, используя == , UUID Конструктор нормализует строки, поэтому не имеет значения, имеет ли UUID нестандартную форму.
import uuid uuid.UUID('302a4299-736e-4ef3-84fc-a9f400e84b24') == uuid.UUID('302a4299-736e-4ef3-84fc-a9f400e84b24') # => True uuid.UUID('302a4299736e4ef384fca9f400e84b24') == uuid.UUID('') # => True Сравнение строк будет сравнивать литеральные строки, которые могут соответствовать или не соответствовать UUID:
'302a4299-736e-4ef3-84fc-a9f400e84b24' == '302a4299-736e-4ef3-84fc-a9f400e84b24' # => True '302a4299736e4ef384fca9f400e84b24' == '' # => False Вы можете конвертировать UUID в строки, используя str(x) или строки в объекты UUID, используя uuid.UUID(x) как показано выше. Обратите внимание, что вы не можете сравнивать строки с UUID, только строки со строками и UUID с UUID.
Если это действительно выдает ошибку, независимо от того, находится ли строка UUID в ее канонической форме, вы можете попытаться преобразовать ее в объект UUID и обратно в строку (что даст вам каноническую форму), и сравнить ее с оригинальной:
x = '302a4299-736e-4ef3-84fc-a9f400e84b24' str(uuid.UUID(x)) == x # => True x = '302a4299736e4ef384fca9f400e84b24' str(uuid.UUID(x)) == x # => False Однако вам действительно не важно, является ли строка UUID канонической — до тех пор, пока она может быть распознана как строка UUID, она должна быть достаточно хорошей. Если это не может.
uuid.UUID("foo") # => ValueError: badly formed hexadecimal UUID string Если вам нужно знать версию UUID, она находится прямо в UUID API:
uuid.UUID('302a4299-736e-4ef3-84fc-a9f400e84b24').version # => 4