Python convert string to uuid

Generate a UUID in Python

Python is a very popular, interpreted, dynamically typed, object-oriented programming language.

First released in 1991 by Guido van Rossum, Python makes use of indentation and whitespace to delimit different blocks of code. It is a general-purpose language and as such is used in many different contexts including (to name just a few) web applications and artificial intelligence.

How to Generate a UUID in Python

The Python language has built-in support for generating Version 1, 3, 4 and 5 UUIDs. Here’s an example of how you can create a Version 4 UUID in Python code.

import uuid 
 
myuuid = uuid.uuid4() 
 
print('Your UUID is: ' + str(myuuid)) 

Explanation

• On line #1, we import Python’s built-in uuid module.
• On line #3, we generate a new Version 4 UUID using the uuid module and store it in the variable, myuuid . This is an instance of Python’s UUID class, not a string.
• On line #5, we use Python’s function, str , to convert from the UUID object to a string.
• The output from line #5 will be something like:

Your UUID is: c303282d-f2e6-46ca-a04a-35d3d873712d

Python’s uuid module has a number of other functions, such as for generating other UUID versions (i.e. 1, 3, 4, and 5). An instance of the Python UUID class has a number of useful methods on it, such as for converting the UUID to bytes, or for converting to a 32 character string (i.e. normal UUID without the ‘-‘ characters).

Convert from a String to a UUID

Although it’s rare, in some circumstances you might need to convert from a string (like the one generated on line #5 above) or byte representation of a UUID back into an instance of UUID .

Python’s uuid module provides for this scenario with the constructor method, uuid.UUID . You can call this method like this:

import uuid 
 
myuuid = uuid.uuid4() 
myuuidStr = str(myuuid) 
 
sameMyUuid = uuid.UUID(myuuidStr) 
assert myuuid == sameMyUuid 

Explanation

• Line #3 generates a new Version 4 UUID.
• Line #4 converts the UUID instance into a string, using the str function.
• Line #6 converts the string representation of a UUID into a Python UUID instance ( sameMyUuid ) using the uuid.UUID() method. Note that this method accepts a number of different formats, including strings and bytes.
• Line #7 is included to show that the 2 UUID instances are equal.

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21.20. 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 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:

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.

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 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. 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.

21.20.1. 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') 

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