How to create a GUID/UUID in Python

Question

How do I create a GUID in Python that is platform independent? I hear there is a method using ActivePython on Windows but it's Windows only because it uses COM. Is there a method using plain Python?

Solution 1

The uuid 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.

UUID versions 6 and 7 - new Universally Unique Identifier (UUID) formats for use in modern applications and databases (draft) rfc - are available from https://pypi.org/project/uuid6/

Docs:

• Python 2
• Python 3

Examples (for both Python 2 and 3):

>>> import uuid

>>> # make a random UUID
>>> uuid.uuid4()
UUID('bd65600d-8669-4903-8a14-af88203add38')

>>> # Convert a UUID to a string of hex digits in standard form
>>> str(uuid.uuid4())
'f50ec0b7-f960-400d-91f0-c42a6d44e3d0'

>>> # Convert a UUID to a 32-character hexadecimal string
>>> uuid.uuid4().hex
'9fe2c4e93f654fdbb24c02b15259716c'

Solution 2

If you're using Python 2.5 or later, the uuid module is already included with the Python standard distribution.

Ex:

>>> import uuid
>>> uuid.uuid4()
UUID('5361a11b-615c-42bf-9bdb-e2c3790ada14')

Solution 3

Copied from : https://docs.python.org/3/library/uuid.html (Since the links posted were not active and they keep updating)

>>> 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')

Solution 4

I use GUIDs as random keys for database type operations.

The hexadecimal form, with the dashes and extra characters seem unnecessarily long to me. But I also like that strings representing hexadecimal numbers are very safe in that they do not contain characters that can cause problems in some situations such as '+','=', etc..

Instead of hexadecimal, I use a url-safe base64 string. The following does not conform to any UUID/GUID spec though (other than having the required amount of randomness).

import base64
import uuid

# get a UUID - URL safe, Base64
def get_a_uuid():
    r_uuid = base64.urlsafe_b64encode(uuid.uuid4().bytes)
    return r_uuid.replace('=', '')

Solution 5

If you need to pass UUID for a primary key for your model or unique field then below code returns the UUID object -

 import uuid
 uuid.uuid4()

If you need to pass UUID as a parameter for URL you can do like below code -

import uuid
str(uuid.uuid4())

If you want the hex value for a UUID you can do the below one -

import uuid    
uuid.uuid4().hex

View more solutions

Comments

[Sridhar Ratnakumar]

docs.activestate.com/activepython/2.6/python/library/uuid.ht‌​ml

[david.barkhuizen]

For the love of all that is sacred, it's a UUID - Universal Unique ID en.wikipedia.org/wiki/Universally_unique_identifier - its just that unfortunately MS has preferrred GUID.

[Ctrl-C]

Here's one liner for you: python -c 'import uuid; print(uuid.uuid4())'

[duhaime]

I think GUID makes more sense than UUID, as <i>global</i> means global within some namespace, while <i>universal</i> seems to claim true universal uniqueness. In any event we all know what we're talking about here.

[Stavros Korokithakis]

Also, have a look at the shortuuid module I wrote, as it allows you to generate shorter, readable UUIDs: github.com/stochastic-technologies/shortuuid

[Jay Patel]

@StavrosKorokithakis: have you written shortuuid module for Python 3.x by any chance?

[Stavros Korokithakis]

@JayPatel Does shortuuid not work for Python 3? If not, please file a bug.

[Kevin]

What's the difference between uuid4().hex and str(uuid4())?

[stuartd]

Well, as you can see above, str(uuid4()) returns a string representation of the UUID with the dashes included, while uuid4().hex returns "The UUID as a 32-character hexadecimal string"

[ShadowRanger]

If you're not going to bother using it in any UUID contexts, you may as well just use random.getrandbits(128).to_bytes(16, 'little') or (for crypto randomness) os.urandom(16) and get a full 128 bits of random (UUIDv4 uses 6-7 bits on version info). Or use only 15 bytes (losing 1-2 bits of random vs. UUIDv4) and avoid the need to trim off = signs while also reducing the encoded size to 20 bytes (from 24, trimmed to 22), as any multiple of 3 bytes encodes to #bytes / 3 * 4 base64 characters with no padding required.

[miguelr]

UUIDs are standard, and not variable in length. Generating a random string in a configurable way can be useful in some situations, but not in this context. You may check en.wikipedia.org/wiki/Universally_unique_identifier for definition.

[Chris Dutrow]

@ShadowRanger Yeah thats basically the idea. 128 random bits, as short as conveniently possible, while also being URL safe. Ideally it would only use upper and lower case letters and then numbers. So I guess a base-62 string.

[Sylvain Gantois]

Better avoid this one or you might run into compatibility issues (these are not standard GUIDs)

[Mark Kortink]

When i use your function i get a type error from the return statement expecting a bytes-like object. It can be fixed with return str(r_uuid).replace('=','').

[sox with Monica]

This seems completely unrelated to the question, which is about UUIDs.

[regretoverflow]

Also, not even remotely guaranteed to be unique. It may be random, but not unique.

[Austin Heller]

@regretoverflow No GUIDs are ever unique, simply so massive that a collision is extremely unlikely.

[user2555515]

GUID is a string representation of a very long number so 'LxoYNyXe...' does not cut in.