Skip to main content

Python library that provides an implementation of the ULID Specification

Project description

py-ulid - A ULID Implementation in Python

ulid logo

Documentation Status

The py-ulid library is a minimal and self-contained implementation of the ULID (Universally Unique Lexicographically Sortable Identifier) specification in Python. For more information, please refer to the official specification.

UUID can be suboptimal for many uses-cases because:

  • It isn't the most character efficient way of encoding 128 bits of randomness
  • UUID v1/v2 is impractical in many environments, as it requires access to a unique, stable MAC address
  • UUID v3/v5 requires a unique seed and produces randomly distributed IDs, which can cause fragmentation in many data structures
  • UUID v4 provides no other information than randomness which can cause fragmentation in many data structures

Instead, herein is proposed ULID:

  • 128-bit compatibility with UUID
  • 1.21e+24 unique ULIDs per millisecond
  • Lexicographically sortable!
  • Canonically encoded as a 26 character string, as opposed to the 36 character UUID
  • Uses Crockford's base32 for better efficiency and readability (5 bits per character)
  • Case insensitive
  • No special characters (URL safe)
  • Monotonic sort order (correctly detects and handles the same millisecond)

Installation

You can install the py-ulid library from PyPi

pip install py-ulid

The py-ulid library can be used in any version of python >= 3.5 and does not require any additional packages or modules.

How to use

To generate a ULID, simple run the generate() function

from ulid import ULID

#Instantiate the ULID class
ulid = ULID()
ulid.generate()  #01BX5ZZKBKACTAV9WEVGEMMVRZ

Seeding Time

You can instantiate the instance of the ULID class with a seed time which will output the same string for the time component. This could be useful when migrating to ulid

from ulid import ULID

#Instantiate the ULID class
ulid = ULID(1469918176385)
ulid.generate()  #01ARYZ6S41TSV4RRFFQ69G5FAV

Monotonic ULIDs

from ulid import Monotonic

#Instantiate the Monotonic Class
ulid = Monotonic()

# Same timestamp when calls are made within the same
# millisecond and least-significant random bit is incremented by 1
ulid.generate()  #01DC8Y7RBV4RSXX0437Z1RQR11
ulid.generate()  #01DC8Y7RBV4RSXX0437Z1RQR12
ulid.generate()  #01DC8Y7RBV4RSXX0437Z1RQR13
ulid.generate()  #01DC8Y7RBV4RSXX0437Z1RQR14
ulid.generate()  #01DC8Y7RBV4RSXX0437Z1RQR15
ulid.generate()  #01DC8Y7RBV4RSXX0437Z1RQR16
ulid.generate()  #01DC8Y7RBV4RSXX0437Z1RQR17
ulid.generate()  #01DC8Y7RBV4RSXX0437Z1RQR18
ulid.generate()  #01DC8Y7RBV4RSXX0437Z1RQR19

Prior Art

Partly inspired by:

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Files for py-ulid, version 1.0.3
Filename, size File type Python version Upload date Hashes
Filename, size py-ulid-1.0.3.tar.gz (5.4 kB) File type Source Python version None Upload date Hashes View

Supported by

Pingdom Pingdom Monitoring Google Google Object Storage and Download Analytics Sentry Sentry Error logging AWS AWS Cloud computing DataDog DataDog Monitoring Fastly Fastly CDN DigiCert DigiCert EV certificate StatusPage StatusPage Status page