Project: python-ulid

A ULID is a universally unique lexicographically sortable identifier. It is

• 128-bit compatible 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)

In general the structure of a ULID is as follows:

.. code-block:: text

01AN4Z07BY 79KA1307SR9X4MV3 |----------| |----------------| Timestamp Randomness 48bits 80bits

For more information have a look at the original specification <https://github.com/alizain/ulid#specification>_.

.. teaser-end

.. installation-begin

Installation

Use pip to install the library

.. code-block:: bash

$ pip install python-ulid

.. installation-end

.. usage-begin

Basic Usage

Create a new ULID object from the current timestamp

.. code-block:: pycon

from ulid import ULID ULID() ULID(01E75HZVW36EAZKMF1W7XNMSB4)

or use one of the named constructors

.. code-block:: pycon

import time, datetime ULID.from_timestamp(time.time()) ULID(01E75J1MKKWMGG0N5MBHFMRC84) ULID.from_datetime(datetime.datetime.now()) ULID(01E75J2XBK390V2XRH44EHC10X)

There are several options for encoding the ULID object (e.g. string, hex, int), as well as to access the timestamp attribute in different formats:

.. code-block:: pycon

str(ulid) '01BTGNYV6HRNK8K8VKZASZCFPE' ulid.hex '015ea15f6cd1c56689a373fab3f63ece' ulid.timestamp 1505945939.153 ulid.datetime datetime.datetime(2017, 9, 20, 22, 18, 59, 153000, tzinfo=datetime.timezone.utc) ulid.to_uuid() UUID('015ea15f-6cd1-c566-89a3-73fab3f63ece')

.. usage-end

.. cli-begin

Command line interface

The package comes with a CLI interface that can be invoked either by the script name ulid or as python module python -m ulid. The CLI allows you to generate, inspect and convert ULIDs, e.g.

.. code-block:: bash

$ ulid build 01HASFKBN8SKZTSVVS03K5AMMS

$ ulid build --from-datetime=2023-09-23T10:20:30 01HB0J0F5GCKEXNSWVAD5PEAC1

$ ulid show 01HASFKBN8SKZTSVVS03K5AMMS ULID: 01HASFKBN8SKZTSVVS03K5AMMS Hex: 018ab2f9aea8ccffacef7900e6555299 Int: 2049395013039097460549394558635823769 Timestamp: 1695219822.248 Datetime: 2023-09-20 14:23:42.248000+00:00

The special character - allows to read values from stdin so that they can be piped. E.g.

.. code-block:: bash

$ echo 01HASFKBN8SKZTSVVS03K5AMMS | ulid show --uuid - 018ab2f9-aea8-4cff-acef-7900e6555299

$ date --iso-8601 | python -m ulid build --from-datetime - 01HAT9PVR02T3S13XB48S7GEHE

.. cli-end

Other implementations

• ahawker/ulid <https://github.com/ahawker/ulid>_
• valohai/ulid2 <https://github.com/valohai/ulid2>_
• mdipierro/ulid <https://github.com/mdipierro/ulid>_