Python library that provides an implementation of the ULID Specification
py-ulid - A ULID Implementation in Python
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)
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
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
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
Partly inspired by:
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