UUID05 - compact human-readable almost unique identifiers for temporary objects in small non-synchronizing distributed systems. Inspired by nanoid and mktemp utility.

Well, it's not really unique (that's why 0.5) and collisions are possible but probability is low and it's probably acceptable.

The library have zero dependencies (well, you need python3 and pip) and provides you with UUID05 class based on int with two additional methods:

• make() - sort of constructor.
• as_b64() -> str - alternative compact representation.

Examples below explain how it works:

TTL (seconds)	Workers	Worker ID	Example value	Max value	.as_b64(max_value)
(hour) 3600	2	1	9589	132400	AgUw
3600	4	2	29589	332400	BRJw
3600	10	4	49589	932400	Djow
3600	16	1	195893	15356400	6lHw
3600	32	11	1195893	31356400	Ad518A
3600	256	53	539589397	25535996400	BfIQYfA
(2 days) 172800	2	1	1449589	11555200	sFGA
172800	4	2	21449589	31555200	AeF-gA
172800	10	4	41449589	91555200	BXUFgA
172800	16	4	414495893	1517107200	Wm04AA
172800	32	14	1414495893	3117107200	uctIAA
172800	256	179	1791449589397	2551727827200	AlIe1KkA

Installing

pip3 install uuid05

Using

from uuid05 import UUID05

# basic usage
uid = UUID05.make()
suffix: str = uid.as_b64()
object_name: str = f'autotest_object_{suffix}'

# .make() may be parametrized by workers: int, ttl: int, precision: int
# defaults are: workers=10, ttl=2 days, precision=1
uid: int = UUID05.make(workers=16, ttl=86400, precision=6)  # 1419554951415
uid.as_b64()  # 'AUqEXzNy'

# you may also want to just shorten your existing integer identifiers.
suffix: str = UUID05(123123123123).as_b64()
assert suffix == 'HKq1w7M'

# How to get maximum UUID value/length with given params?
max_value = UUID05.max_value(machines=16, ttl=86400, precision=6)  # 1586399913600
len(str(max_value)) == 13
len(max_value.as_b64()) == 8  # AXFczaaA
len(f'autotest_object_{max_value.as_b64()}') == 23  # autotest_object_AXFczaaA

It can be also used as an utility from command-line:

$ uuid05
61503153
$ uuid05 -w 2
1503125
$ uuid05 -t 3600 -w 2
27091
$ uuid05 -b -t 3600 -w 2
aZ8
$ uuid05 -b -w 2
FvN2
$ uuid05 -b
AxHktA
$ uuid05 -b -a '_-' -w 64
eB_5Yg
$ uuid05 --help

Where UUID05 is useful

In E2E/UI-testing. It's slow, and sometimes you need to check a data created by tests after run.

Or, more generally, in staging environments where you aren't sure that your testing system will delete data after runs, but the tested system is aware of such a data and deletes it after some time. There's also be multiple testing systems instances running simultaneously, and you don't want them to affect each other.

You also may want identifiers to be more or less rememberable for at least 10-15 seconds while you switching tabs.

Oh, and you don't want to synchronize workers via network. Otherwise Redis, Memcached or another database with a single INCRementing counter would do the trick.

When UUID05 is useless

• If your system isn't distributed, local counter in memory or file will work better.
• If your objects are persistent, you'd better use py-nanoid.
• If you need to generate multiple UIDs for multiple object really quick:
  • generate one and reuse it, using a semantic or loop variable as a suffix;
  • well, there's a simple collision preventing mechanism, allowing small "bursts" of loops;
    • If you seek for performance, disable it (uuid05.disable_cache = True) to win ~32% time.
  • pass precision argument to uuid05(). It scales automatically with worker count, but if there are less than 16 workers, default is 1 which means 1 uuid per 0.1 second, usually it's enough.
    • precision=3 argument will use milliseconds.
    • precision=6 for microseconds.
  • if precision=6 is not enough, stop trying to make your identifier compact.
• If you believe that semi-persistent data is a testing antipattern, and it should be cleared by the testing system before or after each run.

Benchmarks

Function	CPU Frequency (GHz)	Collision prevening mechanism enabled	Mean time, ns
UUID05.make()	3.8GHz	True	868
UUID05.make()	3.8GHz	False	1300
uuid.uuid4()	3.8GHz	n/a	1500
UUID05.make()	4.7GHz	True	779
UUID05.make()	4.7GHz	False	1070
UUID05(1333).as_b64()	3.8GHz	n/a	596
str(uuid.UUID)	3.8GHz	n/a	570

Development

• Tests are doctests and may be run by pytest.
• Benchmarks - use %timeit in ipython
• Documentation - look at code, it's just two files.
• Build - python3 -m build --sdist --wheel.
• Release twine check dist/uuid05-<version>* && twine upload dist/uuid05-<version>*.
• Design - UUID05 class doesn't try to copy uuid module methods, properties and behavior. Speed also isn't a goal.