This project is a python implementation of the Go Lang library found here: https://github.com/rs/xid
I've included the ReadMe from that project here (with some modifications for python).
Package xid is a globally unique id generator library, ready to be used safely directly in your server code.
Xid is using Mongo Object ID algorithm to generate globally unique ids with a different serialization (base64) to make it shorter when transported as a string: https://docs.mongodb.org/manual/reference/object-id/
The binary representation of the id is compatible with Mongo 12 bytes Object IDs. The string representation is using base32 hex (w/o padding) for better space efficiency when stored in that form (20 bytes). The hex variant of base32 is used to retain the sortable property of the id.
Xid doesn't use base64 because case sensitivity and the 2 non alphanum chars may be an
issue when transported as a string between various systems. Base36 wasn't retained either
because 1/ it's not standard 2/ the resulting size is not predictable (not bit aligned)
and 3/ it would not remain sortable. To validate a base32 xid
, expect a 20 chars long,
all lowercase sequence of a
to v
letters and 0
to 9
numbers ([0-9a-v]{20}
).
UUIDs are 16 bytes (128 bits) and 36 chars as string representation. Twitter Snowflake ids are 8 bytes (64 bits) but require machine/data-center configuration and/or central generator servers. xid stands in between with 12 bytes (96 bits) and a more compact URL-safe string representation (20 chars). No configuration or central generator server is required so it can be used directly in server's code.
Name | Binary Size | String Size | Features |
---|---|---|---|
UUID | 16 bytes | 36 chars | configuration free, not sortable |
shortuuid | 16 bytes | 22 chars | configuration free, not sortable |
Snowflake | 8 bytes | up to 20 chars | needs machin/DC configuration, needs central server, sortable |
MongoID | 12 bytes | 24 chars | configuration free, sortable |
xid | 12 bytes | 20 chars | configuration free, sortable |
Features:
Best used with xlog's RequestIDHandler.
References:
easy_install python_xid
from xid import Xid
guid = Xid()
print guid.string()
// Output: 9m4e2mr0ui3e8a215n4g
Get xid
embedded info:
guid.machine()
guid.pid()
guid.time()
guid.counter()
All source code is licensed under the MIT License.