cidrtrie is a simplistic implementation of a prefix tree and a library for classifying IP addresses based on prefix matching. Unlike other implementations (such as py-radix), this is pure-Python and aims to be as simple as possible.
This implementation offers asymptotic performance improvement for problems that look like Internet routing.
bench.py contains a simple and used-elsewhere O(n) implementation ("NaiveCidrClassifier) of this same functionalify. Some sample numbers for inserting 100,000 cidrs into the tree and then looking up 10,000 IPs on a 3GHz Intel i7-4578U:
insert CidrClassifier 5.16s
insert NaiveCidrClassifier 0.11s
lookup CidrClassifier 0.25s
lookup NaiveCidrClassifier 92.11s
An example use case would be to efficiently map IP addresses (from logs or some other source) to the originating network (and, eventually, to the owner) without using a commercial library like MaxMind or bringing in any native-code dependencies.