Pure Python splay tree nodule
A pure python splay tree class is provided. It is thoroughly unit tested, passes pylint, and is known to run on CPython 2.x, CPython 3.x, Pypy 2.2 and Jython 2.7b1.
This splay tree looks like a dictionary that’s always sorted by key. It also reorganizes itself on every get and put, to optimize subsequent operations on the same key. For this reason, splay trees are frequently used for caches.