bloom-filter

This bloom filter implementation:
1) Has a constructor that accepts a maximum intended size and maximum appropriate error (false positive) rate, and
derives the fiddly bits from that; most bloom filter modules ask the enduser to specify the fiddly bits themselves.
2) Has a nice test suite, including checks for error rate.
3) Is in pure Python that'll run on CPython 2.x, CPython 3.x, PyPy or Jython.
4) Has a pair of simple, fast hash functions that give a good error rate - they're better than many of the alternatives,
They're not Mumur or Jenkins, but the tests confirm that they're working well.
5) Passes pylint and pep8.
6) Supports adding elements, testing for membership, and'ing sets and or'ing sets.

The code is derived from http://code.activestate.com/recipes/577686-bloom-filter/ and inherits that code's license.

For more about Bloom Filters:
http://en.wikipedia.org/wiki/Bloom_filter
http://spyced.blogspot.com/2009/01/all-you-ever-wanted-to-know-about.html