Simple bloom filter, just for learning. Need bitarray support

bloom_filter.py

# -*- coding: utf-8 -*-

import os
from hashlib import md5
from bitarray import bitarray


class BloomFilter(object):

    def __init__(self, count, size, hash_count=8):
        self.count = count
        self.size = size
        self.bits_length = count * size
        self.bits = bitarray(self.bits_length)
        self.bits.setall(0)
        self._seeds = [os.urandom(8) for x in xrange(hash_count)]

    def add(self, v):
        for seed in self._seeds:
            pos = self._alloc(self._hash(v, seed))
            self.bits[pos] = 1

    def check(self, v):
        for seed in self._seeds:
            pos = self._alloc(self._hash(v, seed))
            if not self.bits[pos]:
                return False
        return True

    def _hash(self, v, seed):
        m = md5(seed)
        m.update(v)
        return int(m.hexdigest(), 16)

    def _alloc(self, hash):
        return hash % self.bits_length

    def _print(self):
        print self.bits