def test_oov(self):
tx = Trie()
tx.add('')
tx.add('a')
ty = Trie()
ty.add('b')
ty.add('')
ep = EditProbability(Alphabet(tx), Alphabet(ty))
self.assertAlmostEqual(ep.score('a', 'bc'), 0)
def test_score(self):
tx = Trie()
tx.add('')
tx.add('a')
ty = Trie()
ty.add('b')
ty.add('c')
ty.add('bc')
ty.add('')
ep = EditProbability(Alphabet(tx), Alphabet(ty))
ep.probs['a', ''] = 0.5
ep.probs['', 'b'] = 0.4
ep.probs['', 'c'] = 0.3
ep.probs['a', 'b'] = 0.2
ep.probs['', 'bc'] = 0.1
ep.probs['a', 'bc'] = 0.0
ep.probs['a', 'c'] = 0.0
self.assertAlmostEqual(ep.score('a', 'bc'), 0.34)