How to use the simpleai.machine_learning.metrics.OnlineEntropy function in simpleai

def test_full_gain(self):
        target = lambda x: x % 7
        gain = OnlineInformationGain(target, target)
        entropy = OnlineEntropy(target)
        for i in xrange(50):
            gain.add(i)
            entropy.add(i)
        self.assertEqual(gain.get_gain(), entropy.get_entropy())
        self.assertGreaterEqual(gain.get_gain(), 0)

def test_valid_values(self):
        entropy = OnlineEntropy(lambda x: x % 10)
        for i in xrange(150):
            entropy.add(i)
        self.assertGreaterEqual(entropy.get_entropy(), 0.0)

def test_starts_in_zero(self):
        entropy = OnlineEntropy(lambda x: None)
        self.assertEqual(entropy.get_entropy(), 0)

def __init__(self, attribute, target):
        self.attribute = attribute
        self.H = OnlineEntropy(target)
        self.G = defaultdict(lambda: OnlineEntropy(target))

        self.G = defaultdict(lambda: OnlineEntropy(target))