@staticmethod
    def _get_alpha(b):
        assert b <= 16 <= 4, 'b=%d should be in range [4,16]' % b
        alpha = (0.673, 0.697, 0.709)
        if b <= 6:
            return alpha[b-4]
        return 0.7213 / (1.0 + 1.079 / (1 << b))
dataset/ETHPy150Open douban/dpark/dpark/hyperloglog.py/HyperLogLog._get_alpha/swapped operands of `<=`