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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _kendall_tau_diff(self, a: np.ndarray, b: np.ndarray, i) -> Tuple[int, int]: """Compute difference in concordance of pairs in split sequences. Consider splitting a and b at index i. Parameters a ? b ? Returns ------- diff_pos Difference between concordant pairs for both subsequences. diff_neg Difference between non-concordant pairs for both subsequences. """

        # compute ordering relation of the single points a[i] and b[i]
        # with all previous points of the sequences a and b, respectively
        a_pos = np.zeros(a[:i].size, dtype=int)
        a_pos[a[:i] > a[i]] = 1
        a_pos[a[:i] < a[i]] = -1
        b_pos = np.zeros(b[:i].size, dtype=int)
        b_pos[b[:i] > b[i]] = 1
        b_pos[b[:i] < b[i]] = -1
        diff_pos = np.dot(a_pos, b_pos).astype(float)

        # compute ordering relation of the single points a[i] and b[i]
        # with all later points of the sequences
        a_neg = np.zeros(a[i:].size, dtype=int)
        a_neg[a[i:] > a[i]] = 1
        a_neg[a[i:] < a[i]] = -1
        b_neg = np.zeros(b[i:].size, dtype=int)
        b_neg[b[i:] > b[i]] = 1
        b_neg[b[i:] < b[i]] = -1
        diff_neg = np.dot(a_neg, b_neg)

        return diff_pos, diff_neg