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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 _unscaled_dist(self, X, X2=None):
 """ Compute the Euclidean distance between each row of X and X2, or between each pair of rows of X if X2 is None. """

        #X, = self._slice_X(X)
        if X2 is None:
            Xsq = np.sum(np.square(X),1)
            r2 = -2.*tdot(X) + (Xsq[:,None] + Xsq[None,:])
            util.diag.view(r2)[:,]= 0. # force diagnoal to be zero: sometime numerically a little negative
            r2 = np.clip(r2, 0, np.inf)
            return np.sqrt(r2)
        else:
            #X2, = self._slice_X(X2)
            X1sq = np.sum(np.square(X),1)
            X2sq = np.sum(np.square(X2),1)
            r2 = -2.*np.dot(X, X2.T) + (X1sq[:,None] + X2sq[None,:])
            r2 = np.clip(r2, 0, np.inf)
            return np.sqrt(r2)