Calculate the angle between two vectors x and y.

def angle_between_vectors(x, y):
    """Calculate the angle between two vectors x and y."""
    first_step = abs(x[0] * y[0] + x[1] * y[1] + x[2] * y[2]) / (
        np.sqrt(x[0]**2 + x[1]**2 + x[2]**2) *
        np.sqrt(y[0]**2 + y[1]**2 + y[2]**2))
    second_step = np.arccos(first_step)
    return (second_step)