def connect_the_dots(pts):
    """given a list of tag pts, convert the point observations to
    poly-lines.  If there is only one pt, return None, otherwise connect
    the dots by copying the points and offseting by 1, producing N-1 line
    segments.

    Arguments: - `pts`: a list of point observations of the
    form [[lat1,lon1],[lat2, lon2], ... ]

    """
    if len(pts) > 1:
        # pts = [(x[1], x[0]) for x in pts]
        pts = [x[1] for x in pts]
        A = pts[:-1]
        B = pts[1:]

        coords = list(zip(A, B))
        return coords
    else:
        return None