How to use the pygeos.boundary function in pygeos

polygon : shapely.geometry.Polygon
      Polygon to query
    points : (n, 2) float
      2D points

    Returns
    ------------
    distance : (n,) float
      Minimum distance from each point to polygon boundary
    """

    try:
        import pygeos
        # the pygeos way is 5-10x faster
        pg_points = pygeos.points(*points.T)
        pg_boundary = pygeos.boundary(pygeos.Geometry(polygon.wkt))
        distance = pygeos.distance(pg_boundary, pg_points)
    except BaseException:
        # in pure shapely we have to loop
        inverse = polygon.boundary
        distance = np.array([
            inverse.distance(i) for i in MultiPoint(points)])

    return distance