code: def sort(polylines):
      for n, c in enumerate(polylines):
          l = len(c)
          if l > 2:
              mid = c.mean(axis=0)
              distV = (c - mid)
              dists = norm(distV, axis=-1)
              firstI = np.argmax(dists)
              sign = np.sign(distV[firstI])
              dd = np.logical_or(np.sign(distV[:, 0]) != sign[0],
                                 np.sign(distV[:, 1]) != sign[1])
              dists[~dd] = 0
              lastI = np.argmax(dists)
              ind = _sort(c, firstI, lastI)
              c = c[ind]
              polylines[n] = c