code: def showDraw(self, fignum=1):
          
          if self._patches == []:
              print("Please setDraw() before showDraw(), then try again.")
              return
          else:
              fig = plt.figure(fignum)
              fig.clear()
              ax = fig.add_subplot(111, aspect='equal')
              [ax.add_patch(i) for i in self._patches]
              bbox = self._patches[0].get_path().get_extents()
              x0 = 2.0 * min(bbox.xmin, bbox.ymin)
              x1 = 2.0 * max(bbox.xmax, bbox.ymax)
              ax.set_xlim(x0, x1)
              ax.set_ylim(x0, x1)
              # x1,y1=tuple(self.nextp0)
              # x2,y2=tuple(self.nextp1)
              # x3,y3=tuple(self.nextpc)
              # ax.plot([x1,x2,x3], [y1,y2,y3], 'o')#, ms=5, fc='b', ec='b')
              x, y = tuple(self.next_p0)
              ax.plot(x, y, 'o', ms=10, c='b')
  
              ax.annotate(s=self._anote['name'],
                          xy=self._anote['xypos'],
                          xytext=self._anote['textpos'],
                          textcoords='data',
                          arrowprops=dict(arrowstyle='->'),
                          rotation=-90,
                          fontsize='small')
  
              fig.canvas.draw()
              plt.grid()
              plt.show()
docs: show the element drawing
  
          :param fignum: define figure number to show element drawing