title: How can I delet an axvspan line?
body: <p>I have a plot with a time series and one or several axvspan lines to highlight some areas and to extract the time series value and instant but I would like to have the possibility to delete one or all those axvspan lines with a button. I have looked some examples on how to delete lines (<a href="https://stackoverflow.com/questions/17819260/how-can-i-delete-plot-lines-that-are-created-with-mouse-over-event-in-matplolib/17820452#comment26010581_17820452">How can I delete plot lines that are created with Mouse Over Event in Matplolib?</a>) but I can´t find nothing related with axvspan lines.
  This is the code that I'm using to create the axvspan line(s)</p>
  
  <pre><code>    def on_click(event):
          global x0
          x0 = event.xdata
  
      def on_release(event):
          global force_values
          if force_value == "Min":
              self.axes.axvspan(x0,event.xdata, facecolor='y', alpha=0.5)
              get_data(frames,force_values,x0,event.xdata)
          else:
              self.axes.axvspan(x0,event.xdata, facecolor='r', alpha=0.5)
              get_data(frames,force_values,x0,event.xdata)
  </code></pre>
  
  <p>Thanks in advance for your help. 
  Kind Regards 
  Ivo</p>