title: How to hide and show canvas items on tkinter?
body: <p>I know that <code>pack</code> and <code>pack_forget</code> can be used to show or hide widgets. Which are the equivalent commands for items on a canvas?</p>
  
  <p>Notice: It would be better to keep the complete item information, including its position. This is not the case with <code>pack</code>/<code>pack_forget</code>, where you need to inform the position again whenever you use pack.</p>