title: How to get the id of canvas item?
body: <p>If I store the canvas item in a variable I expect that is stored as an tkinter.rectangle object which I can use later. </p>
  
  <pre><code>rec = can.create_rectangle(l, fill="blue")
  </code></pre>
  
  <p>But instead is stored as an integer &lt;&lt; class 'int' >></p>
  
  <pre><code>from tkinter import Tk, Canvas, Button
  
  def press(canv, rect):
      print("pressed")
      canv.move(rect, 10)
  
  l = [50,100,100,200]
  
  root = Tk()
  can = Canvas(root)
  can.pack()
  rec = can.create_rectangle(l, fill="blue")
  print("rec",rec)    #1
  print("type(rec) ", type(rec)) #&lt;class 'int'&gt;
  b = Button(root, text="NOTHING", command=lambda:press(can, rec))
  b.pack()
  print("type(b) = ",type(b)) #&lt;class 'tkinter.Button'&gt;
  print("b = ",b) #TCL id like .41549040
  root.mainloop()
  </code></pre>
  
  <p>When run this code it returns a error:</p>
  
  <pre><code>_tkinter.TclError: wrong # args: should be ".21823184 move tagOrId xAmount yAmount"
  </code></pre>
  
  <p>Why is it of type integer and how get the id of the canvas item to move it around later?</p>