title: Python: Message error when using bgpic() from turtle module
body: <p>I'm trying to change the background image in a turtle window. </p>
  
  <p>The code reads simply as this:</p>
  
  <pre><code>import turtle
  turtle.bgpic("france53.gif")
  </code></pre>
  
  <p>The turtle window shows up blank and I get the following error message: </p>
  
  <pre><code>Traceback (most recent call last):
  
  File "&lt;ipython-input-25-45373f8f3ea2&gt;", line 1, in &lt;module&gt;
  bgpic("france53.gif")
  
  File "&lt;string&gt;", line 1, in bgpic
  
  File "/Users/danielcharrier/anaconda/lib/python3.4/turtle.py", line 1482, in bgpic
  self._setbgpic(self._bgpic, self._bgpics[picname])
  
  File "/Users/danielcharrier/anaconda/lib/python3.4/turtle.py", line 738, in _setbgpic
  self.cv.itemconfig(item, image=image)
  
  File "&lt;string&gt;", line 1, in itemconfig
  
  File "/Users/danielcharrier/anaconda/lib/python3.4/tkinter/__init__.py", line 2416, in itemconfigure
  return self._configure(('itemconfigure', tagOrId), cnf, kw)
  
  File "/Users/danielcharrier/anaconda/lib/python3.4/tkinter/__init__.py", line 1310, in _configure
  self.tk.call(_flatten((self._w, cmd)) + self._options(cnf))
  
  TclError: image "pyimage12" doesn't exist
  </code></pre>
  
  <p>The file "france53.gif" is in the working directory. What should I do to make it work? </p>
  
  <p>I'm using the Anaconda distribution for Mac OS X.  </p>
  
  <p>Thanks!</p>