title: PPM file data cannot be recognized
body: <p>I'm writing a simple picture editor. It uses PPM files. From what I can tell, I feel like my code should work. However, I get this error</p>
  
  <pre><code>Traceback (most recent call last):
    File "/home/zach/Downloads/piceditor (1).py", line 84, in &lt;module&gt;
      main()
    File "/home/zach/Downloads/piceditor (1).py", line 69, in main
      image = Image(Point(100,100), filename)
    File "/home/zach/Downloads/graphics.py", line 770, in __init__
      self.img = tk.PhotoImage(file=pixmap[0], master=_root)
    File "/usr/lib/python3.1/tkinter/__init__.py", line 3272, in __init__
      Image.__init__(self, 'photo', name, cnf, master, **kw)
    File "/usr/lib/python3.1/tkinter/__init__.py", line 3228, in __init__
      self.tk.call(('image', 'create', imgtype, name,) + options)
  _tkinter.TclError: couldn't recognize data in image file "pig.ppm"
  </code></pre>
  
  <p>My code looks like this</p>
  
  <pre><code>def main():
  print("Image Editor")
  print()
  filename = input("name of image file: ")
  print()
  
  with open(filename) as f:
      formatind = f.readline()
      width, height = [int(x) for x in f.readline().split()]
      colordepth = f.readline()
      array = []
      for line in f:
          array.append([int(x) for x in line.split()])
  
  win = GraphWin("Image Editor!", width, height)
  
  image = Image(Point(100,100), filename)
  
  Display(image, array, width, height, win)
  
  inf.close()
  win.getMouse()
  win.close()
  
  main() 
  </code></pre>
  
  <p>And my Display function looks like this</p>
  
  <pre><code>def Display(image, array, width, height, win):
  
  for i in range(width):
      for j in range(0, height, 3):
          colors = color_rgb(array[i][j], array[i][j+1], array[i][j+2])
          image.setPixel(i, j, colors)
          image.draw(win)
  
  return
  </code></pre>
  
  <p>This is the ppm file i'm using</p>
  
  <pre><code>P3
  6 8
  255
  249 249 249 255 255 255 250 250 250 255 255 255 250 250 250 250 250 250 254 255 255 251 255 255 
  249 251 255 253 249 255 255 248 255 255 234 255 255 242 255 255 245 253 255 246 243 255 253 241 
  255 255 237 255 255 237 252 255 241 249 255 246 249 255 253 254 255 255 255 252 255 255 248 241 
  255 251 239 254 247 241 252 254 253 252 255 255 251 255 255 242 242 242 255 255 255 241 241 241 
  0 0 0 0 0 0 4 4 4 20 20 20 236 236 236 252 252 252 254 255 253 248 255 250 
  0 0 0 0 0 0 4 4 4 20 20 20 236 236 236 252 252 252 254 255 253 248 255 250 
  </code></pre>
  
  <p>I cannot for the life of me figure out why it won't recognize the data in the file.</p>
  
  <p>Any help would be great. Thanks</p>