I've got a tiny bit of code to display a file

in app.yaml

- url: /(.*\.(gif|png|jpg))
  static_files: static/\1
  upload: static/(.*\.(gif|png|jpg))

in main.py

...
class ShowImage(webapp.RequestHandler):
  def get(self):
      rootpath = os.path.dirname(__file__)
      file = rootpath + "/static/tracker.gif";
      fh=open(file, 'r')
      self.response.out.write(fh.read())
      fh.close 
...

I can see the files gone up by going to my *.appspot.com/tracker.gif (as per the app.yaml) But using *.appspot.com/showimage returns

Traceback (most recent call last):
  File "/base/python_lib/versions/1/google/appengine/ext/webapp/__init__.py", line 510, in __call__
    handler.get(*groups)
  File "/base/data/home/apps/APPNAME/2.341131266814384624/main.py", line 170, in get
    fh=open(file, 'r')
IOError: [Errno 2] No such file or directory: '/base/data/home/apps/APPNAME/2.341131266814384624/static/tracker.gif'