title: Google App Engine and 404 error
body: <p>I've setup a static website on GAE using hints found elsewhere, but can't figure out how to return a 404 error. My app.yaml file looks like</p>
  
  <pre><code>- url: (.*)/
    static_files: static\1/index.html
    upload: static/index.html
  
  - url: /
    static_dir: static
  </code></pre>
  
  <p>with all the static html/jpg files stored under the static directory. The above works for files that exist, but returns a null length file if they don't. The answer is probably to write a python script to return a 404 error, but how do you set things up to serve the static files that exist but run the script for files that don't?</p>
  
  <p>Here is the log from fetching a non-existent file (nosuch.html) on the development application server:</p>
  
  <pre><code>ERROR    2008-11-25 20:08:34,084 dev_appserver.py] Error encountered reading file "/usr/home/ctuffli/www/tufflinet/static/nosuch.html":
  [Errno 2] No such file or directory: '/usr/home/ctuffli/www/tufflinet/static/nosuch.html'
  INFO     2008-11-25 20:08:34,088 dev_appserver.py] "GET /nosuch.html HTTP/1.1" 404 -
  </code></pre>