6.1.2.1 Traversal

The Publisher handler locates and imports the module specified in the URI. The module location is determined from the req.filename attribute. Before importing, the file extension, if any, is discarded.

If req.filename is empty, the module name defaults to "index".

Once module is imported, the remaining part of the URI up to the beginning of any query data (a.k.a. PATH_INFO) is used to find an object within the module. The Publisher handler traverses the path, one element at a time from left to right, mapping the elements to Python object within the module.

If no path_info was given in the URL, the Publisher handler will use the default value of "index".

The traversal will stop and HTTP_NOTFOUND will be returned to the client if:

Any of the traversed object's names begin with an underscore ("_"). Use underscores to protect objects that should not be accessible from the web.
A module is encountered. Published objects cannot be modules for security reasons.

If an object in the path could not be found, HTTP_NOT_FOUND is returned to the client.