Glossary

component
A part of a URL delimited by slashes. The URL “/help/about” contains two components: “help” and “about”.
generation
The act of creating a URL based on a route name and/or variable values. This is the opposite of matching. Finding a route by name is called named generation. Finding a route without specifying a name is called nameless generation.
mapper
A container for routes. There is normally one mapper per application, although nested subapplications might have their own mappers. A mapper knows how to match routes and generate them.
matching
The act of matching a given URL against a list of routes, and returning the routing variables. See the route entry for an example.
minimization
A deprecated feature which allowed short URLs to match long paths. Details are in the Backward Compatibility section in the manual.
route

A rule mapping a URL pattern to a dict of routing variables. For instance, if the pattern is “/{controller}/{action}” and the requested URL is “/help/about”, the resulting dict would be:

{"controller": "help", "action": "about"}

Routes does not know what these variables mean; it simply returns them to the application. Pylons would look for a controllers/help.py module containing a HelpController class, and call its about method. Other frameworks may do something different.

A route may have a name, used to identify the route.

route path
The URL pattern in a route.
routing variables

A dict of key-value pairs returned by matching. Variables defined in the route path are called path variables; their values will be taken from the URL. Variables defined outside the route path are called default variables; their values are not affected by the URL.

The WSGI.org environment key for routing variables is “wsgiorg.routing_args”. This manual does not use that term because it can be confused with function arguments.