Suppose I have a function
def app2(environ, start_response)
If I know that a server implements WSGI, how can I tell the server to call app2 when it receives a HTTP request? app2 here is a function that takes a dictionary and returns a response (a WSGI application).
If, as it sounds from your comment, your question is about Google App Engine, it provides a convenience function
run_wsgi_appfor running WSGI apps. So if your function is calledapp2, you would runFor more, see http://code.google.com/appengine/docs/python/tools/webapp/utilmodule.html#run_wsgi_app