Remove trailing slash on App Engine

class BaseRequestHandler(webapp.RequestHandler):
    def initialize(self, request, response):
        webapp.RequestHandler.initialize(self, request, response)
        if request.path.endswith("/") and not request.path == "/":
            redirect = request.path[:-1]
            if request.query_string:
                redirect += "?" + request.query_string
            return self.redirect(redirect, permanent=True)

Or if you are using Tornado it's just:

@tornado.web.removeslash