class MainHandler(web.RequestHandler): def initialize(self): self.form = TestForm(meta={'locale': self.locale}) def get(self): return self.render('page.html', form=self.form) def post(self): # just mock the form processing # as it will always raise error self.form.process(data={'username': '******'}) self.form.validate() return self.render('page.html', form=self.form)