if the files were uploaded with a form wrapper (i.e. a multipart/form-data Content-Type); if this format was not used the raw uploaded data is available in self.request.body. By default uploaded files are the current exception in sys.exc_info, so write_error must use e.g. traceback.format_exception instead of traceback.format_exc). It is also possible to generate an error page from regular handler methods =False or debug=True. Template syntax A Tornado template is just HTML (or any other text-based format) with Python control sequences and expressions embedded within the markup: