Modern Python Standard Library Cookbook

How to do it...

The cgitb module provides tools to format an exception and its traceback as HTML, so we can leverage it to implement a WSGI middleware that can wrap any web application to provide better error reporting in the browser:

import cgitb import sys class ErrorMiddleware: """Wrap a WSGI application to display errors in the browser""" def __init__(self, app): self.app = app def __call__(self, environ, start_response): app_iter = None try: app_iter = self.app(environ, start_response) for item in app_iter: yield item except: try: start_response('500 INTERNAL SERVER ERROR', [ ('Content-Type', 'text/html; charset=utf-8'), ('X-XSS-Protection', '0'), ]) except Exception: # There has been output but an error occurred later on. # In that ...