wsgi_extract.py

# standard wsgi middleware
def some_wsgi_middleware(app):
    def middleware(environ, start_response)
        # here's the trick - set status/headers in the function scope
        status = headers = None
    
        def custom_start_response(status, headers, exc_info):
            # they get overwritten here from func args
            pass
    
        response = app(environ, custom_start_response)
        
        if status == '404':
            start_response('200', [])
            return 'something something
        else:
            start_response(status, headers)
            return response
    return middleware