Werkzeug

Debugging System

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Depending on the WSGI gateway/server, exceptions are handled differently but most of the time exceptions go to stderr or the error log.

Since this is not the best debugging environment Werkzeug provides a WSGI middleware that renders nice debugging tracebacks, optionally with an AJAX based debugger (which allows to execute code in the context of the traceback's frames).

Usage:

from myapplication import application
from werkzeug import DebuggedApplication, run_simple

application = DebuggedApplication(application, evalex=True)

run_simple('localhost', 4000, application)

This code spawns a Debugging Server on localhost:4000 with the debugger enabled. If you set evalex to False, the debugger is disabled.

Warning

Don't ever use the debugging middleware in a production environment since it can leak internal information that is part of the variable debug table. Even worse is a debugger with enabled evalex feature that can be used to execute code on the server!