python - Using Flask's "after_request" handler to get tracebacks of errors -

the documentation after_request says "as of flask 0.7 function might not executed @ end of request in case unhandled exception occurred." there way change after_request functions called unhandled exceptions, example log traceback?

use teardown_request instead.

register function run @ end of each request, regardless of whether there exception or not.

these functions not allowed modify request, , return values ignored. if exception occurred while processing request, gets passed each teardown_request function.

from flask import flask  app = flask(__name__) # unhandled teardown won't happen while in debug mode # app.debug = true # set if need full traceback, not exception # app.config['propagate_exceptions'] = true  @app.route('/') def index():     print(test)  @app.teardown_request def log_unhandled(e):     if e not none:         print(repr(e))         # app.logger.exception(e)  # works propagate_exceptions  app.run('localhost') 

note time teardown_request called, traceback has fallen out of scope; exception available. can change setting propagate_exceptions = true, although may have performance issues. given traceback logged flask already, may easier configure logging rather trying log yourself.