python - Flask Debugger not working under Windows -

i newbie python attempting experiment sample code under windows 8.1.

on http://flask.pocoo.org/docs/0.10/quickstart/ says "if enable debug support server reload on code changes, , provide helpful debugger".

i have added code app.run(debug=true) sample code on above page. server reload on code changes (as promised) when create syntax error "helpful debugger" not show. instead error message in command prompt.

any ideas why? suspect answer might here can't enable debug mode in flask largely uninteligible me.

so far have tried restarting machine , putting code in different locations. not in forked environment (as best know). curious source code shown below:

from flask import flask app = flask(__name__)  werkzeug.debug import debuggedapplication app.wsgi_app = debuggedapplication(app.wsgi_app, true)  @app.route('/') def hello_world():     return 'hello world! #note deliberate syntax error   if __name__ == '__main__':     app.debug = true     app.run() 

the debugger debugging exceptions in syntactically valid program. try raising exception in code, visit url in browser window, , see helpful debugger. see http://flask.pocoo.org/snippets/21/

syntax errors shown on console have seen. that's how works.