Question

Python: 2.7.3

Flask: 0.9

Hi, I want to make car simulator using Apscheduler. Each car has distance column in the database that will be incremented regularly.

Here’s the import part

from __future__ import with_statement
from flask import Flask, request, session, g, redirect, url_for, \
    abort, render_template, flash, views
from sqlite3 import dbapi2 as sqlite3
from contextlib import closing
from apscheduler.scheduler import Scheduler

and here’s the snippet of the code:

sched = Scheduler()
sched.add_interval_job(moveAllCars, seconds = 5)
sched.start()

def moveAllCars():
    print "debug 1"
    dbCommand = g.db.execute('SELECT CarID FROM Car')
    print "debug 2"
    #and so on

I did not write the full code because the error happened right after ‘debug 1’ with the error message: no handlers could be found for logger “apscheduler.scheduler”. Google does not help much.

But the scheduler is still running, printing only ‘debug1’ every 5 seconds. The error message only come out during the first loop.

Anyone know the solution? Thanks before

[UPDATE]

After using logging, I found out it is RunTimeError: working outside of request context. Is there any other solution other than using with app.test_request_context?

Answer 1

g is probably a threading.local(). Different threads see different values in it.

g.db is probably assigned a new db connection per request. No current request – no connection.

You could create db connection in move_all_cars() or pass it explicitly as a parameter.