No handlers could be found for logger "apscheduler.scheduler"

from apscheduler.scheduler import Scheduler
import os
class ListHref():
    def __init__(self):
       print 'In ListHref Class!'
       self.name_hrefs = {}
       self.name_img = {}
       self.path = os.path.dirname(__file__)
       print 'Out ListHref Class'
    def other_function():...

def job(): #function named job
    print 'In job!'
    book_href = ListHref()
    print 'book_href created!'

if __name__ == "__main__":
    sched = Scheduler()
    #job() #it's ok if job() called only
    sched.daemonic = False #non daemon thread 
    sched.add_interval_job(job,minutes=0.1)
    sched.start()

Problem: If call job() only instead of sched,it's ok So I am confused that why the init(self) cannot called completely? and what's wrong with 'No handerls could be found for logger "apscheduler.scheduler"'? Above python code result:

In job()

In ListHref Class!

No handerls could be found for logger "apscheduler.scheduler"

In job()

In ListHref Class!

In job()

In ListHref Class!

...(so on)