internal timer of python class - timer

Question

I am writing some Python class which has a status attribute. I would like to be notified if the status of an object X does not change in 30 seconds i.e. I want to receive something like a "Timeout" message. I tried to use the Timer subclass of the class Threading. But I get an error
import threading
import datetime
import time
def change( ob ):
print "TIMED OUT"
ob.timer = threading.Timer( 30, change, args = ob )
ob.timer.start( )
return
class XXX(object):
def __init__( self ):
self.status = 0
self.last_change = datetime.datetime.utcnow()
self.timer = threading.Timer(30, change)
self.timer.start()
def set(self, new_status):
D = datetime.timedelta(0, 30)
if ( datetime.datetime.utcnow( ) < self.last_change + D ):
self.timer.cancel( )
self.last_change = datetime.datetime.utcnow( )
self.status = new_status
self.timer = threading.Timer(30, change, args = self )
self.timer.start( )
print "New status: ", new_status
def main():
myx = XXX()
x = 0
while ( x < 120 ):
x += 1
print "Second ", x
if ( x == 10 ):
myx.set( 20 )
elif ( x == 40 ):
myx.set( 44 )
elif ( x == 101 ):
myx.set( 2 )
time.sleep( 1 )
if __name__=='__main__':
main()
But at Second 40 in the while loop I get the following exception raised:
Exception in thread Thread-7:
Traceback (most recent call last):
File "C:\Users\alexa\Anaconda2\lib\threading.py", line 801, in
__bootstrap_inner
self.run()
File "C:\Users\alexa\Anaconda2\lib\threading.py", line 1073, in run
self.function(*self.args, **self.kwargs)
TypeError: change() argument after * must be an iterable, not XXX
The weird thing is that if I remove the arguments of the change function and then initialize the timer without passing args = self, it works. The reason why I was passing arguments for the change function is that I wanted to restart the timer if the status was updated. Any thoughts on how to do/fix this? Thanks!

Answer 1

so I figured that it's just easier to move the change function inside the XXX class. This way, one does not need to pass args = ... to the timer.