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python exception like structure with a timer

I have a program that depends on being able to query a online database. If the internet connection fails, I want the program to continue, but with different parameters. I am currently using an exception like the following:

Code:

try: 

        (query_status, query_info) = CDDB.query(disc_id) 

        results = cd_info(query_status, query_info, disc_id)

        

except:

        do something here

this above method works, but unsatisfactory. The problem is I need to wait for over a minute, maybe two for it ito time out.

Is there a method I could use, to place my two lines of code, like an exception. The result would be if the commands did not finish executing in a set amount of time(say 20 seconds). a secondary clause would execute.

for example:

Code:

try:

        (query_status, query_info) = CDDB.query(disc_id) 

        results = cd_info(query_status, query_info, disc_id)

if not finished in 20 seconds:

        execute this clause

How about :-

import time
x = time.time()
#your code here
y = time.time()
if y > (x+20):
do a
else:
do b

I have not tested this but I think it should work. Let me know.

Quote:

Originally posted by davholla
How about :-

import time
x = time.time()
#your code here
y = time.time()
if y > (x+20):
do a
else:
do b

I have not tested this but I think it should work. Let me know.

Yeah even better is:

Code:

import time

time.sleep(60)

Which sleeps 60 seconds.

Quote:

Originally posted by davholla
How about :-

import time
x = time.time()
#your code here
y = time.time()
if y > (x+20):
do a
else:
do b

That will not do the trick: The call to CDDB.query() will take 1 or 2 minutes. Your code only measures the time it took afterwards.

I think the question was how to make the call to CDDB.query() take less time in case the connection fails.

@shanenin
I don't know about the CDDB-module, but did you look for some way in that module to specify the time-out? That would be the prefferred solution of course. If there's no such way, this might help:

Code:

#!/usr/bin/env python



import time

import signal



# Signal hander function.

# Makes an Exception occur.

def alarmHandler(signalNumber, stackFrame):

        raise IOError, "Time-out"



# Setting handler function.

# The handler will be run when a SIGALARM

# interrupts the program

signal.signal(signal.SIGALRM, alarmHandler)



# Setting the shorter time-out here: 5 secs.

# This will interrupt the program after 5 secs

# from now.

# Comment out the line below to simulate normal

# time-out or successful query.

signal.alarm(5)



try:

        # Simulate a query timing out in 1 minute.

        print "Start (simulated) query time-out"

        time.sleep(60)  # Put your query-call here instead.

except IOError:

        print "Time out! " * 5



print "Finished"

That last code worked, thanks. :-)