How to Interrupt Sleep Function in Python

[Xena]

Hello programming gurus,

I'm looking for a function in the standard library or pywin32 package that will block until a certain condition is met or it is interrupted by Ctrl-C. and for that i have decided to write sleep function to satisfy the condition,so can anyone suggest me how to write the sleep function using python.

Regards,

[Timothi]

To write a sleep function in python we more generally use the following convention

findertools.sleep()

Tell the finder to put the Macintosh to sleep, if your machine supports it.

You can hook the it on the main thread and just pass it. And let the threads execute.

[PARRISH]

Well you've certainly picked a ticklish area to run into problems. First, forget about the threading aspects for the moment. AFAICT the smallest program which reproduces your problem is:

import signal
import time

def handler (*args):
pass
      signal.signal(signal.SIGBREAK, handler)
       time.sleep (10)

Now run that and do a ctrl-break somewhere in that time.sleep. Sure enough...

Traceback (most recent call last):
File "C:\data\temp\sig3.py", line 8, in <module>
time.sleep (10)
IOError: [Errno 4] Interrupted function call

Under the covers, the sleep function is implemented as a WaitForSingleObject call with a timeout. The object being waited on is an anonymous event which is set from a console ctrl handler when one of those interrupts happens (ctrl-c / ctrl-break / shutdown). This makes sure that the (otherwise blocking) sleep can be interrupted.

[RichiRich]

This function suspends execution for the given number of seconds. The argument may be a floating point number to indicate a more precise sleep time.

The actual suspension time may be less than that requested because any caught signal will terminate the sleep() following execution of that signal's catching routine.

time.sleep(t)

Here is the detail of parameters:

• t: This is the number of seconds execution to be suspended.

This produces following result:
Start : Tue Mar 17 10:19:18 2009
End : Tue Mar 17 10:19:23 2009