signal_test.py

import signal, os, time

def handler(signum, frame):
    print 'Signal handler called with signal', signum
    raise IOError("Couldn't open device!")

# Set the signal handler and a 5-second alarm
signal.signal(signal.SIGALRM, handler)
signal.alarm(5)

time.sleep(6) # long task like handling file system or device

signal.alarm(0)          # Disable the alarm

########################################################################
# run result of python signal_test.py
# Signal handler called with signal 14
# Traceback (most recent call last):
#   File "signal_test.py", line 11, in <module>
#     time.sleep(6)
#   File "signal_test.py", line 5, in handler
#     raise IOError("Couldn't open device!")
#IOError: Couldn't open device!