Implement the command line alarm script instance with Python

Preface:

This article introduces how to use python to create a simple alarm. It can be run on the command line terminal. It takes a minute as a command line parameter, after which it will print the "wake-up" message and ring the alarm.

Here's the script:

# alarm_clock.py
 
# Description: A simple Python program to make the computer act 
# like an alarm clock. Start it running from the command line 
# with a command line argument specifying the duration in minutes 
# after which to sound the alarm. It will sleep for that long, 
# and then beep a few times. Use a duration of 0 to test the 
# alarm immediiately, e.g. for checking that the volume is okay.
 
# Author: Vasudev Ram - http://www.dancingbison.com
 
import sys
import string
from time import sleep
 
sa = sys.argv
lsa = len(sys.argv)
if lsa != 2:
  print "Usage: [ python ] alarm_clock.py duration_in_minutes"
  print "Example: [ python ] alarm_clock.py 10"
  print "Use a value of 0 minutes for testing the alarm immediately."
  print "Beeps a few times after the duration is over."
  print "Press Ctrl-C to terminate the alarm clock early."
  sys.exit(1)
 
try:
  minutes = int(sa[1])
except ValueError:
  print "Invalid numeric value (%s) for minutes" % sa[1]
  print "Should be an integer >= 0"
  sys.exit(1)
 
if minutes < 0:
  print "Invalid value for minutes, should be >= 0"
  sys.exit(1)
 
seconds = minutes * 60
 
if minutes == 1:
  unit_word = " minute"
else:
  unit_word = " minutes"
 
try:
  if minutes > 0:
    print "Sleeping for " + str(minutes) + unit_word
    sleep(seconds)
  print "Wake up"
  for i in range(5):
    print chr(7),
    sleep(1)
except KeyboardInterrupt:
  print "Interrupted by user"
  sys.exit(1)
 
# EOF

Conclusion: