A simple clock in Py3

clock.py

#!/usr/bin/python3

import sys
import time
import datetime

BS_CHAR = '\u0008'
DATE_FMT = '%Y-%m-%d %H:%M:%S'

def clock():
    while True:
        now = datetime.datetime.now()
        sys.stdout.write(BS_CHAR * 40)
        sys.stdout.write(now.strftime(DATE_FMT))
        sys.stdout.flush()
        time.sleep(1) # sleep for 1 second

def main():
    try:
        clock()
    except KeyboardInterrupt:
        pass

if __name__ == '__main__':
    main()