yesno()

The following script shows how the user can be prompted for an answer.

#!/usr/bin/env python
import string
import sys

#
#
#
def yesno( prompt):
    sys.stdout.write( prompt)
    sys.stdout.flush()
    answer = sys.stdin.readline().upper().strip()
    if answer == 'Y' or answer == 'YES':
        return 1
    else:
        return 0

if not yesno( "Do really want it"):
    #
    # nothing is executed
    #
    return

execute_critical_code()