looking_for_yes_no = True

while ( looking_for_yes_no == True ):

    reply = input('yes or no? ')

    reply = reply.strip()
    reply = reply.lower()

    if reply == 'yes':
        print( reply )
        looking_for_yes_no = False

    elif reply == 'no':
        print( reply )
        looking_for_yes_no = False

    else:
        print( 'Invalid response' )

print( 'Thank you for indicating your choice.' )

to_do = ['feed dogs', 'give dogs water', 'sweep up dog fur', 'watch lost in space']

print()

while len(to_do) != 0:
    task = to_do.pop()
    print( task, 'done' )
    print( 'still to be done:', to_do)
    print()