''' Purpose: demonstrate the printing of a string of characters
'''

# get a string 
reply = input( 'Enter a string: ' )

### print the characters one at a time
# you don't know how many characters there are in the string reply --> need loop
# reply is a SEQUENCE of characters (string) so we can go through the string in a for loop
#   in love_is_all_you_need, the SEQUENCE is a range of numbers
#   here the SEQUENCE is a string
# after the keyword in, you can specify the sequence of your choice
#   range of numbers = sequence of numbers
#   string = sequence of characters
# the type of sequence will determine what the loop variable represents
#   if range, then loop variable will take on numbers within the range of numbers
#   if string, then loop variable will take on each character within string
# here, we name our loop variable ch (stands for character)

for ch in reply:
    # 1st time: ch = first character in reply = reply[0]
    # 2nd time: ch = second character in reply = reply[1]
    # and so on until you run out of characters in reply

    print( ch )

print()

hmmm = ''    # hmmm is initialized as an empty string
for ch in reply:
    print( 'hmmm before update:', hmmm )

    hmmm = ch + hmmm    # string concatenation
    # here we are building the reverse of the original string
    # we are sticking each character at the BEGINNING of the accumulator
    # the order in which you concatenate strings matter!

    print( 'hmmm after update:', hmmm )

    # if reply = 'apple'
    # ch = 'a', hmmm = ''
    # --> ch + hmmm = 'a' + '' => hmmm = 'a'

    # ch = 'p', hmmm = 'a'
    # ch + hmmm = 'p' + 'a' => hmmm = 'pa'

    # ch = 'p', hmmm = 'pa'
    # ch + hmmm = 'p' + 'pa' => hmmm = 'ppa'

    # ... until you reach the end of reply
# now you have hmmm as the reverse of reply