''' Purpose: produce and print the reverse of a user-supplied word
    (using accummulation)
'''

# Please ask questions if this doesn't make sense and feel free to tell me to scroll through the code if
# you missed something or ask a TA - I know there's a lot of notes!
# PLEASE ASK QUESTIONS IF ACCUMULATORS DONT MAKE SENSE QUITE YET
### get word
reply = input( "Enter word: " )

word  = reply.strip()

# Just as a reminder, .strip() takes off all leading and trailing whitespace from a string :)

### get a copy of the word through accumulation

# Accumulation is an important concept in 1112! We want to build up an answer.
# We want to initialize an accumulator (remember this word!)

reverse = "" # ACCUMULATOR MUST START OFF AS EMPTY STRING FOR STRING ACCUMULATIONS

# Initialize reverse to an empty string!
# Why do we initialize it as an empty string? Because we want to add to it to build up an answer!
# We want to add more characters to this empty string until we get our final string answer!

# WRITE THIS DOWN: ACCUMULATOR IS INITIALIZED OUTSIDE THE FOR LOOP BEFORE THE FOR LOOP!!

# As we go through the loop, we keep adding a new character in our original string to reverse.
for ch in word :
   # reverse = "" # If we have the accumulator initialized here, we messed it all up because it'll be set as
                    # an empty string each time so it never "builds up" - it resets itself
                    # By setting it outside the for loop, we can use it before and after the loop while
                    # the loop just modifies the accumulator (reverse in this case)
    print( "ch =" , ch )
    # reverse = reverse + ch #(wrong!)
    reverse = ch + reverse # What we're doing now is we're taking each character in the original sequence
                            # and adding it to the front so apple becomes elppa because it'll add the a then the p
                            # in front of that a then the p after that and so on so that reverses the string :)
    print( reverse )

# Recall that reverse = something + reverse will add that new thing we wanna add and the last stored
# value of reverse.
### print reverse
print( reverse ) # PRINTS FINAL REVERSE STRING

# Again, the purpose of accumulators is to build up something.
# For building up a string, we initialize it using an empty string "" and then keep adding to it
# by saying accumulator = accumulator + (whateverIwannaadd) through string concatenation
# That way it keeps getting the previous value of accumulator and adding the new string(s) we wanna add to it
# as we go through the for loop.