Question

Exercise OPT.2 – Secret Messages (Homework 1)

I don't really get the step 3. Why should the values remain in range (0,5)? Or rather why do we have to do the modulus? Somehow I don't see how do I do it after I managed to replace all the letters with "x"'s. Thanks!

Answer 1

I think I expressed a similar question when our class hit this exercise. You can review the thread of the discussion here

http://openstudy.com/study#/updates/508f05b9e4b043900ad89834

Hope that the discussion which ensued clarifies the exercise for you

Answer 2

I agree with Screech's thread. That step is just poorly worded and can be basically ignored. Just focus on creating a function that will take a user's string input and return an ascii shifted message back. That is the purpose of the exercise. Good luck.

Answer 3

Looked closer at Opt.2 Secret Messages exercise:
first I simply shifted the ascii value over by the designated amount ('A' = 65, shift 4 over would be '69'). This works fine for all characters except the last 9 of the set (88-97) and (120-129). These outer cases are where they expect us to modify our ascii character using the modulus operator to keep the secret letter value within the range A-Z or a-z respectively. Handle each range using for loops and the 'ord' and 'chr' functions from the examples.