--- title: Eboard 10 Reading lists and tables from files number: 10 section: eboards held: 2017-09-15 --- CSC 151.01, Class 10: Reading lists and tables from files ========================================================== _Overview_ * Preliminaries * Notes and news * Upcoming work * Extra credit * Questions * Quiz * Debrief * Lab * Debrief ### News / Etc. * If you are a second-year student, please get one of the short survey forms from the mentors. * Please make sure to return your computer cards to the jar. * Answer key for homework 3 distributed last night. * Code of conduct to be distributed electronically. We'll discuss on Monday. * I do not yet have my grading system up and running. When I do, I will distribute grades. Until then, I cannot. * If you ask me a face-to-face question outside of office hours, you may find that I am abrupt. I apologize. But I am often heading off to a meeting or class or preparing for one of those meetings or classes. * Email generally works well. Put HELP or QUESTION in the title. * If I haven't responded within 24 hours, email again. * I've added office hours on Monday for folks with exam questions. * Email over the weekend is also great. * Remember to book office hours at . ### Upcoming Work * [Writeup for class 9](../writeups/writeup09) due TONIGHT at 10:30 p.m. * Exercise 4 * To: * Subject: CSC 151.01 Writeup 9 (YOUR NAMES) * [Writeup for class 10](../writeups/writeup10) due Monday at 10:30 p.m. * Exercise 6 * To: * Subject: CSC 151.01 Writeup 10 (YOUR NAMES) * Read: [Boolean values and predicate procedures](../readings/boolean) for Monday's class. * Read: [Filtering lists](../readings/list-filters) for Monday's class. * Exam 1 * Prologue due TONIGHT * Exam due Tuesday night * Cover sheet due Wednesday in class * Epilogue due Wednesday night ### Extra credit (Academic/Artistic) * CS Table, Tuesday: (H)Activism ### Extra credit (Peer) * Men's Soccer vs. Buena Vista, Sept. 17 at 2:00 p.m. * Elephantitis, this weekend, Grinnell High School and Grinnell Middle School. (Ultimate (flying disc) tournament) ### Extra Credit (Misc) _None at the moment._ ### Other Good Things ### Friday PSA * Don't feel pressure. The choices you make can/should be your own. * Consent is absolutely, positively, necessary. * Embrace self-gov! ### Exam Questions How should I make the cover sheet? : Hand write. It's easy. ### Other Questions Why three semicolons? : Makes it easier to distinguish 6P's from other kinds of comments. : Makes it easier to extract/process. Quiz ---- Debrief from prior class ------------------------ Thinking * Look back to examples from the reading and try to understand what they were doing. * Don't let the big list distract you. For many things, you'll focus on one value (or two) and then use `map` or `sort` or `reduce` to work with the larger list. * Trust `map`, `reduce`, and `sort`. Formatting ``` (define zf->cf (lambda (entry) (append (take (drop entry 3) 3) (take entry 2) (drop entry 5)))) ``` vs. ``` (define zf->cf (lambda (entry) (append (take (drop entry 3) 2) (take entry 3) (drop entry 5)))) ``` Documentation * Please use three semicolons for the six P's, not one. * Please put a space after the three semicolons. Lab --- Do the lab on [reading data from files](../data-from-files) Are we better off doing computations by hand or by computer? : What do you think? I remember writing `sort-by-city`, but I can't find it. : You should be able to write it much more quickly this time. Did you really mean 51111? : No. Use 50112. What is the writeup? : Exercise 6 Does Grinnell really have two zip codes? : I was surprised to see that, but it appears that it does. : Or maybe our data are bad. Debrief ------- ### Past labs * Yes, it's helpful to keep the results of your past labs. You should probably make it a practice to email those to your partners. * If you use the results of a past lab in a new lab, you should insert a short citation. "`sort-by-city` taken from lab 9, completed by Stu Dent and An Other" ### Other observations While Wednesday's lab was a struggle for some of you, this one seemed better (at least from an observer's perspective). You are mastering complex material. Naming is important. ``` (define sort-by-city (lambda (c1 c2) (string-ci compare-by-city)) ``` Sometimes it's less important to be perfect than to get the job done. (And sometimes just getting the job done is pretty close to perfect.) ``` (define city-first (lambda (city) (cons (list-ref city 3) city))) (define search-by-city (lambda (cities city) (cdr (assoc city (map city-first cities))))) ```