I cannot tell you how grateful I am that you took the time to do all of this. I have been working on it all day and you are a better teacher in a few minutes than my teacher has been in 4 months. THANK YOU!
And thank you again, Mitya. I really appreciate your time and effort too! Someday I'll be advanced enough to understand it lol I'm going to take a break and work on it more tomorrow. I'll be back. Thank you! On Wednesday, December 26, 2012 6:57:39 PM UTC-5, Joshua Landau wrote: > THIS IS A LONG POST, BUT IF YOU WANT TO LEARN YOU SHOULD READ IT. SERIOUSLY. > > > UNLIKE Mitya Sirenef's THIS DOES NOT ASSUME MORE KNOWLEDGE THAN IS IN YOUR > POST ALREADY, ALTHOUGH HIS IS DEFINITELY BETTER OVERALL. AS SUCH, THERE ARE > NO FUNCTIONS. > > > > OK. There are several small errors in here, but there's nothing too large or > worth much worry. > > > > On 26 December 2012 21:40, <bobflipp...@gmail.com> wrote: > > > I really hope you can help! > > I need to create a program where the user can order any combination and > quantity of 3 products. I then offer a 10% discount if the customer correctly > answers a trivia question. After that, there are 3 choices for shipping. > > > > I have most of the program completed but I'm struggling with the most > important parts :/ I get the total of multiple orders of the same item, but > we can't figure out how to total the entire order - before discounts and > shipping - and then where to put any code referring back to the trivia > question. Can somebody please help me with this? I would really appreciate it! > > > > > > You write that you "need" to do this, which may hint that this is some sort > of homework. If so, it's generally a nice thing to say as much. That said, as > long as you've given a good shot at it it's normally fine. > > > This is the code: > > > > > > My *very first* thought about this code is that it's really badly spaced. > Don't put lines together so much! [https://gist.github.com/4383950] shows how > much nicer things look when they're partitioned more. You may not agree, but > it took about 10 seconds and I prefer it. > > > shop_again = 'y' > > > > > > Hold on! Hold on! > shop_again should have a True/False value. It is screaming to be a boolean. > "y" is a letter, not a boolean. Thus: > > > shop_again = True > > > > > This is important because you don't really want to get confused with all your > types. What if shop_again was later changed to be True when a button was > clicked. Why on earth would you set it to "y"? You'd set it to True. Thus, > the sensible option is to have your types right from the very start. > > > > print("Welcome to the Star Wars Shop!") > > > customer = eval(input("Is there a customer in line? (1 = yes, 2 = no)> ")) > > > > eval(input(TEXT)) is a *bad* idea. > > > First of all, eval is really dangerous. Answer "yes" instead and it'll just > crash. Answer True and it'll run... BUT do *neither* the if or the elif! > That's *bad*. > > > Secondly, you don't need it. Your: > > > "if(customer == 1)" could be "if(customer == '1')", which would work without > the eval. > > > And then you've got the standard of "Y/N". So a better question would be: > > > > > customer = input("Is there a customer in line? [Y/N]> ") > > > Finally, you want to accept "Y" *and* "y", so you'd really want: > > > > > customer = input("Is there a customer in line? [Y/N]> ").lower() > > > > --------- > customer = input("Is there a customer in line? [Y/N]> ").lower() > > > > Because customer really deserves to be boolean [True/False], you'd want to > change it immediately. > > > customer = (customer == "y") > > > This second line assumes that all non-"y"s are False, but that's a folly > you'll have to live with for now. > > > > while shop_again == 'y': > > > > > > If you've changed shop_again to be boolean: > > > while shop_again: > > Some people don't get how this line would make sense. But it does. The > "while" statement only cares if it's value it gets is "truthy". Here are lots > of truthy things: > > > > > "y" == "y" > True > False == False > not False > "egg loaf" > [1, 2, 1, False, False] > > > and here are some falsy things: > > > > > "n" == "y" > False > True == False > not True > "" > [] > > > If this makes no sense, please just say. > > > > if (customer == 2): > > > > > > Again, if you've done my changes from above: > > > > if not customer: > > > print("Welcome to the Star Wars Memorabilia Shop!") > customer = eval(input("Is there a customer in line? (1 = yes, 2 = > no)> ")) > > > > Again: > > > > > customer = input("Is there a customer in line? [Y/N]> ").lower() > > customer = (customer == "y") > > > BUT HOLD ON! > > > Run your program and then answer "2" twice. What happens? It's not good. > > > > > The problem is that answering "2" to this second one doesn't skip the loop! > > > x = ASK > LOOP: > if not x: > ASK > if x: > > > STUFF > MORE STUFF > > > Where you want: > > > > x = ASK > LOOP: > if not x: > ASK > if x: > STUFF > > > MORE STUFF > > > or (even better): > > > while not x: > x = ASK > LOOP: > STUFF > MORE STUFF > > > The second is what I've just decided to call the "ask-until-yes" model. > Basically, you ask until you get a "yes", so you don't have to put the loop > anywhere else. By the time the first loop is over, you *know* that x is True! > > > > elif (customer == 1): > > > > > > > Again, if you've done my changes from above: > > > > elif customer: > > > print("Please select an item to update your order and any other > number to check out.") > print("Yoda Figure: $10 each.") > print("Star Wars Movie DVD: $20 each.") > > > print("Death Star Lego Set: $200 each.") > print(" 1 for Yoda Figure") > print(" 2 for Star Wars Movie DVD") > print(" 3 for Death Star Lego Set") > > > order = eval(input("Order: ")) > > > > Again: > > > order = input("Order number: ") > > > if (order == 1): > > > If you've followed my advice: > > > if order == "1": > > > yoda = eval(input("How many Yoda Figures do you want? : ")) > > total = 10 * yoda > > > Ooookkay. Now you're thinking: "BUT *surely* I need eval here!!(?)". > > > You don't. > > > yoda = int(input("How many Yoda Figures do you want? : ")) > > > > > This is better because there are so many problems with eval, and int also > means that you can only order whole numbers of yodas. > You probably also want to call this "number_of_yodas", because you're not > defining what "yoda" is. > > > print("Total:", total) > > print("Current order:", yoda, "at", total) > > if (order == 2): > > > > > > If you've followed my advice: > > > if order == "2": > > > movie = eval(input("How many Star Wars Movie DVDs do you want? : ")) > > total = 20 * movie > > > As above: > > > number_of_movies = int(input("How many Star Wars Movie DVDs do you want? : ")) > > total = 20 * number_of_movies > > > > print("Total:", total) > > print("Current order:", movie, "at", total) > > if (order == 3): > > > > > > If you've followed my advice: > > > if order == "3": > > > legos = eval(input("How many Death Star Lego Sets do you want? : ")) > > total = 200 * legos > > > > As above: > > > number_of_legos = int(input("How many Death Star Lego Sets do you want? : ")) > > total = 20 * number_of_legos > > > print("Total:", total) > > print("Current order:", legos, "at", total) > > > > > shop_again = input("Would you like to keep shopping? 'Y' for yes, 'N' for > no: ") > > > Again: > > > shop_again = input("Would you like to keep shopping? [Y/N]> ").lower() > > > > shop_again = (shop_again == "y") > > > print()print("Your order before shipping and discounts: ",total) > > print() > > print("Answer a trivia question for a discount!") > > discount = eval(input("On what planet did Yoda live when Luke Skywalker first > met him? 1) Earth 2) Dagobah 3) Pluto :")) > > > Again: > > > discount = input("On what planet did Yoda live when Luke Skywalker first met > him? 1) Earth 2) Dagobah 3) Pluto :") > > > > if (discount == 1): > > print("Sorry, that answer was wrong!") > > if (discount == 2): print("That's correct, you get a 10% discount!") > > if (discount == 3): > > print("Sorry, that answer was wrong!") > > > If you've taken my advice: > > > if discount == "1": > print("Sorry, that answer was wrong!") > > > if discount == "2": > print("That's correct, you get a 10% discount!") > if discount == "3": > print("Sorry, that answer was wrong!") > > > print() > > if (discount == 2): > > > If you've taken my advice: > > > > if discount == "2": > > > > (total * .9) > > > Hold on! What do you think this line does? What is it meant to do? > > > You meant: > > > total = total*.9 > > > Which for clarity should be written: > > > > > total = total * 0.9 > > > > print("Your total before shipping: ",total) > > print("1) Regular Shipping: 3-4 business days, $5.00 per $50 ordered. 2) > Express Shipping: overnight, $10 per $50 ordered. 3) Super Saver Shipping: > 7-10 business days, free.") > > shipping = eval(input("Please select the shipping method you want: ")) > > > > > Again: > shipping = input("Please select the shipping method you want: ") > > > > if (shipping == 1): > > > > If you've taken my advice: > > <br... > Show original -- http://mail.python.org/mailman/listinfo/python-list
