On 23/05/17 18:38, Rafael Knuth wrote: > Now, I want to print the item next to the stock update, and I am > receiving an error message. I couldn't figure out how to fix that:
So show us the error message, all of it. I can't begin to guess what it might be. UI also don't understand what "print the item next to the stock update" means. Do you mean the actual location of the data in the printed string? Or do you mean the value(which?) next to the one in your function? Can you show us some examples? > def shopping(quantity, price, stock): > total = 0 > for key, value in quantity.items(): > total += quantity[value] * price[value] > stock_update = stock[value] - quantity[value] I don't see how this would work. value is the value from the dictionary which is an integer. But you are using it as a key which should be a string? So in your first iteration key,value will be key = 'bapple', value=10 so you are trying to evaluate stock[10]-quantity[10] but thee are no such items. I suspect you mean: stock['bapple'] - quantity['bapple'] or in your function: stock[key] - quantity[key] But in that case you don;t need the value from items() you can just iterate over the keys: for item in quantity: ... stock_update = stock[item] - quantity[item] print(item, stock_update) > print(key, stock_update) > print(total) > > quantity = { > "bapple": 10, > "banana": 20 > } > > price = { > "bapple": 5, > "banana": 3 > } > > stock = { > "bapple": 20, > "banana": 30 > } > > shopping(quantity, price, stock) I'm not clear on what these variables indicate. What is the difference between quantity and stock? Also this might be a good time to look at classes and objects. You could avoid all the multiple stores by putting the various data elements in a class. This would avoid the potential headaches caused by mis-typing the item names in each store, for example. You could then have variables bapple and banana and access, for example, bapple.quantity and bapple.price. And just keep a simple list of items. Just a thought... -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ http://www.amazon.com/author/alan_gauld Follow my photo-blog on Flickr at: http://www.flickr.com/photos/alangauldphotos _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor