Shopping List (Solution)
00:00 Here we are in IDLE. I’ve pasted just the tasks into this IDLE session just so I am going to remember what are the actual strings that I need to add and which methods am I supposed to use to do it.
00:13
And the first one was to create a list named food
with two elements, "rice"
and "beans"
. I’ll start my food
list by opening up and closing the square brackets and then putting two string elements in there.
00:25
The first one is "rice"
and the second one is "beans"
. I’ll separate them with a comma and like I said before, surrounded with square brackets.
00:34
And then I’ve got my food
list looking good. type(food)
is list
. That doesn’t sound too tasty. Anyway, let’s keep working on this shopping list.
00:46
I should append the string "broccoli"
to the food
list using the .append()
method. So I will say food.append()
and then pass in an object.
00:55
And this is going to be the object to add and that should be the string "broccoli"
.
01:03
Enter, and then the food
, wait, got to not add a plus here. The food
list now contains "rice"
, "beans"
, and "broccoli"
.
01:13
Next step is to add the strings "bread"
and "pizza"
using the .extend()
method. So we’re at this task right now. So I will say food.extend()
01:25
and then I can pass in an iterable here as it’ll nicely tells us here. So I will need another list, or it could be a tuple as well. But I’m going to use a list and I will add to that list "bread"
and "pizza"
.
01:42
So I create a new list element that contains two strings, "bread"
and "pizza"
. And I pass it as an argument to the .extend()
method that I’m calling on the food
object, pressing enter.
01:54
And looking at food
gives me the extended food
list. Now it contains "rice"
, "beans"
, "broccoli"
, "bread"
, and "pizza"
.
02:02
Next step is to print the first two items in the food
list using slice notation. I can do that by using the variable name food
, then opening up square brackets.
02:14 And then I want to print the first two items, which means I want to start at the beginning so I can omit the first index and just start with the colon that’s going to start slicing at the beginning.
02:24
And I’m going to go up to index two, which means that it’ll go up to, but not including, "broccoli"
. So we’ll get "rice"
and "beans"
, but "broccoli"
, which is at index two, is not going to be included anymore.
02:39
And these are the first two items of the list. So I get a list returned from slicing that contains the first two elements. And again, if you wanted to actually print that out from a script, you just have to pass it as an argument to the print()
function.
02:54
I’ll probably keep not using the print()
function because in here in the interactive IDLE shell, I can just inspect the output like this.
03:03
And then the last task here, print the last item in food
using index notation. So the last item, I can access it with negative indexing. So I can say food
, open up the square brackets, and then pass in the index -1
, which gives me the final element in the list.
03:22
And that is "pizza"
. All right, that’s the shopping list. Sounds like a relatively healthy meal. I would say just make sure you get a good pizza.
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