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Hi.

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Welcome back.

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In this video, we will create a simple program.

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We will start with this list, and then we will create a program which outputs this three lines here.

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So the program will sort of the items alphabetically, as you see, Ben is the first one, John.

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And then comes son.

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And we will also place a number before each of the items here in the output.

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So let's do that.

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How can we do this?

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So you see that this is an iterative operation.

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So we're doing the same thing over and over again.

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So naturally you think of four loops on here.

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We we're not simply printing out the items, but also the indexes.

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So you start thinking about accessing the indexes with the enumerate function.

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Therefore we need something like four index item in enumerate waiting list.

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Then we want to construct the string, perhaps the row.

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So it's an F string.

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It's going to have a variable, which is the index.

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And then after the index we have a dot, dot.

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And then another variable, which is the item.

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Not that items should be capitalized.

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So let's add a dot capitalized method here.

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So it is possible to add expressions inside these curly brackets and not only variables.

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And then if you print out rho and you run the scripts.

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You're going to get this zero, send one band to John.

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So we need to change 0 to 1.

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To do that.

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You can just add one.

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And all the indices will be shifted by one.

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So now we have one, two, three.

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But the items are not sorted alphabetically.

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So how can we sort a list?

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How do we handle this?

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Where do we go to find a way to sort lists where the first thing to go to is to check their list to

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see if there is a method that modifies the list?

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So just scroll and it seems there exists a method.

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So perhaps salt is the answer here.

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So if you check help list that sort, you see that it's sort of the list in ascending order and returns

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none.

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So all we have to do is point to the variable that holds the list and then to the source method.

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And don't forget the parentheses.

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If I execute the script now, you'll see that Ben will be the first one, followed by John, followed

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by son.

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So the items are sorted alphabetically, successfully.

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As you can see, we didn't have to assign.

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And you variable to the list because as I explained you in the previous video lists are mutable.

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That means the methods will mutate the list.

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So the method itself doesn't return anything you see here.

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Return none.

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So the method doesn't return a list in the case of strings string methods.

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They return the new string.

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So just to.

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Refresh your memory if you had like.

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Hello, Dot.

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Replace.

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So that's a method of a string.

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And you replace perhaps O with x, you press enter, you get hell X in return.

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So the replace method returns a string of both.

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If you have a list.

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Such as C, D, and B, and you say dot sort, you press enter, you get nothing as output.

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So the third method doesn't return anything.

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Otherwise we would have seen that output here in the console.

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Now the list itself is solid and it is somewhere floating in this interpreter session and we cannot

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access it because we didn't assign it to a variable.

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So if you wanted this list to be accessible, you'd want to force assign it into a variable.

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Such as.

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My list is equal to that.

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And then you say my list.

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So again, no output is generated because the lists are mutable and the sole method doesn't return a

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note, which both my list has now been sorted.

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So B is the first letter, C is the second, and D is the last one.

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And lastly, how do you sort the list in descending order?

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Well, you can see the health file and you will see that there is a reverse equal to false argument.

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That means if you say reverse equals to.

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True.

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And you check my list.

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You're going to see that D is the first one, followed by C, followed by B.

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So by default the reverse is false, which means the list will be sorted in ascending order alphabetically.

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And that was the example for today.

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Thanks a lot.