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Let's experiment with the code a little bit now so that you get a better understanding of certain aspects

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of Python.

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I want to focus here on the full loop.

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The for loop iterates over the to do lists and accesses the index and the item in each iteration.

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It constructs a string and it prints out that string in each iteration.

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Now, if I press enter here and then I press backspace to go one indentation level back at this point.

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Same level with for loop.

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And if I say print index comma item, what do you think we're going to get?

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And also I would like to print out.

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Hello.

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Before that.

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So let's see.

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I'm going to run this ad A to do clean the keyboard because it has to be clean sometimes.

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Add the new one.

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The monitor as well.

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And a third one add.

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Buy grocery press, enter press show and let's look at the output.

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So perhaps you guessed what we're going to get.

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So we get to clean the keyboards, clean the monitor, buy grocery.

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All these three are produced by the print row line in here, this one.

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And then we have this third line here to buy grocery.

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So that is produced obviously by this line we get or print out.

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And then we get to.

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Because index is too and item prints out by grocery.

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So why did I do this experiment?

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Well, this was to show you that once the loop ends, which is the case when you indent the loop, as

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we did here, then these are still variables.

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Index and items are still variables.

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And index has as a value of the last index in the for loop.

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And the same goes for item item.

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The variable will also have as value the last item of the whole of the list.

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So the loop went over and over again.

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Index was for zero.

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In the second iteration was one, in the third was two.

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And so once there were no more items in the loop, we get index assigns the final number, the final

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value of two and the same goes for item.

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So I hope that gives you some perspective to understand the for loop better.

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The index particularly could be used if you want to calculate the length of the list.

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So basically you would say length is

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index plus one, so that would print out the length A's and index plus one, which would be two +13.

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So we would get the length is three.

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Or you could also use a knife string if you like.

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So f length s and you'd have to put this inside curly brackets and close the string with a quote.

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So let me run this and to do one add to the to show and we get length is to.

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However, getting the length like this is quite a workaround.

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I would even call it a hack because calling it a workaround is giving it too much credit.

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The actual way to get the length of lists is by using another more appropriate function, and that is

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the length function.

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It's a function as argument.

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It gets the list and the length function doesn't even need a full loop.

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So if you wanted to show the length, all you'd have to do is like that.

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Run at 2 to 1 at two, the two show and you get two.

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So that is the output of the length function.

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So anyway, we don't need the length in this app, so I'll just delete everything and keep the loop

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as it was before.

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An experiment now over the enumerate method if you open the python console.

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And you do for I item or I j whatever you like.

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So I will s above the index.

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J is about the item itself.

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It doesn't matter what variable names you use in enumerate.

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Hello.

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Great.

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I and J execute.

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And this is what you get.

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So strings can also be used with the enumerate function because strings also are sequences of items

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and each item is itself a string.

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So each character of the string is a string itself.

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That's why we get here.

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We get zero in the first iteration.

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H So G prints out.

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H, Then we get one E and so on.

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So that's something to keep in mind.

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Now you know that functions return and output, right?

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And this here is a function.

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So what is the output of this function anyway?

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Or let's try a list as we did before.

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So let's say A, B, and C.

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And if we check a, we get this.

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So that's a bit confusing.

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The reason we get this is that the enumerate function returns an enumerate object.

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So just like we have list object types, we have strings object types, we have integers for numbers.

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We also have this strange object here.

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The difference here is that Python doesn't know how to display this object.

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The object actually contains delta, but you cannot see them.

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So it is not designed.

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The object itself is not designed to display those data in the command line.

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But if you use a popular type such as the list and you place that object in a list, so to basically

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to convert it into a list, you press enter and you get this.

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So now we have a representation of that enumerate object.

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This is actually the internal construction of that object.

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But now we can we can visualize it using a list, we can see it.

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So it's a list made of tuples.

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That is the first of all, the second tuple and the third tuple.

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Each tuple contains the index and the item itself of the original list.

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The index of B and the B itself.

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Index of C and the C itself.

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So actually when we do four or four item, whatever you call them in enumerate and you have that list

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here, ABC, what you're actually doing is you're doing this for item in.

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This list.

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So enumerate is a list of tuples and you say print I item press enter, enter and we get this.

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So actually I is getting the first item of the first simple and then item is getting the second item

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of that first sample.

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And we print them out here and we do the same for the other tuples.

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So that's about the innumerate object.

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Of course, you can do the same with a string.

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So hello.

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And you can convert it into a list.

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Sorry, I did the typo here.

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And you may rate.

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So be is an enumerate object.

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We can convert it into a list.

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And now we see that same construction.

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However, if you are thinking of converting of of be a numerous object into a string, you'll get a

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bit disappointed because all this will do is just convert that representation to a string.

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You see, it has quotes now.

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In other words, STR doesn't do what you intend to do.

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It's actually useless here.

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It is useless because the anatomy of an enumerate object would not be able to represent using a string

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because a string is just made of character of strings and at least can be made as you see, can be made

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of other tuples and other lists or other items, strings, numbers.

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That's why it is possible to convert enumerate into a list.

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And that was a series of experiments on the for loop and the enumerate object.

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Thanks a lot.