Name: Pythonでのリストの紹介 (Pythonチュートリアル #4) (Introduction To Lists In Python (Python Tutorial #4))
Uploaded: 2021-01-14T10:22:19.000Z
Duration: 9 min 55 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

So in this video, I'm gonna introduce you to lists in Python.

程度の副詞

The list is a type of data, just like strings and integers that we've seen so far on its used to store a list of things, and it's similar to a raise in some other languages, like Java.

So let's take a look at one example here to define a list you can just write a eco's open scar bracket.

Three comma tang comma minus one close square brackets on this line means define a new list with the elements 3 10 on minus one on assigned this list to this viable eight.

And just a quick note here that you can download this simple file by going to see a snow that io slash python for.

On another quick reminder that you don't necessarily have to use Jupiter.

You could use, for example, part charm, which is a good idea.

Once we run the cell, A should be defined, so let's print a with print.

Prentice is a and we see that we get a list with the elements.

What if we wanted to add an item to this list?

You can do that with a dot upend parentheses.

So this dot notation is a pretty common one on you.

So this function a pen is basically a predefined function that you can use on the list data type.

So again, that's a dot a pen parentheses.

Once we print A, you see that the number one has been added to this lists.

So one interesting thing about the Python list, which is different from some other languages like Java, is that you can mix types in a single list so you could have a list containing numbers as well as a string.

Let's see how that works by a pending the string Hello to the list A ways.

A duck, a pen, parentheses, double quotes.

Execute this so and you see that this list now contains hello.

The string, as well as the numbers lists, could even contain another list.

So this maze create a newest with the Elements one and two, and they appended to this list.

Francis is a Let's run this cell and now you see that we have a bunch of numbers and then string, which is hello on another list within this single list.

Okay, what if you wanted to delete on items from this list, for example, that last item to delete the last item you can do a dot pup Prentice's.

Here on pop is another function that's predefined for the lists data type.

And that's why we can just write a dark pop open currencies close, parent sees, and to see the result.

You can, of course, print a Let's run this so and you see that a now has the numbers on the string, but not the list, because that's popped or deleted.

This hello strength with Ada Pup, which do It's the last item off the list, of course, And then let's print a and you see that it now has numbers on Lee.

Now, there are many other predefined functions other than pop.

There a type but a pen on pop are two of the most common ones.

Okay, What if you wanted to retrieve a specific item from this list?

For example, the first item, the second item or the third item.

To do that, you can just write a scar buckets zero.

And this means retrieved the item from the list A with the index there on in python, just like in many other languages.

So the first item in the list has the next era on the second item has the next one.

The third item has the next two and so on.

Okay, so we want to print this item just to make sure we got the right one.

You don't have to use the print statement every time you could just write a scar buckets they're here on.

When you run this cell, you get the first item in the lists.

But to keep it consistent on also to make sure it works in any other platform.

I'm gonna use the prints they meant every time.

What if you wanted to retrieve the fourth item?

To do that, you can just do a score buckets.

And then let's prints that on, we get one.

And what if you wanted to change the content of this list?

So what if you wanted to change this number 3 to 100?

To do that, you can first select that item with a score.

And then you can assign a new number or any new value to it with a scar pockets there.

Let's print a again with print princess, eh?

And you see that the first value of this list is 100 now instead of three.

Okay, Now I'm gonna give you a quick exercise problem to practice where you have learned so far.

Let's say you have a list with three strings inside.

So you have b equals square brackets, double quotes, banana comma, double coats, apple comma and then Microsoft.

Can you swap the first value off this list?

Who's index is off course zero with the last item off this list.

Before I show you my solution to this problem, I'm gonna show you a model you can use for thinking about a list in Python when you have B equals banana Apple, Microsoft.

The way you can think about it is that B is going to be sort of like three boxes put together or one giant box, one long box with three compartments.

And each of those compartments acts like a variable, so each of those refers to a value.

We're first to banana, and the second element refers to Apple.

And the third element, of course, refers to the string Microsoft on.

I'm gonna show you my solution first, right Temp Eco's Be Square bug.

So we're defining a new viable called temp for a temporary viable, which is going to refer to what be square bracket zero refers to, which is this one.

And then you can write B square bracket zero eco's be scar buckets, too.

So we're saying the first compartment should now refer to whatever the third compartment refers to because, like I said, the index for the first item is zero on the index for the second item is one on the index for the third item is too.

So after this line, the first compartment or the first element will now refer to what the third compartment refers to, which is Microsoft.

And once you have that you can write, be score buckets to equals.

Temp on the third compartment now will refer to what temp refers to, which is banana.

As a result, after these pieces of code, we have the desired result.

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Pythonでのリストの紹介 (Pythonチュートリアル #4) (Introduction To Lists In Python (Python Tutorial #4))

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