1
00:00:00,850 --> 00:00:01,890
Welcome back.

2
00:00:01,900 --> 00:00:05,970
Let's talk about our next data type and it's a big one.

3
00:00:06,070 --> 00:00:09,830
A very very useful one.

4
00:00:09,840 --> 00:00:18,290
It's called list and list is an ordered sequence of objects that can be of any type.

5
00:00:19,800 --> 00:00:22,820
So you can think of them as strings right.

6
00:00:22,830 --> 00:00:30,750
We had strings previously that we learned about except that each sequence of this string well was was

7
00:00:30,750 --> 00:00:36,310
a string was a letter or a number wrapped in quotation marks lists.

8
00:00:36,320 --> 00:00:39,410
On the other hand looks something like this.

9
00:00:39,620 --> 00:00:47,810
Let's say we create a variable ally and list we denote with square brackets and inside of these square

10
00:00:47,810 --> 00:00:50,660
brackets we can have different objects.

11
00:00:50,660 --> 00:00:55,300
So for example we can have one two three four five.

12
00:00:55,340 --> 00:01:07,820
We can also have let's say ally 2 AND THIS IS GOING TO HAVE A B C and it can have any collection of

13
00:01:07,820 --> 00:01:17,690
items that we want we can even mix and match and say that we have one two then a then maybe even the

14
00:01:17,690 --> 00:01:30,370
Boolean value true so all of these are lists now lists are extremely important and in other programming

15
00:01:30,370 --> 00:01:35,010
languages you might have heard the word arrays.

16
00:01:35,170 --> 00:01:43,440
So in Python lists are a form of array and later on when we get into the modules section of the course

17
00:01:43,740 --> 00:01:50,220
we will talk about the difference between lists and arrays but if you are coming from a different programming

18
00:01:50,220 --> 00:01:59,760
background then lists are like arrays in your language a collection of items Now the neat thing about

19
00:01:59,760 --> 00:02:04,880
lists is that it's the first data structure that we're learning now.

20
00:02:04,950 --> 00:02:08,430
What is a data structure.

21
00:02:08,430 --> 00:02:12,720
Data structure is a very important concept in programming languages.

22
00:02:12,720 --> 00:02:22,590
It's a way for us to organize information and data into let's say a folder or a cupboard or a box so

23
00:02:22,590 --> 00:02:27,240
that these data structures can be used with different pros and cons.

24
00:02:27,240 --> 00:02:34,200
For example you have a fridge where you store your food and fridges are really really good at putting

25
00:02:34,380 --> 00:02:41,010
your food inside keeping it cold and then taking it out or you might have a backpack a backpack is really

26
00:02:41,010 --> 00:02:45,870
really good to stuff everything in there but when you're looking for things in a backpack it's really

27
00:02:45,870 --> 00:02:46,520
really hard.

28
00:02:46,890 --> 00:02:54,090
So you can think of data structures similar to that a container around your data that has different

29
00:02:54,090 --> 00:02:56,470
pros and cons of accessing that data.

30
00:02:56,490 --> 00:03:02,230
Removing that data writing data but that's something we'll get into a little bit later.

31
00:03:02,250 --> 00:03:10,920
The key here is that the square brackets allow us to contain information and data like strings integers

32
00:03:11,160 --> 00:03:15,730
floats if we want to bullying us into a contained fashion.

33
00:03:15,870 --> 00:03:17,850
So let's think of a good example here.

34
00:03:17,880 --> 00:03:25,950
What if we had a shopping cart let's say where Amazon here and then Amazon has the Amazon shopping cart

35
00:03:26,600 --> 00:03:29,590
and then here we can collect different things that we want.

36
00:03:29,760 --> 00:03:31,710
Maybe we collect some.

37
00:03:31,710 --> 00:03:34,470
I don't know notebooks and you know what.

38
00:03:34,530 --> 00:03:39,380
Let's get some gadgets let's get some maybe some sunglasses.

39
00:03:39,600 --> 00:03:47,990
We can add different items here different strings different data into this cart and now just like we

40
00:03:47,990 --> 00:03:53,750
saw in strings we can access the Amazon cart in different ways.

41
00:03:53,770 --> 00:04:02,230
For example I can access it again with square brackets and simply say I want to item zero so fine print

42
00:04:02,230 --> 00:04:07,760
here and do Amazon cart look at that.

43
00:04:07,800 --> 00:04:08,910
I get notebooks.

44
00:04:08,910 --> 00:04:14,520
The second item I get sunglasses.

45
00:04:14,580 --> 00:04:16,140
What about the third item

46
00:04:18,990 --> 00:04:20,370
no list.

47
00:04:20,430 --> 00:04:25,070
Index out of range but this should make sense now.

48
00:04:25,100 --> 00:04:31,150
This is a list where we're accessing the index of but it only contains two items.

49
00:04:31,150 --> 00:04:35,790
So if we're going 0 1 to the third item nothing exists.

50
00:04:35,800 --> 00:04:39,000
So our program says if that doesn't work you're doing something wrong.

51
00:04:40,300 --> 00:04:47,530
And just like strings these list items are in memory in their separate bookshelf.

52
00:04:47,530 --> 00:04:49,500
Right but one right next to each other.

53
00:04:49,510 --> 00:04:52,960
So we can go 0 1 2 3 4 5.

54
00:04:52,990 --> 00:04:56,210
So on and so forth until the list ends.

55
00:04:56,410 --> 00:04:56,870
All right.

56
00:04:56,920 --> 00:05:00,810
Let's learn about lists a lot more in the next video by.