1
00:00:00,570 --> 00:00:01,440
Welcome back.

2
00:00:01,440 --> 00:00:07,620
We just learned about modules but let's say our project is getting even bigger.

3
00:00:07,620 --> 00:00:09,040
We have this main file.

4
00:00:09,060 --> 00:00:10,420
We have some utility.

5
00:00:10,520 --> 00:00:20,450
But let's say that we're now working for Microsoft and we have a new let's say shopping functionality

6
00:00:20,490 --> 00:00:25,900
an entire let's say shopping area where you can buy Microsoft T-shirts.

7
00:00:25,950 --> 00:00:33,850
Well we can now create a folder so we can add folders to our project and inside of this folder.

8
00:00:33,900 --> 00:00:42,950
Let's say we have a new file and we'll call this the shopping cart.

9
00:00:43,140 --> 00:00:47,280
Dot pi.

10
00:00:47,320 --> 00:00:53,350
So now this shopping cart dot pi is a folder in our project.

11
00:00:53,350 --> 00:00:55,790
You see that our project is getting bigger and bigger.

12
00:00:55,870 --> 00:01:03,970
And let's say that here we just have a function called by and we give it an item and let's say here

13
00:01:03,970 --> 00:01:09,750
we we have a cart variable that let's say adds.

14
00:01:09,840 --> 00:01:14,840
It's not a very sophisticated buying system but for our example it should be fine.

15
00:01:14,850 --> 00:01:19,300
And then we just return the cart now.

16
00:01:19,330 --> 00:01:26,530
In here we have this by function and let's say in our main file.

17
00:01:26,530 --> 00:01:33,580
So up here we want to also import our shopping cart by function.

18
00:01:33,670 --> 00:01:42,150
How can we do that well if we tried to do shopping cart like this.

19
00:01:42,150 --> 00:01:45,890
Remember that's the name of our file.

20
00:01:46,000 --> 00:01:50,070
You see that I get an underline it says imported but unused.

21
00:01:50,100 --> 00:01:50,460
OK.

22
00:01:50,560 --> 00:01:51,970
So does that mean I can use it.

23
00:01:52,000 --> 00:01:53,080
Let's see.

24
00:01:53,080 --> 00:02:01,930
Most say shopping cart and if I click Run module not found error no module named shopping cart.

25
00:02:02,160 --> 00:02:13,100
You see what we've created here is what we call a package a package is simply a folder and we learned

26
00:02:13,100 --> 00:02:22,550
about module which is these files these Python files a package is a level up a package is a folder containing

27
00:02:22,760 --> 00:02:27,720
modules so you can have a package with multiple modules inside of them.

28
00:02:28,280 --> 00:02:37,670
So this shopping cart is a module but this shopping is a package so the way it works when we import

29
00:02:37,850 --> 00:02:41,510
from a package is we say the package name.

30
00:02:41,510 --> 00:02:46,800
So what's the package name it's shopping.

31
00:02:47,040 --> 00:02:58,600
And then we do a dot so dot shopping cart so package name and then the module name.

32
00:02:58,610 --> 00:03:01,130
Now if we do this let's see if this works.

33
00:03:01,250 --> 00:03:05,960
Let's say I do shopping dot shopping cart.

34
00:03:05,960 --> 00:03:09,510
Now if I print this let's make this a little bit smaller

35
00:03:12,340 --> 00:03:13,230
All right.

36
00:03:13,560 --> 00:03:20,280
Now I have access to the shopping cart module by importing the package shopping which is the folder

37
00:03:20,500 --> 00:03:28,890
and in the shopping cart a you notice once again we have a PI cache that was created for the shopping

38
00:03:28,890 --> 00:03:33,960
cart so let's see if we can use the BI function.

39
00:03:34,000 --> 00:03:42,940
So I'm going to say bye and then item I'll say I'm buying it just an apple if I click Run.

40
00:03:42,960 --> 00:03:43,530
There you go.

41
00:03:43,530 --> 00:03:49,300
I get my apple list and I was able to imported from a package.

42
00:03:49,540 --> 00:03:56,560
Now here's the thing I want to try and copy what we've just done into a real life scenario instead of

43
00:03:56,560 --> 00:04:01,090
using this Web site old Dot I.T. let's actually create our own project.

44
00:04:01,300 --> 00:04:07,150
I'm going to use pi Char and I recommend you use pi chairman's Well just for these next couple of various

45
00:04:09,090 --> 00:04:15,400
let's open up by picture and let's just create a new project here.

46
00:04:15,430 --> 00:04:17,290
Now we can call it whatever we want.

47
00:04:17,290 --> 00:04:19,780
So let's just call it modules for now.

48
00:04:19,780 --> 00:04:22,170
For our project you can see where it's being saved.

49
00:04:22,390 --> 00:04:26,890
And remember here we get to pick what interpreter we want.

50
00:04:26,890 --> 00:04:30,330
We're going to talk about this virtual and later on in the videos.

51
00:04:30,460 --> 00:04:35,620
But the key thing is to make sure that our base interpreter is using Python 3.

52
00:04:35,980 --> 00:04:40,930
In my case the Python 3 that we've downloaded and user user local.

53
00:04:41,200 --> 00:04:46,770
If you're on a Mac or Linux if you're on Windows this path will probably be different.

54
00:04:46,780 --> 00:04:49,120
Now we can just create a project

55
00:04:53,120 --> 00:04:57,050
and we see here we have our modules project.

56
00:04:57,280 --> 00:05:01,770
Now we're going to ignore all these folders for now we're going to talk about them later on.

57
00:05:01,810 --> 00:05:05,560
The key here is that we want to create a new file.

58
00:05:05,890 --> 00:05:10,720
I'm going just right click here and say new

59
00:05:14,420 --> 00:05:23,720
and we can just call it let's say main dot pi and notice here that I created in a folder called V and

60
00:05:23,710 --> 00:05:24,120
V.

61
00:05:24,210 --> 00:05:25,560
We'll get back to that shortly.

62
00:05:26,340 --> 00:05:30,960
Now let's make this a little bit bigger so we can see and we're going to copy whatever we've just done

63
00:05:31,140 --> 00:05:32,170
here.

64
00:05:32,340 --> 00:05:33,900
So I'm going to copy

65
00:05:36,700 --> 00:05:40,430
the main file like this that did not copy.

66
00:05:40,430 --> 00:05:41,200
Let's try that again

67
00:05:45,090 --> 00:05:53,700
like that and then we're also going to create a few more files so we'll create a folder so in here.

68
00:05:53,740 --> 00:05:55,270
I'm just going to say right click.

69
00:05:55,360 --> 00:05:58,540
Say New in right away.

70
00:05:58,540 --> 00:06:01,140
You see that it says Python package.

71
00:06:01,360 --> 00:06:08,960
I'm going to click on Python package or I can create a director if I want as well and when I click here

72
00:06:09,080 --> 00:06:15,540
let's name the package like we've done here as shopping all right.

73
00:06:15,550 --> 00:06:21,490
We get our shopping folder and in here let's right click.

74
00:06:21,500 --> 00:06:27,010
Say new new file and we will call this the shopping cart dot pie.

75
00:06:27,020 --> 00:06:33,110
So shopping cart dot by.

76
00:06:33,180 --> 00:06:35,950
And then finally we'll add our utility file.

77
00:06:36,050 --> 00:06:39,670
You know we're doing a lot but hey I'm trying to prove a point here.

78
00:06:39,670 --> 00:06:42,030
Trust me this is gonna be important.

79
00:06:42,070 --> 00:06:44,270
So utility dot pie.

80
00:06:44,320 --> 00:06:45,160
There we go.

81
00:06:45,160 --> 00:06:47,660
So we have the same setup that we have here.

82
00:06:47,710 --> 00:06:49,050
Let me copy this over as well.

83
00:06:52,290 --> 00:06:53,420
All right.

84
00:06:53,550 --> 00:06:58,400
And we copy let's make this bigger like that right.

85
00:06:58,580 --> 00:07:06,470
So we have our files just like we have in our Repsol except this time we're actually using an IDC.

86
00:07:06,650 --> 00:07:13,400
Now the reason I wanted to transfer over to the IDC is that there's an extra file here that we didn't

87
00:07:13,400 --> 00:07:19,430
see in the repo and the repo actually hides this away from us.

88
00:07:19,460 --> 00:07:24,290
You see this underscore in it dot pi far and it's completely empty.

89
00:07:24,350 --> 00:07:26,190
There's nothing in here.

90
00:07:26,270 --> 00:07:34,400
One of the rules of a package of a python package is that on the root of this package you have to have

91
00:07:34,400 --> 00:07:38,990
an underscore underscore in it underscore underscore dot pi.

92
00:07:39,000 --> 00:07:47,090
Now why is that well because the interpreter is going to read this and say oh this is a python package.

93
00:07:47,510 --> 00:07:53,630
Remember how when I right click here I said new and then I had an option of a directory or a python

94
00:07:53,630 --> 00:07:59,170
package by clicking Python package it automatically added this in it for us.

95
00:07:59,180 --> 00:08:04,000
So although here everything worked without a net.

96
00:08:04,250 --> 00:08:07,470
This is just something that reptile hides underneath the hood.

97
00:08:07,480 --> 00:08:13,700
Anytime you want to create a package you'll see that we need to have an Internet file and it can just

98
00:08:13,700 --> 00:08:16,110
be completely empty now.

99
00:08:16,140 --> 00:08:22,000
The beauty here with pie chart is that it does it for you which is really really nice OK.

100
00:08:22,010 --> 00:08:25,360
So let's run this code and make sure that it still works.

101
00:08:25,370 --> 00:08:28,190
So this is our main dot pie.

102
00:08:28,280 --> 00:08:38,450
I can simply run the code here by going to run and then selecting run let's run our main file and we

103
00:08:38,450 --> 00:08:39,170
get an error.

104
00:08:39,200 --> 00:08:40,700
Let's zoom in here

105
00:08:43,810 --> 00:08:51,190
and we see that module shopping does a shopping cart has no attribute buy and that is because we did

106
00:08:51,190 --> 00:08:52,990
not import the BI function here.

107
00:08:53,110 --> 00:08:54,400
So let's do that.

108
00:08:54,430 --> 00:08:57,740
Let's go to shopping cart buy.

109
00:08:57,820 --> 00:09:04,470
Make sure I copy that paste it in let's zoom that in.

110
00:09:04,480 --> 00:09:10,730
And by the way I'm zooming here on my touchpad I can just use two fingers to zoom in here if I click

111
00:09:10,740 --> 00:09:16,860
run again and this time once you ran it once you can just click on run again and there we have it.

112
00:09:16,930 --> 00:09:21,000
We have apple right here as the output.

113
00:09:21,430 --> 00:09:27,280
And it says process finished with exit code 0 in programming when something exits with code 0 it means

114
00:09:27,400 --> 00:09:28,660
there were no errors.

115
00:09:28,660 --> 00:09:29,560
If you get one.

116
00:09:29,590 --> 00:09:32,220
Well that's usually an error.

117
00:09:32,230 --> 00:09:34,580
All right so we have everything working.

118
00:09:34,580 --> 00:09:38,090
And this is now our setup.

119
00:09:38,090 --> 00:09:40,630
We have our main file.

120
00:09:41,000 --> 00:09:47,540
We have our other modules like utility and then we also have our packages and their packages because

121
00:09:47,540 --> 00:09:54,290
they have this init file and we have different modules into and as projects get bigger and bigger and

122
00:09:54,290 --> 00:10:02,300
we use ideas like Pi charm we organize our functionality our grouping into these packages and modules

123
00:10:03,260 --> 00:10:10,850
and really really good developers are able to organize code in really nice packages that makes sense

124
00:10:10,880 --> 00:10:13,530
really nice modules that make sense.

125
00:10:13,700 --> 00:10:16,480
And this is a skill that is really hard to teach.

126
00:10:16,490 --> 00:10:22,000
It just comes with practice by looking at other people's projects by working on projects.

127
00:10:22,370 --> 00:10:29,300
But the key thing is that you want to do what makes sense and when we start working on some of our final

128
00:10:29,300 --> 00:10:34,460
projects we have over 10 projects coming up that we're going to work on now with those ones.

129
00:10:34,460 --> 00:10:38,410
You're going to start to learn different ways to organize code as you follow along.

130
00:10:38,420 --> 00:10:40,800
So don't worry.

131
00:10:40,880 --> 00:10:44,720
Let's take a break and explore modules a little bit more in the next video.