1
00:00:00,700 --> 00:00:05,840
Okay, so looking at these, why don't
we go ahead and grab this one first?

2
00:00:05,840 --> 00:00:08,820
So as the user,
I should be able to confirm my order so

3
00:00:08,820 --> 00:00:12,500
that I do not accidentally purchase
more tickets than intended.

4
00:00:12,500 --> 00:00:16,700
And I wanna do that one because I know
that that's right after what we just did.

5
00:00:16,700 --> 00:00:19,360
We just showed them the price,
so let's prompt and

6
00:00:19,360 --> 00:00:22,725
see If they want to buy them, let's do it.

7
00:00:22,725 --> 00:00:25,000
So put that In Progress.

8
00:00:25,000 --> 00:00:26,610
Let's flip over here.

9
00:00:26,610 --> 00:00:28,030
So we just showed the total due.

10
00:00:28,030 --> 00:00:33,350
So let's come in here and let's ask
if they want to continue, all right?

11
00:00:33,350 --> 00:00:41,054
So we'll say Prompt user
if they want to proceed.

12
00:00:41,054 --> 00:00:45,998
And typically the way that you do that
in these console applications is you

13
00:00:45,998 --> 00:00:48,561
ask them for a Y or an N, for a yes or no.

14
00:00:48,561 --> 00:00:54,968
So we can do that, and then if they
answer that they do wanna proceed,

15
00:00:54,968 --> 00:01:00,720
so If they want to proceed,
we got a couple of things, right?

16
00:01:00,720 --> 00:01:02,810
So we need to branch out on that decision.

17
00:01:02,810 --> 00:01:04,960
So let's, how are we gonna mark this?

18
00:01:04,960 --> 00:01:05,510
Let's do it this way.

19
00:01:05,510 --> 00:01:07,080
I'll do this on separate lines.

20
00:01:07,080 --> 00:01:11,570
So if they want to proceed,
we're going to print out to the screen.

21
00:01:12,880 --> 00:01:16,070
Let's just print out SOLD!, so
that we can confirm the purchase cuz

22
00:01:16,070 --> 00:01:18,110
remember we're not gonna
process the credit card.

23
00:01:18,110 --> 00:01:19,600
So we'll say to confirm purchase.

24
00:01:22,000 --> 00:01:26,720
And because they did purchase it,
we need to decrement, or

25
00:01:26,720 --> 00:01:30,260
reduce by the number of tickets
that they actually bought, right.

26
00:01:30,260 --> 00:01:32,834
So let's see.

27
00:01:32,834 --> 00:01:36,388
And then decrement, or reduce by,

28
00:01:36,388 --> 00:01:42,230
the tickets remaining,

29
00:01:42,230 --> 00:01:45,890
by the number of tickets purchased.

30
00:01:48,050 --> 00:01:50,980
Cool, so that's if it did work.

31
00:01:50,980 --> 00:01:53,426
So, lets do that,
we'll give you separate line there.

32
00:01:53,426 --> 00:01:56,794
And then, of course,
we'll have our Otherwise.

33
00:01:59,419 --> 00:02:01,490
So, they wanna keep it friendly, right?

34
00:02:01,490 --> 00:02:06,200
So, let's just go ahead and
otherwise let's thank them by name,

35
00:02:06,200 --> 00:02:08,336
that sounds good.

36
00:02:08,336 --> 00:02:09,375
All right, so

37
00:02:09,375 --> 00:02:15,880
it sounds like some branching logic based
on their decision of Y or N, you got it?

38
00:02:15,880 --> 00:02:18,570
Now go ahead and
take these line by line, you got this.

39
00:02:18,570 --> 00:02:21,640
Check the teacher's notes and
use the forum if you get stuck.

40
00:02:21,640 --> 00:02:22,400
Ready?

41
00:02:22,400 --> 00:02:23,860
Pause me.

42
00:02:23,860 --> 00:02:25,160
Okay, all set?

43
00:02:25,160 --> 00:02:28,830
So here's what I did, I prompted again and
I was using input and

44
00:02:28,830 --> 00:02:33,145
I stored that in a variable called
should proceed pretty clear right?

45
00:02:33,145 --> 00:02:38,960
input ("Do you want to proceed?

46
00:02:38,960 --> 00:02:41,940
And I gave them a Y/N and
just wrote it there.

47
00:02:41,940 --> 00:02:43,196
Give a couple of spaces.

48
00:02:45,196 --> 00:02:48,560
And so that will come up and
they'll say yes or no.

49
00:02:48,560 --> 00:02:53,030
And so if they want to proceed,
so if should_proceed.

50
00:02:53,030 --> 00:02:54,640
Now something I did here.

51
00:02:54,640 --> 00:02:58,240
As I made, I'm checking the lowercase
version of should proceed.

52
00:02:58,240 --> 00:03:00,690
Just in case they entered a lowercase y or
a capital y.

53
00:03:00,690 --> 00:03:06,590
Either one, if either one of those is y,
right, lower.

54
00:03:06,590 --> 00:03:11,931
So, if y is equal to y,
we're gonna open up that body and

55
00:03:11,931 --> 00:03:16,377
we're gonna print that
to the screen SOLD!.

56
00:03:16,377 --> 00:03:20,684
And it looks like we are indented
too far here, aren't we?

57
00:03:20,684 --> 00:03:22,390
Let's go ahead and bring this back.

58
00:03:23,770 --> 00:03:25,210
Staring to feel a little awkward there.

59
00:03:27,060 --> 00:03:29,560
There we go.
So we're gonna print sold,

60
00:03:29,560 --> 00:03:33,140
and then we're gonna decrement
the tickets remaining.

61
00:03:33,140 --> 00:03:34,170
And you know what I'm gonna do?

62
00:03:34,170 --> 00:03:36,360
I'm gonna add a reminder here for us.

63
00:03:36,360 --> 00:03:38,682
I'm gonna put in a TODO.

64
00:03:38,682 --> 00:03:41,651
Spanish speakers sometimes
think that that means all.

65
00:03:41,651 --> 00:03:46,927
I've had worked with a few native Spanish
speakers and to do they think it's

66
00:03:46,927 --> 00:03:51,875
like to-do, like all, it means to
do like we're gonna do this later,

67
00:03:51,875 --> 00:03:56,340
so we're gonna gather credit
card information and process it.

68
00:03:57,750 --> 00:03:58,560
Awesome.

69
00:03:58,560 --> 00:04:02,010
And that's already on the Trello board,
we won't commit to completing it just yet,

70
00:04:02,010 --> 00:04:06,480
but I'm gonna leave this here so next time
we come into the code we know it's there.

71
00:04:06,480 --> 00:04:09,510
And now I'm gonna use in place
subtraction on tickets remaining,

72
00:04:09,510 --> 00:04:13,093
just like we've done in place addition,
you can also do it with subtraction.

73
00:04:13,093 --> 00:04:19,636
So tickets_remaining -= num_tickets,
right.

74
00:04:19,636 --> 00:04:24,981
So, that's shorthand for tickets remaining
= tickets remaining- num_tickets.

75
00:04:24,981 --> 00:04:27,442
Just using that -= for
in place subtraction.

76
00:04:27,442 --> 00:04:31,590
And so this Otherwise,
this is an else clause here, right?

77
00:04:31,590 --> 00:04:39,171
So else, we're gonna print,
otherwise were gonna thank them by name,

78
00:04:39,171 --> 00:04:44,820
and we'll print, well, Thank you anyways.

79
00:04:44,820 --> 00:04:48,190
Placeholder, and we'll format that.

80
00:04:48,190 --> 00:04:50,570
Pass on that name, close that up.

81
00:04:51,680 --> 00:04:54,280
Okay, I'm gonna save this,
and give it a run,

82
00:04:54,280 --> 00:04:56,635
let's see what mine looks like right now.

83
00:04:56,635 --> 00:04:57,526
How do you do?

84
00:05:00,139 --> 00:05:01,740
There are a hundred tickets remaining.

85
00:05:01,740 --> 00:05:02,540
What is your name?

86
00:05:02,540 --> 00:05:05,220
My name is Craig,
I would like to have 3 tickets.

87
00:05:05,220 --> 00:05:09,080
The total due is $30,
do you wanna proceed?

88
00:05:09,080 --> 00:05:10,270
No way.

89
00:05:10,270 --> 00:05:11,780
So it's not Y, right?

90
00:05:11,780 --> 00:05:12,690
So it says thank you anyway.

91
00:05:12,690 --> 00:05:13,640
So let's do the other one.

92
00:05:13,640 --> 00:05:18,290
My name is Craig, Crag, sure, and

93
00:05:18,290 --> 00:05:22,110
I wanna buy four tickets,
and do you wanna proceed?

94
00:05:22,110 --> 00:05:25,860
Yes as a matter of fact I do but
I lower case y, want to proceed.

95
00:05:25,860 --> 00:05:26,682
Sold.

96
00:05:26,682 --> 00:05:30,278
So I don't actually know if that
decrementing the tickets remaining

97
00:05:30,278 --> 00:05:33,821
actually worked but I think maybe
another ticket will get us there.

98
00:05:33,821 --> 00:05:38,660
So, let's flip back to
the Trello board real quick.

99
00:05:38,660 --> 00:05:39,990
Let's look over there.

100
00:05:39,990 --> 00:05:41,720
I think we're done with
this confirmation one.

101
00:05:41,720 --> 00:05:42,586
Nice job.

102
00:05:43,699 --> 00:05:44,823
Okay, so as a user,

103
00:05:44,823 --> 00:05:48,410
I should not be offered tickets
if there aren't any available.

104
00:05:48,410 --> 00:05:50,960
Let's move that over to In Progress.

105
00:05:50,960 --> 00:05:52,140
Awesome, and let's flip back.

106
00:05:53,920 --> 00:05:55,762
So, I think we can tackle this one but

107
00:05:55,762 --> 00:05:59,910
we're going to need to assume that
there's some sort of continuum, right?

108
00:05:59,910 --> 00:06:03,670
This code will continue to run until
there aren't any tickets left.

109
00:06:03,670 --> 00:06:08,370
So, let's see,
we want all of this code, right?

110
00:06:08,370 --> 00:06:12,010
We want all of this code that we wrote,
like from hereon down.

111
00:06:12,010 --> 00:06:13,951
We want that to go, right?

112
00:06:13,951 --> 00:06:18,808
Makes sense, so we want to run this code

113
00:06:18,808 --> 00:06:24,118
continuously until we run out of tickets.

114
00:06:24,118 --> 00:06:27,252
Makes sense, so this just keeps on
prompting, keeps on saying that stuff.

115
00:06:27,252 --> 00:06:31,724
And then at the very end we need to
let them know when they sell out, so

116
00:06:31,724 --> 00:06:34,475
let's just scroll all the way down here.

117
00:06:34,475 --> 00:06:36,788
Look at this, we're at 38 lines right now.

118
00:06:36,788 --> 00:06:40,879
So, we are going to,
here we are gonna notify

119
00:06:40,879 --> 00:06:46,230
the user that the tickets are sold out,
of course.

120
00:06:46,230 --> 00:06:51,096
After they are sold out,
after the continuum has happened.

121
00:06:51,096 --> 00:06:54,960
So one thing before I let you go,
I wanna show you this cuz it seems fair.

122
00:06:54,960 --> 00:06:59,893
If you highlight this you can go ahead and
you can do an Edit, and you can Indent.

123
00:06:59,893 --> 00:07:03,690
And you'll see here on my Mac,
it's command and then right bracket.

124
00:07:03,690 --> 00:07:07,470
So if you highlight some code,
you can do a command bracket or left

125
00:07:07,470 --> 00:07:11,640
bracket to go in and out to indent, that
helps when you wanna move a block over.

126
00:07:13,530 --> 00:07:15,662
So you've got this, right?

127
00:07:15,662 --> 00:07:19,970
You wanna run this code while
there are still some tickets left.

128
00:07:19,970 --> 00:07:21,480
And then at the very bottom,

129
00:07:21,480 --> 00:07:25,280
you want to print Sold Out when there
aren't tickets available anymore.

130
00:07:25,280 --> 00:07:26,018
You got this.

131
00:07:26,018 --> 00:07:26,799
Ready?

132
00:07:26,799 --> 00:07:27,889
Pause me.

133
00:07:29,610 --> 00:07:32,310
Okay, so, here's how I did it.

134
00:07:32,310 --> 00:07:35,341
So while there are tickets remaining.

135
00:07:38,155 --> 00:07:40,860
And then I went all the way
down to the bottom.

136
00:07:40,860 --> 00:07:44,461
I held down a Shift and
went all the way down to the bottom here.

137
00:07:46,729 --> 00:07:51,328
And then I went ahead and indented that.

138
00:07:51,328 --> 00:07:56,823
And down here we're just
gonna say print("Sorry

139
00:07:56,823 --> 00:08:00,537
the tickets are all sold out!!!

140
00:08:00,537 --> 00:08:04,810
I'm gonna make an emoji sad face,
because that seems aprops.

141
00:08:04,810 --> 00:08:07,870
Now, note, I used the truthiness
of tickets remaining.

142
00:08:08,960 --> 00:08:11,640
When this gets down to zero,
it will be false.

143
00:08:11,640 --> 00:08:14,860
Remember, any number
other thanzero is true.

144
00:08:14,860 --> 00:08:18,060
You know what though,
since I just had to explain that to you,

145
00:08:18,060 --> 00:08:20,510
maybe I should be more explicit.

146
00:08:20,510 --> 00:08:24,980
So let's do that, tickets remaining
are greater than or equal to one,

147
00:08:26,320 --> 00:08:30,760
we will run this code and then we will
notify them when they're sold out.

148
00:08:32,280 --> 00:08:34,880
Okay, let's see how we did.

149
00:08:37,820 --> 00:08:39,630
We'll say python masterticket.

150
00:08:40,980 --> 00:08:41,650
What is your name?

151
00:08:41,650 --> 00:08:45,410
My name is John and
I would like to have 98 tickets please.

152
00:08:45,410 --> 00:08:48,480
Total due is 980,
that seems reasonable, let's do it.

153
00:08:49,650 --> 00:08:51,210
There's 2 tickets left.

154
00:08:51,210 --> 00:08:52,460
So now Terry comes in.

155
00:08:53,500 --> 00:08:54,890
He buys 2.

156
00:08:54,890 --> 00:08:57,300
Total due is 20, Terry wants it.

157
00:08:58,520 --> 00:09:00,920
Sold, and
now the tickets are all sold out.

158
00:09:00,920 --> 00:09:02,000
Boom.

159
00:09:02,000 --> 00:09:03,390
Nice job.

160
00:09:03,390 --> 00:09:05,280
No more offering of tickets.

161
00:09:05,280 --> 00:09:06,460
All right, so let's move this over.

162
00:09:06,460 --> 00:09:08,110
This is done-zo.

163
00:09:08,110 --> 00:09:09,190
Feels so good doesn't it?

164
00:09:09,190 --> 00:09:10,630
Making something done.

165
00:09:10,630 --> 00:09:12,180
So, how'd you do?

166
00:09:12,180 --> 00:09:15,125
If you had any problems,
remember to ask in the community,

167
00:09:15,125 --> 00:09:18,270
if anything at all isn't clear,
we'll get it sorted out.

168
00:09:18,270 --> 00:09:22,570
Okay, we'll tackle those
user friendly errors next.

169
00:09:22,570 --> 00:09:24,539
It's our last ticket,
I'm gonna move it to In Progress.