1
00:00:00,550 --> 00:00:02,351
Our app is looking great, but

2
00:00:02,351 --> 00:00:08,010
I think we can add a few more features to
make this even more useful for our users.

3
00:00:08,010 --> 00:00:11,211
What happens if they make
a mistake when entering a book or

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00:00:11,211 --> 00:00:13,440
what if the price changes?

5
00:00:13,440 --> 00:00:16,750
Right now you can't do anything about it.

6
00:00:16,750 --> 00:00:20,270
Also, what if you want to remove a book?

7
00:00:20,270 --> 00:00:23,260
Let's introduce these
two features to our app.

8
00:00:23,260 --> 00:00:26,150
We can add them as a part
of our search feature.

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00:00:26,150 --> 00:00:30,296
When someone searches for a book,
we can give them the option to edit,

10
00:00:30,296 --> 00:00:33,250
delete or return to the main menu.

11
00:00:33,250 --> 00:00:37,370
Let's handle this like our other menu,
by giving it its own function.

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00:00:37,370 --> 00:00:39,698
To keep similar things together,

13
00:00:39,698 --> 00:00:43,321
let's create our sub menu
right below our main menu.

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00:00:45,100 --> 00:00:53,444
I can actually remove these, There we go,

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00:00:53,444 --> 00:01:00,440
submenu, and
we can actually copy this here.

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00:01:00,440 --> 00:01:05,785
And if you want, you could actually
make a single menu function and

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00:01:05,785 --> 00:01:11,905
then pass in values for the options and
the list of numbers and all that jazz.

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00:01:15,885 --> 00:01:20,529
All right, so we only have three options
and it's no longer programming books,

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00:01:20,529 --> 00:01:22,170
we can also get rid of that.

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00:01:22,170 --> 00:01:27,166
One will be edit, two will be delete,

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00:01:27,166 --> 00:01:32,170
and three will be return to main menu.

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00:01:33,960 --> 00:01:38,017
And then we can get rid of four and
five, so we only have three options, and

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00:01:38,017 --> 00:01:40,840
then we can get rid of five,
and switch it to three.

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00:01:42,150 --> 00:01:42,650
Wonderful.

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00:01:43,680 --> 00:01:47,020
Now we can create the structure for
each response in our app.

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00:01:47,020 --> 00:01:49,493
So let's jump down to app.pi.

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00:01:56,046 --> 00:01:57,620
Okay, so we have search for book.

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00:01:58,690 --> 00:02:04,040
And then instead of this input,
we're going to give them a submenu.

29
00:02:04,040 --> 00:02:08,660
So I'm gonna call it sub_choice = submenu.

30
00:02:10,120 --> 00:02:14,470
And then, if sub_choice

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00:02:14,470 --> 00:02:19,609
== '1' this will be edit,

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00:02:19,609 --> 00:02:23,790
pass for right now.

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00:02:23,790 --> 00:02:28,980
And then, elif, sub_ choice = '2'.

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00:02:30,200 --> 00:02:32,490
This will be delete.

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00:02:32,490 --> 00:02:34,690
And I'll still put pass for right now.

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00:02:34,690 --> 00:02:38,366
And then we actually don't need to do
one for three because of our loop,

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00:02:38,366 --> 00:02:40,770
it'll automatically jump
it back to the top.

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00:02:42,330 --> 00:02:44,360
Now it's time to tackle edit.

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00:02:45,490 --> 00:02:48,852
Let's think about what we need
to happen here a bit first.

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00:02:48,852 --> 00:02:53,751
We'll need to print out the current value
for each book's title, date, etc., so

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00:02:53,751 --> 00:02:56,379
the user can see what
the value currently is.

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00:02:56,379 --> 00:02:59,630
Then we'll need to ask them
to update the information.

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00:03:00,670 --> 00:03:05,198
And we'll need to repeat this for
each column, the title, author,

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00:03:05,198 --> 00:03:07,080
price, date, all of them.

45
00:03:08,490 --> 00:03:10,921
And the keyword here is repeat.

46
00:03:10,921 --> 00:03:15,440
We're going to need to do this task for
each value.

47
00:03:15,440 --> 00:03:19,096
So that means we're going to need
a function to handle this task so

48
00:03:19,096 --> 00:03:21,100
that we can call it for each column.

49
00:03:22,380 --> 00:03:26,723
I'm going to place this new function
after our cleaning functions and

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00:03:26,723 --> 00:03:28,352
before the CSV function.

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00:03:31,680 --> 00:03:32,396
Right here.

52
00:03:37,315 --> 00:03:41,897
I'm gonna call it edit_check, and inside,

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00:03:41,897 --> 00:03:46,150
we're going to get the column_name.

54
00:03:46,150 --> 00:03:48,617
This is because for
the price and for the date,

55
00:03:48,617 --> 00:03:52,800
we're gonna need to do something different
compared to the author and title.

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00:03:54,000 --> 00:03:57,620
And then we want the current_value.

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00:03:59,930 --> 00:04:01,140
Okay.

58
00:04:01,140 --> 00:04:04,765
And inside of our edit_check function,
let's print out the column names so

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00:04:04,765 --> 00:04:07,010
they know which column
they're dealing with.

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00:04:08,280 --> 00:04:13,103
I make this an F string and
I start it on a new line,

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00:04:13,103 --> 00:04:17,811
and I give a couple stars,
I'm gonna do EDIT and

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00:04:17,811 --> 00:04:24,910
then column_name, And
a few stars, close it out.

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00:04:24,910 --> 00:04:26,340
Cool.

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00:04:26,340 --> 00:04:29,620
Now we need to show the current value for
each column.

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00:04:29,620 --> 00:04:32,369
But remember if it's the price or
the published date,

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00:04:32,369 --> 00:04:36,710
we're going to need to show it how we
want to receive the information too.

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00:04:36,710 --> 00:04:42,240
So for instance,
let's do if column_name == 'Price'.

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00:04:43,560 --> 00:04:49,512
We're going to print,
An f string of the current value.

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00:04:52,611 --> 00:04:59,981
Current Value, and
we're going to need the current_value and

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00:04:59,981 --> 00:05:03,810
it needs to be divided by 100.

71
00:05:03,810 --> 00:05:08,906
So it's now back into that 1099
price instead of the price in cents,

72
00:05:08,906 --> 00:05:12,090
cuz that's how we want
to receive the price.

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00:05:12,090 --> 00:05:14,036
So if we model it here for the user,

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00:05:14,036 --> 00:05:17,740
then it kinda shows what we want
the information to come in as too.

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00:05:18,810 --> 00:05:22,114
So let's do the same thing for the date.

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00:05:28,799 --> 00:05:36,190
Okay, so if the column_name == 'Date',
we still want to print an f string,

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00:05:36,190 --> 00:05:40,990
and this is going to say same thing,
Current Value.

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00:05:42,320 --> 00:05:46,467
And to translate the date
into the format we want,

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00:05:46,467 --> 00:05:52,318
we're going to need to use
current_value.strftime to convert it.

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00:05:52,318 --> 00:05:52,948
And oops,

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00:05:52,948 --> 00:05:57,770
we need to make sure to use double quotes
because we're inside of single quotes.

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00:05:57,770 --> 00:06:00,160
So we want to make sure we
use double quotes here.

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00:06:00,160 --> 00:06:06,046
And to get the month converted to
the name of the month, we want %B,

84
00:06:06,046 --> 00:06:11,931
and then, we need the day, that's %d,
and then we need the year,

85
00:06:11,931 --> 00:06:18,220
that's %Y to get the full year, Okay?

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00:06:18,220 --> 00:06:20,590
And then, we need an else.

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00:06:20,590 --> 00:06:24,388
So if it's any of the other columns,
we're just going to print the value.

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00:06:26,190 --> 00:06:32,334
String, do a return, Current Value.

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00:06:32,334 --> 00:06:34,364
And that's just going to be current_value.

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00:06:36,415 --> 00:06:37,880
Great.

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00:06:37,880 --> 00:06:39,040
Okay.

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00:06:39,040 --> 00:06:43,434
Now we're also going to need to do
something a little special if it's

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00:06:43,434 --> 00:06:48,661
the published date or the price because we
need to use our clean date and clean price

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00:06:48,661 --> 00:06:54,690
functions again, so that we can turn their
string input into the correct format.

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00:06:54,690 --> 00:06:58,635
So, I'm gonna just to help break
it up a little bit, I'm gonna add

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00:06:58,635 --> 00:07:02,868
a space here to help differentiate
between these kind of two sections.

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00:07:02,868 --> 00:07:06,315
So we printed out the information so
they can see it and now we're gonna

98
00:07:06,315 --> 00:07:09,830
get into actually asking them for
their input and interacting with it.

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00:07:10,930 --> 00:07:14,622
So if column_name == 'Date' or

100
00:07:14,622 --> 00:07:18,561
if the column_name == 'Price',

101
00:07:18,561 --> 00:07:23,745
then we're going to want
to do some stuff in here.

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00:07:23,745 --> 00:07:27,167
And it's going to be inside of a while
loop because we have to work with

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00:07:27,167 --> 00:07:30,059
the clean date functions and
we need to keep asking them for

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00:07:30,059 --> 00:07:33,770
information until they give it
to us in the correct format.

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00:07:33,770 --> 00:07:36,270
I'm just gonna put pass inside for
right now.

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00:07:36,270 --> 00:07:41,416
Okay, and then on the outside, we're gonna
need an else, and we can just return

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00:07:41,416 --> 00:07:47,560
if it's not one of these two columns, that
means it's either the author or the title.

108
00:07:47,560 --> 00:07:49,513
And so we can just ask for the input and

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00:07:49,513 --> 00:07:52,830
we can just return their
response right away.

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00:07:52,830 --> 00:07:55,820
Because it's in a string format and
that's all it needs to be.

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00:07:58,040 --> 00:08:05,281
So 'What would you like
to change the value?

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00:08:05,281 --> 00:08:09,670
' Okay, so
now let's handle inside of our while loop.

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00:08:11,770 --> 00:08:13,190
We need to ask the same question.

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00:08:13,190 --> 00:08:14,660
So I'm gonna call it changes.

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00:08:15,820 --> 00:08:19,108
And I'm actually just gonna
use the exact same question.

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00:08:22,090 --> 00:08:23,060
There we go.

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00:08:23,060 --> 00:08:23,830
Okay.

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00:08:23,830 --> 00:08:27,600
And then we need to call clean date for
the date and clean price for the price.

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00:08:27,600 --> 00:08:31,380
And now we want to break it up then
into either the date or the price.

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00:08:31,380 --> 00:08:35,870
So column_name == 'Date'.

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00:08:35,870 --> 00:08:40,660
Then we're going to do something
very similar to what we did before.

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00:08:40,660 --> 00:08:45,727
And say the changes are now equal

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00:08:45,727 --> 00:08:50,987
to the clean version of changes.

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00:08:50,987 --> 00:08:57,278
And if the type(changes) == datetime.date,

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00:08:57,278 --> 00:09:00,788
then we can return changes,

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00:09:00,788 --> 00:09:07,650
cuz remember return
automatically stops a loop.

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00:09:07,650 --> 00:09:11,257
And that's why we're using while
true instead of using a variable to

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control our loop.

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00:09:13,380 --> 00:09:16,731
Okay, so that takes care of the date and

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00:09:16,731 --> 00:09:21,922
we're gonna do essentially
the exact same thing for price.

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00:09:21,922 --> 00:09:27,378
== 'Price' to changes

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00:09:27,378 --> 00:09:31,349
= clean_price.

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00:09:31,349 --> 00:09:33,691
And we're gonna pass in changes.

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00:09:33,691 --> 00:09:38,716
And then if type(changes) is

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00:09:38,716 --> 00:09:45,680
an integer then we can return our changes.

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00:09:47,350 --> 00:09:48,080
And let's save.

137
00:09:49,930 --> 00:09:50,430
Awesome.

138
00:09:52,660 --> 00:09:57,259
Now let's pop down into the app.pi and
call our new function.

139
00:10:00,475 --> 00:10:02,560
Here we are in edit.

140
00:10:02,560 --> 00:10:05,409
Now remember when we're updating a value,

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00:10:05,409 --> 00:10:09,190
we need to set the current
value equal to something else.

142
00:10:09,190 --> 00:10:11,840
And we've already grabbed
our book previously.

143
00:10:11,840 --> 00:10:15,290
We have it here in
a variable called the_book.

144
00:10:15,290 --> 00:10:19,861
So we just need to set
the_book.title equal to and

145
00:10:19,861 --> 00:10:27,100
then we'll call our edit_check('Title')
to pass in the column name.

146
00:10:27,100 --> 00:10:31,054
And then we can actually just copy
this because it's the same thing,

147
00:10:31,054 --> 00:10:34,640
the_book.title to pass
in the current value.

148
00:10:34,640 --> 00:10:36,850
And we'll do that for each column.

149
00:10:36,850 --> 00:10:42,280
So the_book.author, and
I'm gonna copy that.

150
00:10:42,280 --> 00:10:48,745
Goes edit_check('Author'),
and then the_book.author.

151
00:10:48,745 --> 00:10:52,147
And the next one the_book,

152
00:10:52,147 --> 00:10:56,968
and then we'll do .published_date,

153
00:10:56,968 --> 00:11:02,214
copy that, = edit_check('Date'),

154
00:11:02,214 --> 00:11:08,043
and then fill in the_book.published_date.

155
00:11:08,043 --> 00:11:11,055
And lastly the_book.price,

156
00:11:13,345 --> 00:11:18,340
Copy that, and =edit_check('Price').

157
00:11:19,810 --> 00:11:22,158
And then the_book.price.

158
00:11:22,158 --> 00:11:27,957
And then below here let's
do a print(session.dirty)

159
00:11:27,957 --> 00:11:35,460
to see if the changes are being grabbed
by our session, just to make sure.

160
00:11:36,500 --> 00:11:39,010
So let's make sure we saved.

161
00:11:39,010 --> 00:11:43,340
And I'm gonna pull this up so
you can see more of our console.

162
00:11:43,340 --> 00:11:44,449
And let's run the file.

163
00:11:46,674 --> 00:11:50,004
Oops, I have an IndentationError, line 29.

164
00:11:50,004 --> 00:11:50,770
Let's go check it out.

165
00:11:52,960 --> 00:11:56,393
Popping up to line 29.

166
00:11:59,632 --> 00:12:00,340
Yes.

167
00:12:01,426 --> 00:12:06,560
Somehow we got menu inside of, oops,
I don't know how that happened.

168
00:12:06,560 --> 00:12:07,610
We don't need that.

169
00:12:07,610 --> 00:12:08,110
There we go.

170
00:12:09,200 --> 00:12:10,527
That should be much better.

171
00:12:16,700 --> 00:12:17,470
There we go.

172
00:12:17,470 --> 00:12:18,510
Okay.

173
00:12:18,510 --> 00:12:20,300
So let's search for a book.

174
00:12:20,300 --> 00:12:23,110
Let's do book 11 cuz we
know that's my silly one.

175
00:12:24,970 --> 00:12:27,041
Jethro's Favorites, let's edit it.

176
00:12:27,041 --> 00:12:28,260
So I'm gonna do one.

177
00:12:29,440 --> 00:12:31,460
Okay, so
the current value is Jethro's Favorites.

178
00:12:31,460 --> 00:12:33,339
What would you like to
change the value to?

179
00:12:33,339 --> 00:12:36,340
And here in my console,
I can copy and paste.

180
00:12:36,340 --> 00:12:39,570
I know in some consoles it
doesn't always let you.

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00:12:39,570 --> 00:12:40,589
I'm just gonna leave that.

182
00:12:40,589 --> 00:12:45,246
I'm gonna change this
value to Jethro Amendola.

183
00:12:45,246 --> 00:12:46,427
What do I want to change the date to?

184
00:12:46,427 --> 00:12:52,950
Let's change the date to, actually,
let's test this, 23rd 2003.

185
00:12:52,950 --> 00:12:54,210
It should give me an error.

186
00:12:54,210 --> 00:12:55,730
Cool, and that should ask me again.

187
00:12:57,370 --> 00:12:58,989
What would you like to
change the value to?

188
00:12:58,989 --> 00:13:00,000
Awesome.

189
00:13:00,000 --> 00:13:01,032
Now let's give it a real date.

190
00:13:01,032 --> 00:13:04,967
Let's do June 14, 2020.

191
00:13:06,802 --> 00:13:08,850
And now we're on Price, perfect.

192
00:13:08,850 --> 00:13:09,432
So it took it.

193
00:13:09,432 --> 00:13:11,010
Let's give it an incorrect price here.

194
00:13:11,010 --> 00:13:14,317
So let's do $4 but with the dollar symbol.

195
00:13:14,317 --> 00:13:17,160
And, yep, gave us that error.

196
00:13:17,160 --> 00:13:19,180
Let's press enter to try again.

197
00:13:19,180 --> 00:13:22,600
And let's just keep it at 5.99.

198
00:13:22,600 --> 00:13:23,930
Cool.

199
00:13:23,930 --> 00:13:26,486
And you can see we have
our identity set here,

200
00:13:26,486 --> 00:13:29,610
which means that it is
captured by session.

201
00:13:29,610 --> 00:13:32,656
And we have Jethro's Favorites,
we can see the change to the author,

202
00:13:32,656 --> 00:13:35,930
the change to the published date,
and the price is the same.

203
00:13:35,930 --> 00:13:36,590
Amazing job.

204
00:13:38,240 --> 00:13:40,720
So our changes are being added to session.

205
00:13:40,720 --> 00:13:45,620
But to make the changes reflected in the
database, let's make sure to commit them.

206
00:13:50,195 --> 00:13:53,140
And then let's print out a nice message so

207
00:13:53,140 --> 00:13:56,430
that the user knows that
our book was updated.

208
00:13:58,470 --> 00:14:05,719
And then let's do a time.sleep, 1.5.

209
00:14:05,719 --> 00:14:09,080
Save, and amazing,
our edit functions are working.

210
00:14:10,140 --> 00:14:11,760
Now let's get to delete.

211
00:14:13,030 --> 00:14:16,690
This one is 1,000 times easier, I promise.

212
00:14:16,690 --> 00:14:17,220
Are you ready?

213
00:14:18,300 --> 00:14:21,570
We already know we still
have access to the book.

214
00:14:21,570 --> 00:14:27,640
So we'll do a session.delete(the_book),

215
00:14:27,640 --> 00:14:30,601
session.commit, and

216
00:14:30,601 --> 00:14:35,485
then we can just copy our message here so

217
00:14:35,485 --> 00:14:42,749
they get the same message,
except this will say deleted.

218
00:14:44,552 --> 00:14:45,910
And that's it.

219
00:14:47,860 --> 00:14:49,467
That's the code.

220
00:14:49,467 --> 00:14:53,675
Let me save this to Python app.pi.

221
00:14:53,675 --> 00:14:58,870
Let's do 3 and 11,
since that's our silly book.

222
00:15:01,190 --> 00:15:07,210
And scroll up so
you can see that it's Jethro's Favorites.

223
00:15:07,210 --> 00:15:11,590
And let's do 2 for delete, book deleted.

224
00:15:11,590 --> 00:15:14,913
And then we can check by running,
view all books and

225
00:15:14,913 --> 00:15:18,170
we only have ten books in the database,
amazing.

226
00:15:19,210 --> 00:15:24,230
Pat yourself on the back, you've tackled
a ton of code so far in this course.

227
00:15:24,230 --> 00:15:27,214
Don't forget to take time to
review what you've written and

228
00:15:27,214 --> 00:15:31,460
maybe go line by line and try to
explain to yourself what's happening.

229
00:15:31,460 --> 00:15:34,874
This is a great way to get used
to thinking about how your code

230
00:15:34,874 --> 00:15:38,320
is working and
is a skill used in technical interviews.

231
00:15:38,320 --> 00:15:41,520
So use every opportunity to practice.

232
00:15:41,520 --> 00:15:45,252
Don't forget, run your Git commands,
add, commit and

233
00:15:45,252 --> 00:15:47,519
push your changes up to your repo,