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- [Tim] All right so moving on now.

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So we're at the stage
now where we're going

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to start populating the songs list

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when we actually click on an album.

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So it's really just more of the same.

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Now we don't really want
to do what I'm about to do.

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The long-winded way is to
create another function,

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get underscore songs, let's say

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and bind that to the album's ListBox.

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And the approach we'll
take in the next video

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is to subclass our ScrollBox class

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and get the ListBoxes
to populate themselves.

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Sometimes you have to
start duplicating code

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before you spot that there is duplication.

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So I'm going to get
this songs list working

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so we can see what the common code is

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and how we can ultimately avoid that.

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Now get_songs is going to be
very similar to get_albums,

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I'm going to add it just
below the get_albums function.

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And leaving two blank lines is normal

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between functions there or methods.

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Def get_songs(event):

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lb = event.widget

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now we want to do an index

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index = int(lb)

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Let's close down the update
or do that update a bit later.

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(lb.curselection()

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then we want square bracket zero

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and a right parentheses

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album_name = lb.getindex

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or get parentheses index I should say,

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then that all-important comma on the end.

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And then we're going to get the artist ID

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from the database row.

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So # get the artist ID
from the database row

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and when we do that by typing

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album_id = conn.execute

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parentheses and then double quotes,

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SELECT albums._id

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FROM albums

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where albums.name

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is equal to question
mark, end of double quote

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comma, space, album_name,

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finish the parentheses
and then dot fetchone()

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and make a call to that method.

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And alist = []

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and we want to select the
song, so we're going to do

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for x in conn.execute

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and the SQL line of code in double quotes

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SELECT songs.title

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FROM songs WHERE

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songs.album=?

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And ORDER BY songs.track"",

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double-quote, comma, space

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and album_id):

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and alist.append

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(x)[0])

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then end the parentheses,

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then the last line of code

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songLV.set

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I've seen this in the get_albums method

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(tuple(alist))

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So really apart from the
column and table names

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this code is pretty much identical

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to the get_albums function.

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So we just have to bind the function now

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to the album ListBox selected event

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and the songs list will
hopefully be updated

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when we click on a new album.

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So we'll go to our albums ListBox

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and after the config border=2 line

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we're going to type

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albumList.bind

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('<<

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single quotes, less than, less than

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and it's going to be

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ListboxSelect>>',

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again greater than sign,
greater than sign, single quote,

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get_songs)

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to call that method.

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Again there's no parentheses there

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after the get_songs.

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So now if we run this,

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we should see that the songs will update

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when we select an album.

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So let's just click on AC DC

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For Those About to Rock

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And you can now see the
songs are now showing up here

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on the right-hand side.

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So excellent.

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We got that to work.

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But there is a bit of
a problem here still,

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so we select another album,

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like for example Axel Rudi Pell

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select one of the albums to show.

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That's fine but if we now
select a different artist,

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the songs from the Axel Rudi Pell album

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are still being displayed.

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So come over here

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they haven't been reset in other words,

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until we actually select a different album

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for that particular artist.

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So really we need to reset the songs list

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whenever the artist changes.

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So let's go ahead and do that.

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And that's pretty easy to do.

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And it's done down here,
or up here I should say,

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In the get_albums method.

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So we initialise it in there, so we put

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songLV.set(("Choose an album",))

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so let's try running that again.

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So we'll do the same thing now.

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We'll just choose Axel Rudi Pell

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choose an album

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that works okay.

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And if we go back to say to AC DC,

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we can see the songs is correctly updated,

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or the message, default
message, is now showing

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in the songs list

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and the previous selection,
or list of songs,

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has been cleared.

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So basically the song list now is cleared

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whenever a new artist is selected

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and that's actually quite important

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because it does have a slight
impact on our subclass.

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But we'll see about
that in the next video.