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Okay, first thing's first, I'm gonna wipe
our all these instructional columns.
0:00
Let's get rid of all of these,
clean that up a bit.
0:05
Let's get a little noisy.
0:08
All right, awesome.
0:11
So, that feels better.
0:13
Let's look at what we have left.
0:15
All right so we left done here because
we want to print the list out in
0:18
totality when it's done.
0:21
We wanna show the list and
there's this one here too.
0:22
I wanna see the list any time so
I can verify my order.
0:25
So let's make a new command for that.
0:28
That sounds good, all right?
0:31
So let's come back over here.
0:32
So first,
I'm gonna clean this up a little bit.
0:33
I'm gonna move this add to list
down below the show help and
0:36
typically what happens
in between functions,
0:41
you'll see that the starts getting
busy is you leave two spaces.
0:44
So there we, so we left that two
spaces between the two there.
0:48
Before and after, there you go.
0:52
All right, so we want to define a new
function that's named show list.
0:55
So let's do that.
1:03
So we'll say, define a function
1:03
named show_list that prints
1:10
all the items in the list.
1:15
That sounds good, right?
1:21
You got this, right?
1:23
You can loop through all of them and
print them out, right?
1:24
You got this, ready?
1:27
Pause me.
How did it go?
1:28
Here's how I did it.
1:31
So I said def show list.
1:32
Here's your list,
nice little heading there for it.
1:40
And we're gonna loop through that list.
1:45
So for each of the items In the shopping
list, we are going to print said item.
1:48
Awesome, and now,
we want to be able to have this called.
1:56
So let's make the command SHOW,
in all upper case.
2:04
So let's put it right here.
2:08
We'll say Enable the SHOW command,
2:09
cuz we wanna call that function
SHOW command to show the list.
2:16
Don't forget to update
the help documentation.
2:22
This is super important.
2:26
Sometimes you'll add a new command and
2:27
you'll forget that you've
already made this help.
2:29
And we have the help at the top of
the file, so don't forget to do that and
2:31
I wanna drop a hint here for you.
2:35
Make sure to run it.
2:38
Make sure that you run this
after you had that show command.
2:41
There's a little gotcha
if you forget something.
2:44
So make sure you run it, and
just make sure your list looks right.
2:46
Are you ready?
2:50
Pause me.
2:50
Did you catch it?
2:52
Here's what I did.
2:53
So I went ahead and it's another else if.
2:54
And if this is equal to our command
of show, we call the function.
2:57
But we got to remember to
use our control flow, right?
3:05
We gotta call continue and
3:09
if not, what will happen is show
will end up in your grocery list.
3:11
When you embrace flow control
like break and continue,
3:16
it's super important that you pay
attention to all the used cases.
3:18
All right, we are so close to done.
3:21
Now, we need to show
the list on completion.
3:24
So what we can do is when this while
loop is over while this while true when
3:27
this is over.
3:32
We can just call it.
3:34
We will call show_list.
3:38
Awesome let's give that a run.
3:43
Let's say, Python shopping list.
3:45
Look what I forgot to do.
3:55
I didn't update the help,
so I don't know about show.
3:57
I'm gonna do that.
3:59
Let me get back up in there.
4:00
Let's go back up in here.
4:01
So we'll add enter SHOW
4:04
to see your current list.
4:11
Awesome, whew that was close.
4:15
Okay so
we're gonna run Python shopping_list.py.
4:18
There's the show which
we pick up at the store.
4:24
Well obviously we need some tortillas.
4:29
Let's get some green chiles.
4:33
I need pork shoulder.
4:38
What am I forgetting?
4:41
What's on my list again?
4:42
What do I have here?
4:44
Right, tortillas, green chiles,
pork shoulders, cilantro.
4:46
There we go and now I am DONE.
4:52
And check it out there is my final list,
4:54
you're totally invited to my taco fiesta,
look at this.
4:57
We are all done, awesome.
5:01
Should we walk it one more time?
5:06
Let's do that.
So I'm gonna come in here.
5:09
I'm gonna get rid of these instructional
commands that we have in here.
5:10
Let's just walk it.
5:16
So we create our brand new list that
the program will use in a global fashion.
5:18
And then our program is gonna
accept multiple commands.
5:24
So we should have some detailed help,
right?
5:28
Programs are no good if
users can't use them.
5:30
So we print out our help, and
then we have our add to list function.
5:32
And it appends a value to
the end of our shopping list and
5:38
updates the user with the count.
5:41
And lists and most objects for
5:45
that matter can make use of
the len command, so pythonic.
5:46
And then we have our show list,
and lists are iterable,
5:52
so we can loop through them
with a for item in list.
5:57
Now, this is kind of strange, right?
6:01
So we have this while True.
6:05
One way to write loop that take
many flows is to set things up
6:07
in an infinite loop matter.
6:10
While true is always gonna happen,
6:12
we rely on further control flow
to control how things happen.
6:14
We take a single prompt and
since it can be an item or
6:20
a command,
we have made the prompt generic.
6:24
A little greater than sign,
feels kinda good.
6:27
And then we just check
each of our commands.
6:30
So here's the flow if the user is done.
6:33
Break out of the while loop,
we are done with this while loop,
6:38
we don't anything more to do so
break out of it.
6:41
Otherwise if we're looking for help,
show it and remember to control the flow.
6:44
Calling continue will shoot us back up to
this while true line which is no surprise,
6:51
still true.
6:56
What this avoids is us from continuing and
adding help to our grocery list.
6:58
We don't want that.
7:02
Well, at least not from the grocery store.
7:03
Now, I of course, could have just put this
add to list inside of an else and we could
7:05
remove the continues, but then I would've
been able to show you the continue loop.
7:10
So I want you to be cautious of
controlling the flow with break and
7:14
continue.
7:18
Break is known to break your program,
7:19
and then finally we add that
new item to our function.
7:21
It comes into the add to list then boom,
here we go.
7:26
So I hope that that all made sense, and
7:29
if there is anything at all that is still
confusing you, feel free, rewind it,
7:32
watch it again and hit the forum if
there's anything confusing at all.
7:36
You did an awesome job,
enjoy the taco party.
7:40
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