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- [Narrator] Hi, and
welcome back to the course.

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Remember our simple Flask application?

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Now, we're going to extend
that to show the endpoints

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that we looked at in the
very last presentation.

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We're going to simulate an
online store using Flask.

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There were a couple of
things that we discussed.

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Net post was used to receive data,

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and the get was used to,
essentially, send data back only.

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Remember, from the browser's perspective,

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this is the opposite.

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The browser will use post to send us data.

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And it will use get to receive data.

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But here, we are not a
browser, we are a server.

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So, when we receive a post request,

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that means we are receiving some data,

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and therefore we have to deal with it.

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And when we receive a get request,

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that means that we have to send data back.

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For example, when we receive post store,

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and that means that we have
to probably create a store.

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We may receive get store, and that means

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we have to send back a list of stores.

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So, the endpoints that we're gonna create

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are post for store, and this is,

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the data that we're
gonna receive is a name.

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We're gonna create get of store,

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slash string name.

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Get for stores, we're gonna create post

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for a store string, oh, apologies,

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string name item.

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And also get for store string name item.

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So, what these endpoints are gonna do

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is, the first one is
gonna create a new store

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with a given name.

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The second one is going to
get a store for a given name,

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and it's gonna return some data about it.

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The third one is going to
return a list of all the stores.

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The fourth one is going to create an item

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inside a specific store,
with a given name.

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And the last one is
gonna get all the items

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in a specific store.

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This one will also have a
name and a price, for example.

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OK.

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So, I'll create an
example of a post request

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and a get request for you,

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and then we, I'll expect
you to create the rest.

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So, for the first port request.

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Well, we know how to create an endpoint.

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It is @app.root, and here,
before we put a forward slash,

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that was the root of our
application, the home page,

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now we wanna put it as slash store,

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because that is what this endpoint is.

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Therefore, our browser,
or our web application,

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or our m, whoever is
really calling our API

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is going to call this endpoint.

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However, it has to be a post.

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By default, when you use app.route,

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that is a get request.

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And browsers, by default,
only do get requests.

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So, we're gonna need to say
comma methods equal post.

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So, this defines our route
as being slash store,

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and as being accessible
only via a post request.

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If we want it to be accessible
via a get request, as well,

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then we could do post and get.

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So then, this endpoint could be called

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either via post or via get.

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We will look at how that
works later on in the course.

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Then, we have to associate
a method with it.

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And in this case, I'm gonna
call the method create store.

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And it's not going to do anything for now,

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but we will make it do stuff later on.

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To get the store, well, fairy simple.

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I'm sure you can do it yourself.

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So, if you think you
can, pause the video now

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and give it a go.

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And if not, just keep watching
and I will implement it here.

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To get a store, we'll have
app.route slash store,

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slash string name.

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This is a special Flask bit of syntax,

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which means that when we get store,

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when we create our method,

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our method can have a
parameter, which is name.

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This name here has to match this one here.

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And therefore, when we receive a request

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such as an
http://107.0.0.1/5000/store/some_name,

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some name is going to be this name here.

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So, the name variable
will contain some name.

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If we have a store that has that name,

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we're gonna be able to return
it, using that as a key.

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OK.

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So, this is also going to pass.

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And then, you know, this
is just going to apply

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for, really, the rest of them.

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And this one is only store, so it doesn't

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need the string name.

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And also, it's not gonna have a parameter.

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For the post, we're going
to copy this one here,

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and it's gonna have
string name slash item.

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Make sure to not forget
any of these little bit

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of syntax there, because
that can be quite confusing

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for Flask if you do that.

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And finally, we're going to
have something like this,

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down here.

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Remember to change the
method names, as well,

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because they have to be unique.

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So, I'm gonna call this
method get item store,

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because that's essentially
what this is going to do.

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This is going to retrieve all the items

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in a specific store.

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For this one, it's going
to be create item in store.

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For this one, it is gonna get stores,

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and this one is gonna be get store.

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This one is gonna be create store.

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So, these are our endpoints.

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So, we've got our five endpoints now,

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as we discussed in the last presentation.

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And all we have to do now
is really implement them.

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So, how do we implement them?

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Well, we, first of all, need
a way to store our stores.

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So, that can be, for example,
something like a list.

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And our stores can be
an empty list initially,

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and then it can have a dictionary in it,

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and the dictionary is gonna have a name,

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and the name's gonna be, for example,

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My Wonderful Store.

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And there's also gonna
have a list of items,

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and each item is going to have a name,

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such as My Item and a
price, such as 15.99.

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OK.

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So, hopefully this makes sense.

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I'm just gonna clean
this up a bit for you,

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so it's a bit easier to
understand or to know.

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OK.

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So, our store's list is
going to contain a list

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of dictionaries.

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So, here we've got one dictionary,
but we could have many.

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Each dictionary has a name,
such as our stores do,

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and the name, in this case,
is My Wonderful Store.

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And it also has a list of items.

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And in this case, items is a list.

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So, we can have many other
dictionaries in here,

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and each dictionary is
going to have a name

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and a price.

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We could do this with
object oriented programming,

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if we wanted, and we're gonna explore

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how to do that later on, of course.

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And also, normally, we would
be storing these things

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to a database, but in
order to simplify things

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and just teach you the basics of RS API,

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we're gonna stick to having
a dictionary here, in memory.

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So, hopefully that's all right.

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And in the next video, we're going to look

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into implementing these endpoints.

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So, I'll see you there.