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In Django, we control access to our views with URL patterns.
If you feel rusty or unsure about regular expressions, check out the course I did over them.
url() is a function that constructs a special object that Django uses to join URLs to view functions.
Some frameworks create
implicit URL mappings.
0:00
You make a function in a certain file,
you can get to that function through a URL
0:03
that's usually made up of the file
name followed by the function name.
0:06
Some frameworks let you assign a route or
0:09
URL to a view when you
create the function.
0:11
Django doesn't do either
of these things though.
0:14
Django's URLs are created
with regular expressions and
0:17
have a lot of hidden power in them.
0:19
We'll cover some of that
power in this course.
0:21
For now though, let's just get a single,
simple URL created.
0:23
If you got really nervous when I said
regular expressions, don't worry.
0:26
Our first one's going to be super
simple,and I'll link to my course on
0:29
Python regular expressions
in the teacher's notes.
0:32
You probably guessed this by now, but
the place to go add URLs is the in
0:35
the urls.py file in our
learning_site stub.
0:40
So let's open it up and take a look at it.
0:45
Right now it has some comments at the top,
and some imports.
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And then there is this urlpatterns thing.
0:52
Okay, so the first thing we need
to do is let's import our views.
0:58
We're gonna say from .,
which means the current directory.
1:02
Import views, and it's funny,
1:05
our editor always highlights this
as red like it's bad or something.
1:08
It's perfectly valid so,
just a little strange.
1:14
Okay, so we can see that we
have this urlpatterns, and
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there's already this thing in here.
1:22
That's called a URL.
1:25
So we're gonna add a new one, all right?
1:26
And we'll put it at the bottom,
cuz it's like our last thing.
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If everything else fails,
go to this one, right?
1:32
It's not guaranteeing that this is gonna
go to this one, but just, that's the idea.
1:34
Okay, so we're gonna mark it as
a raw string, cuz it's a regex.
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And if we do ^$,
that makes it an empty string,
1:43
cuz that's what we want.
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And then we're gonna do views.hello_world,
1:52
because hello_world is what
we named our view, right?
1:55
We come over here and look,
hello_world, hello_world.
1:58
So, we've imported our views.
2:03
We do that so that we have access to
our view functions that we've written.
2:05
And now we've added a new URL.
2:10
So now the URL objects, this thing here,
actually takes five different arguments.
2:13
The first argument's the pattern,
which we've given it, and
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that's a regular expression.
2:22
In this case we're
matching an empty string.
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Starts and
ends without any characters in the middle.
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Any request that comes
in to just your site,
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with no extra path,
is gonna match this pattern.
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It's gonna go straight there.
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Second part is the view to
send the request to, or
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the function, rather,
to send the request to.
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We want to go to the hello_world view,
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the hello_world function that
we created in the last video.
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And we don't wanna use
any parentheses here.
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We're not calling the view,
we just want to go to it,
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we wanna know which one it is.
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And the remaining parts that we're
not using are keyword arguments for
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the view, a name for the route, which
we'll get to that later, and a prefix.
2:57
We don't need to talk about most of those,
3:01
we're only gonna talk
about the name later.
3:04
Okay, so now we have a URL,
we have a view.
3:06
Let's check out our homepage.
3:11
There's our Hello World.
3:13
See, that wasn't so bad, was it?
3:16
Django URLs are a great way to get more
comfortable with regular expressions.
3:18
And like I said,
3:21
there's a whole other course you can take
that's just about regular expressions.
3:22
Okay, I think we're ready
to create our first app.
3:26
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