Django Tutorial Walkthrough 1

I am learning Django (again) via the official Django tutorial. You may follow along if you are learning as well.

Transcript

The following transcript was automatically generated by an algorithm.

00:00 : hi there welcome to a code tutorial
00:03 : walkthrough for the django web
00:05 : application framework
00:07 : uh i'm going to jump right into it
00:10 : um
00:12 : to find the django project you can just
00:15 : go search for it in a search engine
00:19 : and uh the
00:20 : the website for the django project is
00:24 : djangoproject.com
00:26 : um
00:28 : so uh we to get started so let's go
00:30 : click on that
00:32 : um all right so depending on how new you
00:35 : are to django
00:37 : you can try a django tutorial or just
00:40 : dive into the documentation so
00:43 : i have used django before but i'm gonna
00:46 : go into it from a beginner's perspective
00:49 : so let's try a tutorial
00:55 : okay
00:57 : um
00:58 : we'll assume you have django installed
01:00 : already which i don't
01:02 : i don't
01:03 : so i'm gonna go through the installation
01:05 : as well so
01:07 : let's go
01:08 : click on this link and have it in a
01:10 : separate tab
01:12 : we're gonna go ahead and install django
01:15 : so
01:16 : first you need to install python i do
01:19 : have python installed
01:21 : but uh it
01:23 : and i will assume that you know the
01:25 : python programming language so i'm not
01:27 : going to cover that part of it
01:32 : you may want to set up a database um
01:35 : i'm going to skip that part that part is
01:38 : optional i'm gonna go straight through
01:41 : installing django so you have three
01:43 : options to install django
01:46 : you can install
01:48 : uh the official release this is the best
01:50 : approach for most users so i'm just
01:53 : gonna go for that
01:59 : okay
02:01 : so
02:03 : so this is the recommended way to
02:05 : install django looks like you just run
02:07 : this command you need to install pip
02:10 : but in the latest version of
02:12 : python i'm pretty sure pip
02:15 : comes out of the box with python
02:18 : so i will already have it
02:20 : if not then you can use the pip
02:23 : installer which is
02:25 : uh on inside of this link here i'm gonna
02:28 : open up my terminal
02:30 : i'm on a mac
02:33 : and uh
02:34 : i'm going to go ahead
02:37 : and
02:38 : type in this command
02:40 : to install jango
02:42 : i'm going to bump up the font size a
02:44 : little bit more actually
02:56 : okay let's do python dash m pip
03:00 : install
03:01 : jangle
03:06 : so
03:07 : it looks like the
03:08 : d is capitalized
03:11 : so that might be important i think
03:14 : package names are case sensitive
03:17 : so it's downloaded
03:19 : about eight megabytes worth
03:22 : of code
03:24 : and
03:25 : [Music]
03:27 : some of the dependencies were already
03:29 : satisfied that's fine
03:31 : okay
03:32 : so i think i have installed django uh
03:35 : these are the alternative methods for
03:38 : installing django but i did the main one
03:40 : so i'm gonna skip those
03:43 : and
03:45 : at the end i can verify that django has
03:48 : been
03:49 : installed correctly by running a python
03:52 : shell
03:54 : importing django
03:57 : lowercase d this time
03:59 : and then i can print the
04:03 : django.getversion to get the version
04:05 : number
04:07 : 4.0.2 which is slightly
04:10 : uh
04:11 : newer
04:13 : uh when the author of this tutorial put
04:16 : this
04:17 : tutorial together
04:19 : um so also
04:21 : i will make a note that
04:23 : the
04:24 : the tutorial that i am following today
04:28 : could
04:28 : go out of date at some point
04:32 : but
04:33 : as you can see i'm doing this based on
04:36 : django 4.0 and python version 3.9.2
04:42 : and the date here is february 1st
04:46 : uh 2022
04:51 : okay so i think
04:53 : i have done the installation and i can
04:56 : move on to the tutorial
05:00 : which was here
05:02 : all right i have two tabs
05:05 : two open tabs for the same page so i'll
05:07 : close one of them
05:09 : all right
05:13 : ah yeah that's what i just said
05:15 : um
05:15 : [Music]
05:17 : i guess
05:18 : um
05:19 : not now that i have i kind of did this
05:22 : backwards i think
05:24 : i think i want to do an overview first
05:28 : um
05:29 : explaining what django
05:31 : is
05:32 : so
05:33 : let's read this why django with django
05:35 : you can take web applications from
05:38 : concept to launch in a matter of hours
05:41 : so it allows you to develop
05:44 : dynamic
05:45 : web applications quickly
05:50 : um ridiculously fast i think that means
05:55 : to develop her time
05:57 : is quick
05:58 : not the performance is quick necessarily
06:01 : is fully loaded
06:03 : um
06:06 : secure okay
06:09 : scalable
06:10 : versatile etc
06:12 : okay those are the selling points of
06:14 : django
06:16 : um
06:17 : and it django is built on top of the
06:20 : python programming language and python
06:22 : programming language is one of the most
06:25 : developer friendly programming languages
06:28 : that i know
06:30 : and in my opinion the best programming
06:33 : language for teaching
06:38 : okay let's just jump into this
06:40 : let's create a new django project so
06:44 : if this is your first time using django
06:46 : you have to take care of some initial
06:48 : setup
06:50 : okay so i'm gonna do this
06:53 : there's going to be a django admin
06:55 : command that
06:57 : has been uh installed as the that
07:01 : as the process of installing django
07:03 : itself so i'm going to go ahead and do
07:05 : that i'm going to go into a directory
07:09 : called playground which is where i uh
07:12 : normally
07:15 : uh
07:16 : do any kind of
07:18 : play uh
07:19 : programming play projects
07:22 : uh of all sorts
07:24 : so they're saying uh we're gonna
07:27 : we're gonna type a command django admin
07:30 : start project my site
07:32 : and it's going to create a my site
07:35 : directory in my current directory
07:38 : i don't want to call it my site
07:41 : because i want to differentiate it from
07:44 : the other
07:45 : projects i have under this
07:47 : directory of which there are many
07:50 : so i'm actually gonna name it
07:52 : something that i um
07:59 : that helps me distinguish so i'm going
08:01 : to call this django
08:03 : demo
08:05 : or maybe can go tutorial
08:08 : django
08:10 : tut jingle tutorial how about that
08:14 : uh it's not oh it doesn't like dashes
08:17 : okay
08:18 : i'll do it underscore django underscore
08:20 : tut
08:23 : and i think it did it didn't spit out
08:25 : anything but it should have created a
08:27 : jango tut
08:29 : sub directory
08:33 : there it is okay and here's the code i'm
08:36 : going to use the atom text editor
08:42 : i don't need anything fancy
08:44 : i just need something that's simple and
08:46 : free
08:48 : so this is the code
08:51 : that it spit out it there looks like
08:53 : there's six python files in total
08:57 : and
09:00 : they have various roles
09:02 : in
09:04 : in the web application i'm sure
09:07 : let's keep going
09:10 : um
09:12 : where should this code live
09:16 : if your background is plain old php with
09:20 : no use of modern frameworks you're
09:22 : probably used to putting all the code
09:23 : under
09:25 : servers document root
09:28 : with django you don't do that so this is
09:30 : like when you use a web
09:33 : server like apache
09:35 : there's this
09:36 : slash var slash www directory you put
09:40 : everything
09:41 : all of your resources into but with
09:44 : django you don't do that um
09:48 : okay so it created these files uh that
09:51 : looks right
09:53 : that's basically what i have over here
09:56 : um
09:58 : the outer my site root directory is a
10:01 : container for your project
10:04 : mine is actually called django tut
10:08 : not my site so any anywhere in the
10:12 : tutorial that says my site i should
10:15 : mentally translate it to django tut
10:21 : manage that pi is a command line utility
10:24 : which i find
10:25 : refreshing because i like the fact that
10:28 : this this is
10:30 : like a command line tool that you run
10:33 : from the command line like you would
10:35 : do python manage that pi
10:38 : and then
10:40 : do you add various
10:42 : parameters such like run server i
10:44 : believe that that'll come later
10:46 : uh what i like about this is that
10:50 : this script is
10:53 : the contents of the script is
10:56 : shown to you
10:58 : so that it's not as mysterious as
11:03 : as some other frameworks that i have
11:05 : seen
11:10 : um execute from command line oh okay
11:14 : it's coming from this package here so if
11:16 : you care to know more about the details
11:19 : of what this script is doing
11:21 : you can dig into the source code
11:23 : inside this
11:25 : package
11:28 : um and then there's various files uh i'm
11:32 : gonna i'm impatient and i'm just gonna
11:34 : skip ahead okay
11:36 : um okay so what it's telling me to do
11:39 : now is to just go ahead and run this
11:42 : command
11:43 : so let's do that
11:45 : i already saw it
11:47 : coming so
11:48 : it says you have 18 un
11:50 : uh applied migrations i think that's
11:53 : actually okay
11:58 : it
11:59 : it doesn't say anything
12:01 : [Music]
12:03 : but the unapplied migrations will take
12:05 : care of that later and for now it's not
12:08 : hurting anything so but the the server
12:11 : is still
12:12 : running it still works
12:14 : and i think we can um go take a look at
12:18 : the result
12:19 : over on this url here so let's do that
12:25 : uh and there it is this web server
12:28 : that's running in my terminal is
12:30 : actually serving up
12:32 : this
12:33 : site here
12:35 : and it contains some links to the
12:38 : documentation
12:40 : but but basically
12:42 : that means that this installation of
12:45 : django worked
12:49 : um
12:51 : and and the the there's automatic hot
12:54 : code reloading which
12:57 : we haven't touched any code so
12:59 : but once we do touch the code it'll make
13:02 : it very convenient to
13:04 : change the app and re-test the app
13:08 : um and now we're gonna create the polls
13:11 : application which is the sample
13:13 : application
13:14 : we're gonna follow along and make
13:22 : okay
13:25 : we're going to use a utility that
13:26 : automatic
13:27 : so each application so we actually we
13:30 : have a project apparently
13:34 : but within a project you can have
13:36 : multiple applications
13:38 : and we're going to create an application
13:42 : within
13:44 : this project and the project is django
13:47 : tut
13:49 : as far as i understand so
13:52 : and there's a command for you to
13:54 : generate the directory of the project
13:58 : and we're going to use that and that
14:00 : command is python manage.py start app
14:05 : command it's the start app command and
14:07 : we're going to start an app called polls
14:11 : so let's go ahead and do that i'm gonna
14:13 : uh i'm gonna
14:17 : shut down the server now using control c
14:22 : and i'm gonna type this command
14:24 : python manage that pi start app and then
14:28 : pulse
14:31 : i think it did i think it did it it
14:33 : didn't tell me anything
14:35 : uh but it did create this pulse
14:39 : directory so
14:42 : which matches up with what the tutorial
14:45 : is telling me it's going to create this
14:47 : pulse directory and it's going to
14:48 : contain these things okay
14:51 : it looks like another six files
14:54 : and also a migrations folder
14:58 : okay
14:59 : and now we're supposed to write our
15:01 : first view
15:04 : a view
15:05 : as far as i understand is a
15:10 : some python code that serves up
15:13 : some
15:14 : http response uh which is to say serves
15:17 : up like usually a web page although
15:20 : there are some exceptions to that like
15:22 : if you go to a certain url
15:27 : that
15:28 : will ask a certain piece of python code
15:32 : a certain view more specifically
15:35 : to
15:36 : tell it what to render on this page and
15:39 : we're going to make one of those views
15:41 : so we're going to open up this file
15:43 : called polls slash views
15:46 : it's this one
15:48 : and then we're going to change the
15:49 : content to be like that
15:53 : this shortcuts import render thing
15:57 : we are not really using it but i'm gonna
15:59 : leave it there
16:00 : just in case and i'm gonna type
16:06 : up i know that i could just copy and
16:09 : paste this but uh when i'm learning
16:12 : something i prefer to type out
16:15 : uh things by hand especially it's if
16:17 : it's new to me
16:19 : and that way
16:21 : i can get the code
16:23 : into my
16:25 : fingers into my hands so to speak and
16:28 : it helps me
16:29 : with
16:32 : sort of ingesting the information and
16:34 : remembering it
16:37 : so i'm going to return a http response
16:41 : and i'm going to put some string uh i
16:44 : don't care to type that much so i'm just
16:46 : going to write hello world and
16:48 : stop at there
16:50 : and i think what this is gonna do is uh
16:53 : put hello world
16:55 : onto the web page uh this is the
16:57 : simplest view possible
17:00 : in django
17:01 : but in order to get it to call the view
17:03 : we actually need to wire up
17:06 : uh the url
17:08 : router
17:10 : which is
17:13 : oh which is doesn't even exist and we
17:16 : have to create that file under the polls
17:19 : directory so let's do that so under the
17:21 : polls directory
17:25 : i'm going to make a new file
17:27 : and call it urls.pi
17:30 : yep so this is a new file that i've just
17:33 : created here and i'm gonna
17:36 : put this
17:37 : code
17:38 : in here verbatim
17:44 : okay so from from the django.urls module
17:47 : we're going to import a function called
17:50 : path
17:52 : and then from that
17:54 : we're going to import views so that's
17:57 : just importing whatever this views
18:00 : created we're importing from it
18:04 : i think that means
18:06 : basically this index function we have
18:08 : access to it now
18:11 : uh yeah so when we're referencing views
18:14 : that index it's gonna reference uh this
18:16 : function over here
18:18 : and now i'm gonna set up url patterns
18:22 : which is a list
18:25 : of i would think url patterns
18:33 : and i know the tutorial uses uh single
18:36 : quotes
18:38 : i have a habit of using double quotes
18:41 : and i haven't bothered to change that
18:43 : habit so i'm just gonna use double quote
18:47 : um i don't care what you use
18:50 : okay
18:55 : okay so it's saying
18:57 : this is still not enough i have created
18:59 : these url patterns but we actually need
19:02 : to wire it up
19:04 : at the top level as well so the top
19:07 : level or at the yeah at the top level
19:10 : there's in inside the django tut
19:14 : directory or if you follow the direct
19:17 : the tutorial it would be my site
19:19 : there's another urls folder and we
19:22 : actually need to go in here
19:25 : and wire
19:26 : this up i need to connect
19:29 : the stuff we made
19:31 : in polls slash urls
19:34 : and we need to
19:35 : connect it up here
19:38 : by
19:41 : putting in another path definition here
19:46 : in
19:46 : oops polls
19:48 : inside their url patterns so it's like a
19:52 : nested url patterns with that within
19:54 : another url patterns
19:59 : okay so i think this include is
20:02 : basically referencing the one in here
20:06 : and say if it's if it's
20:09 : if the url if the url we type
20:13 : here starts with polls
20:16 : then
20:17 : we're gonna
20:19 : make use of this one that the the urls
20:22 : that's nested within the polls project
20:26 : and this include function where does it
20:29 : come from it comes from here so i need
20:31 : to add
20:32 : this include to the imports
20:36 : okay it talks about that here
20:39 : so
20:41 : yeah
20:43 : this include function seems to do a
20:46 : little bit of magic to
20:49 : take this path
20:51 : and sort of
20:54 : stick it in here in a sense
20:58 : and now we're ready to run the server
21:00 : again and see if those changes worked
21:03 : so python manage that py run server
21:10 : we still have these unapplied migrations
21:13 : uh we're still not going to worry about
21:15 : it for now
21:16 : but now we're going to go to this url
21:19 : let's open it in a new tab
21:22 : which is is
21:24 : i guess we could have typed it here and
21:26 : we get hello world so things worked
21:29 : this localhost or 127.0.0.1
21:33 : they mean the same thing they're
21:35 : interchangeable
21:37 : localhost might be easier to remember
21:40 : and then when we do slash polls
21:43 : then we
21:44 : we hit
21:46 : we hit this url pattern
21:49 : which in turn
21:51 : allows django to then
21:54 : refer to the urls here
21:57 : which is
22:00 : inside this file and then this is saying
22:02 : okay if i'm at the top level
22:05 : of
22:06 : slash polls
22:08 : this is there's nothing after slash
22:11 : pools
22:12 : then we're gonna use
22:14 : views.index and the name
22:16 : of this route is called index so
22:18 : views.index
22:20 : then goes into here goes into the views
22:23 : file
22:25 : and uh
22:27 : yeah and
22:28 : calls this index function and that's how
22:31 : we got uh this hello world returned back
22:35 : to django and django uh took the hello
22:38 : world string and send it to the server i
22:40 : mean send it to the browser
22:47 : okay and there
22:48 : this
22:49 : is
22:50 : more information about the path function
22:53 : that we are using to define our routes
22:57 : um but basically the first argument is
22:59 : the route
23:02 : which is a pattern uh and if it's empty
23:05 : string that just means nothing like but
23:08 : but if
23:09 : but if it's like a string
23:12 : with a slash that then it actually
23:15 : matches a part of
23:17 : the url that the user types into the
23:21 : to the browser
23:22 : address bar so this gets matched up and
23:25 : here that activates the second thing
23:28 : which is a the argument called view and
23:31 : the view is a
23:33 : locator
23:35 : for a specific view which
23:37 : eventually ends up
23:39 : being some python function that actually
23:42 : returns an http response
23:48 : okay so that was the part one uh of the
23:51 : tutorial um i will uh
23:54 : i will do the next part in a separate
23:56 : video uh if you're interested in
23:59 : continuing with the series then i will
24:02 : see you there