1
1
2
Python Django Tutorial – What is Django? Contents Python Django Tutorial – What is Django? ............................................................................................... 1 Python Django Tutorial – Install Django ................................................................................................... 3 Python Django Tutorial – Serving a Request for a Website ...................................................................... 4 Python Django Tutorial – History .............................................................................................................. 5 Python Django Tutorial – MVT Pattern ..................................................................................................... 5 Python Django Tutorial – Features of Django ........................................................................................... 7 a. Scalability............................................................................................................................................ 8 b. Portability............................................................................................................................................ 8 c. Security ............................................................................................................................................... 8 d. Versatility............................................................................................................................................ 8 e. Packages ............................................................................................................................................. 8 f. Ease of Use .......................................................................................................................................... 9 Prerequisites to Creating a Project in Django ........................................................................................... 9 a. Starting Project..................................................................................................................................... 9 b. Running the Server............................................................................................................................... 9 c. Setting up a database .......................................................................................................................... 11 d. Web Server ....................................................................................................................................... 11 Django Project Structure......................................................................................................................... 11 a. manage.py ......................................................................................................................................... 12 b. Project folder ..................................................................................................................................... 13 c. db.sqlite3 ........................................................................................................................................... 14 Creating an Application........................................................................................................................... 14 Python Django Admin Interface .............................................................................................................. 16 How to Create Simple Project in Django? ............................................................................................... 18 Conclusion ............................................................................................................................................... 21
2
3
Django is a high-level Python framework. It is free and open-source, written in Python itself, and follows the model-view-template architectural pattern. We can use it to develop quality web applications faster and easier. Since developing for the web needs a set of similar components, you can use a framework. This way, you don’t have to reinvent the wheel. These tasks include authentication, forms, uploading files, management panels, and so.
Best Python Django Tutorial For Beginners Python Django Tutorial – Install Django To work with Django on your system, C:\Users\lifei>pip install Django Collecting Django
3
4
Let’s Explore Unique Features of Python Programming Language Downloading https://files.pythonhosted.org/packages/ab/15/cfde97943f 0db45e4f999c60b696fbb4df59e82bbccc686770f4e44c909 4/Django-2.0.7-py3-none-any.whl (7.1MB) 100% |████████████████████████████████| 7.1MB 610kB/s Requirement already satisfied: pytz in c:\users\lifei\appdata\local\programs\python\python36\lib\ site-packages (from django) (2018.5) Installing collected packages: django Successfully installed django-2.0.7 Python Django Tutorial – Serving a Request for a Website Let’s first find out, in layman’s terms, what happens when your server receives a request for a website. The request is passed to Django and that tries to analyze this request. The urlresolver tries to match the URL against a list of patterns. It performs this match from top to bottom. If it can find a match, it passes the request to the view, which is the associated function. The function view can check if the request is allowed. It 4
5
also generates a response, and then Django sends it to the user’s web browser. Python Django Tutorial – History
Adrian Holovaty and Simon Willison created Django in the fall of 2003 at the Lawrence Journal-World newspaper Django publicly released under a BSD license in July 2005; named after guitarist Django Reinhardt Today, Django is an open-source project with contributors around the world
Python Django Tutorial – MVT Pattern MVC stands for Model-View-Controller. We use this when we want to develop applications with user interfaces. MVT stands for Model-View-Template. A template is an HTML file mixed with DTL (Django Template Language). Django takes care of the Controller part, which is the software code and controls the interaction between the other two parts- Model and View. When a user requests for a resource, Django acts as a controller and checks if it is available. If the URL maps, View interacts with the Model and renders a Template. Python Django sends back a Template to the user as a response. 5
6
Read about Python Decision Making Statements with Syntax and Examples
Best Python Django Tutorial For Beginners The model helps us handle database. View executes business logic and interacts with Model to carry data. It also renders Template. Template handles the user interface and is a presentation layer. The Model class holds essential fields and methods. For each model class, we have a table in the database. Model is a subclass of django.db.models.Model. Each field here denotes a database field. With Django, we have a database-abstraction API that lets us perform CRUD (Create-Retrieve-Update-Delete) operations on mapped tables. 6
7
Python Django Tutorial – Features of Django When working with Python Django, you can expect the following Django Features-
Best Python Django Tutorial – Features of Django 7
8
a. Scalability When you need to scale your system, you can simply add more web nodes to your Django. That is, you can scale it horizontally. Two products that use Django’s scalability are Disqus and Instagram.
b. Portability The portability of Python makes for a portable Django too. Various platforms include Windows, Linux, and MacOS. c. Security Python Django ensures some arrangements for security too. One of these is that it stores hashed passwords in cookies. d. Versatility Python Django will work with formats like HTML, JSON, XML, among others. It also supports many different client-side frameworks. So, we can use it to build anything including regular websites and social networks. e. Packages
8
9
Django Programming has the foundation of thousands of additional packages. f. Ease of Use Features like the built-in admin interface make it easy to build with Django. It is also fully functional and finds it easy to switch databases. Prerequisites to Creating a Project in Django In this Python Django Tutorial, we will study the prerequisites to create a project in Python Django. a. Starting Project Use the following command in the command prompt to begin your projectC:\Users\lifei\Desktop>django-admin startproject project0 Then move to this folder. C:\Users\lifei\Desktop>cd project0 C:\Users\lifei\Desktop\project0> b. Running the Server You could apply these migrations before you start your serverC:\Users\lifei\Desktop\project0>python manage.py migrate 9
10
Now, start the serverC:\Users\lifei\Desktop\project0>python manage.py runserver Performing system checks… Have a look at Python Function Arguments with Types, Syntax, and Examples System check identified no issues (0 silenced). July 08, 2018 – 21:51:39 Django version 2.0.7, using settings ‘project0.settings’ Starting development server at http://127.0.0.1:8000/ Quit the server with CTRL-BREAK. If you see something like this, it means you have successfully installed Django:
10
11
Python Django Tutorial – Prerequisites to Creating a Project c. Setting up a database For our project, we have set up MySQL: http://www.mysql.com/ Python also supports other database products like Oracle, SQLite 3, MongoDB, PostgreSQL, and GoogleAppEngine Datastore. d. Web Server While Django has its own lightweight web server, you can also use your own- like Apache. Django Project Structure This is what your project directory will look like: 11
12
Python Django Tutorial – Project Structure Do you know the difference Between Python Generator vs Iterator a. manage.py This script lets us interact with our project using the command line. Facilities include starting up the server and syncing to the database.
12
13
Python Django Tutorial – manage.py b. Project folder This holds the packages for our project-
Python Django Tutorial – Project folder
__init__.py- A Python package. 13
14
settings.py- This holds website settings like database configuration details. urls.py- This holds links in your project and the function(s). wsgi.py- This deploys our project over WSGI and helps the app communicate with the web server. WSGI stands for Web Server Gateway Interface. __pycache__- This directory holds files like __init__.cpython-36.pyc, settings.cpython-36.pyc, urls.cpython-36.pyc, and wsgi.cpython-36.pyc. In settings.py, DEBUG is set to True. This is okay at the time of deployment, but you should set it to False when working with a live project. This is because this gives out information about errors in your project.
Another construct you will find in this file is1. DATABASES = { 2. 'default': { 3. 'ENGINE': 'django.db.backends.sqlite3', 4. 'NAME': os.path.join(BASE_DIR, 'db.sqlite3'), 5. } 6. } c. db.sqlite3 This is the database file for your project and has the extension .sqlite3. Creating an Application 14
15
Let’s learn how to create an application in Django by this python Django Tutorial. Projects are modular. A contact form is one such application, and you can borrow it from one project for another. You can start an application this way: C:\Users\lifei\Desktop\project0>python manage.py startapp app0 This creates the following contents in the directory project0:
Python Django Tutorial – Creating an Application
Python Django Tutorial – How to Create an Application
Migrations- This holds another __init__.py file. 15
16
__init__.py- This is a Python package. admin.py- This lets us make the app modifiable in the admin interface. apps.py- This holds the names of all your applications. models.py- This holds all application models. tests.py- This holds unit tests for the project. views.py- This holds the application views for the project.
Let’s prepare our self with Top 35 Python Interview Questions and Answers In your settings.py, you can add your app name in the INSTALLED_APPS construct1. INSTALLED_APPS = [ 2. 'django.contrib.admin', 3. 'django.contrib.auth', 4. 'django.contrib.contenttypes', 5. 'django.contrib.sessions', 6. 'django.contrib.messages', 7. 'django.contrib.staticfiles', 8. 'app0' 9. ] Python Django Admin Interface
16
17
Here, in this Python Django Tutorial, we are going to see how to use Django Admin Interface? Using the Django admin interface, you can perform CRUD operations on the model. This interface depends on the django.countrib model; it is enabled by default. You can find it as ‘django.contrib.admin’, in INSTALLED_APPS in settings.py. To access this interface, you can try one of two methods127.0.0.1:8000/admin localhost:8000/admin You get something like this:
Python Django Tutorial – Admin Interface Do you know What is Serialization in Python with Example 17
18
a. Creating a Superuser To create a superuser, you can push in the following commandpython manage.py createsuperuser Once you’re done creating a superuser, use this username and password to login to the dashboard.
Python Django Tutorial – How to Create a Super use
How to Create Simple Project in Django? We can create a simple view using the following code1. >>> from django.http import HttpResponse 2. >>> def hello(request): 3. return HttpResponse("Hello") 18
19
We save this file as views.py in the inner project0 directory. This is how we can import it1. >>> os.chdir('C:\\Users\\lifei\\Desktop\\project0') 2. >>> from project0.views import hello 3. a. Mapping to a URL Now in the inner project0 directory, you have a file urls.py. It looks something like this“””project0 URL Configuration The `urlpatterns` list routes URLs to views. For more information please see: https://docs.djangoproject.com/en/2.0/topics/http/urls/ Examples: Function views Add an import: from my_app import views Add a URL to urlpatterns: path(”, views.home, name=’home’) Class-based views Add an import: from other_app.views import Home Add a URL to urlpatterns: path(”, Home.as_view(), name=’home’) Including another URLconf Import the include() function: from django.urls import include, path 19
20
Add a URL to urlpatterns: path(‘blog/’, include(‘blog.urls’)) “””
1. >>> from django.contrib import admin 2. >>> from django.urls import path 3. >>> urlpatterns = [ 4. path('admin/', admin.site.urls), 5. ] In this, the urlpatterns tuple maps URLs to views. Add this line of import to urls.py: from project0.views import hello And then add this value to your urlpatterns tuple: 1. path('hello/',hello),
Best Python Django Tutorial – Mapping to a URL 20
21
Now, go to the following addresshttp://127.0.0.1:8000/hello/
Best Python Django Tutorial For Beginners So, this was all about Python Django Tutorial. Hope you like our explanation. Conclusion Hence, in this Python Django Tutorial, we get started with Django, a very common framework with Python. Here, we studied History & Features of Django. In addition, we cover the MVT Pattern, Prerequisites to create a Project, and many more. Still, you have a query regarding Python Django Tutorial, leave comments below.
21