Django

 What is Django and also describe history of Django?

Django was invented by Lawrence Journal-World in 2003, to meet the short deadlines in the newspaper and at the same time meeting the demands of experienced web developers. Simon Willison and Adrian Holovaty began using python to build application.

1. Initial release to the public was in July 2005.
2. And the latest version of Django is 4.0.3 (March 2022).  Django is a Python framework that makes it easier to create web sites using Python.
3. Django takes care of the difficult stuff so that you can concentrate on building your web applications.
4. Django emphasizes reusability of components, also referred to as DRY (Don't Repeat Yourself), and comes with ready-to-use features like login system, database connection and CRUD operations (Create Read Update Delete).

Note:- Django is especially helpful for database driven websites.

Some points on which Django works:

Django follows the MVT design pattern which is  (Model View Template).

1. Model - The data you want to present, usually data from a database.
2. View - A request handler that returns the relevant template and content - based on the request from the user.
3. Template - A text file (like an HTML file) containing the layout of the web page, with logic on how to display the data.

What is Model?

The Model provides data from the database .

• In Django, the data is delivered as an  (ORM) Object Relational Mapping , which is a technique designed to make it easier to work with databases .
• The most common way to extract data from a database is SQL (Structured Query Language) . One problem with SQL is that you have to have a pretty good understanding of the database structure to be able to work with it.
• Django, with ORM Object Relational Mapping , makes it easier to communicate with the database, without having to write complex SQL statements.
• The models are usually located in a file called models.py.

What is Model?

• A view is a function or method that takes http requests as arguments, imports the relevant model(s) , and finds out what data to send to the template, and returns the final result.
• The views are usually located in a file called views.py .

What is Templaet?

• Template is a file where you describe how the result should be represented.
• Templates are often .html files, with HTML (Hyper Text Markup Language)  code describing the layout of a web page, but it can also be in other file formats to present other results, but we will concentrate on .html files .
• Django uses standard HTML( Hyper text markup language)  to describe the layout, but uses Django tags to add logic :

<h1> My Homepages </h1>

<p>My name is {{ firstname }}.</p>

 Templates of an application is located in a folder named Templates . 

What is Django URLs:

1. Django also provides a way to navigate around the different pages in a website.
2. When a user requests a URL, Django decides which view it will send it to.
3. This is done in a file called urls.py .