color version - PET: Python Entre Todos - Python Argentina

The Django package includes:
For example, if we want to get all users that are 20 years old, it could be dome through
some code like this:
past_teens = User.objects.filter(age = 20)
[while we are at it: Django’s built-in authentication application already includes a User
class that we can take advantage of :)]
The first tool Django provides is an “Object Relational Mapper” (ORM). The ORM will
allow us to interact with the database so it will be one of the two things that we will
commonly use the most (so pay attention, this is like something that will be in the final
for sure).
Like we are using object-oriented programming, we are going to define and use classes.
Like most commonly used databases are relational databases, Django will take care of
translating our operations on objects into SQL statements that will run on the databases’
tables.
For example: we define our class User with several properties (name, address, email,
etc.). We can then do things like create instances of User, store values in its properties
and tell it: “hey, you, save yourself!”, Django will automagically create the appropriate
update or insert SQL statement and run it in the database.
The code for this example could look like this:
new_user = User()
new_user.name = 'Fisa'
new_user.email = 'fisadev@gmail.com'
new_user.address = 'somewhere in Argentina'
new_user.save()
We can now write code that reads from and stores stuff into the database, but that is not
of much use to the user. We have to show him something. The second toll we’re going to
use is the templates system.
What’s that It is what will let us “inject” our data into HTML (or XML, or whatever)
templates that we define.
That is to say that we’ll build the HTML for the user to see in their browser but we’ll say
within the file things like “here goes the name of the current user”.
The template language also provides some basic logic structures that we can use like
loops, conditionals and even some kind of template inheritance.
Just like this, the ORM allows also us to read from the database, filter, run complex
queries, etc.