Building Web Applications with Flask

Chapter 3. Man, Do I Like Templates!

As stated previously, Flask gives you the VC of MVC out-of-the-box. In this chapter, we will discuss what Jinja2 is, and how Flask uses Jinja2 to implement the View layer and awe you. Be prepared!

What is Jinja2 and how is it coupled with Flask?

Jinja2 is a library found at http://jinja.pocoo.org/; you can use it to produce formatted text with bundled logic. Unlike the Python format function, which only allows you to replace markup with variable content, you can have a control structure, such as a for loop, inside a template string and use Jinja2 to parse it. Let's consider this example:

from jinja2 import Template x = """ <p>Uncle Scrooge nephews</p> <ul> {% for i in my_list %} <li>{{ i }}</li> {% endfor %} </ul> ...