[Flask] Flask extension

Flask extension

Flask is often referred to as a micro-framework because the core functions include Werkzeug- based WSGI and routing, and Jinja2- based template engine. In addition, the Flask framework also supports cookies and sessions, as well as JSON , static files and other web helpers. Obviously, this is not enough to develop a complete web application. The Flask extension has such a function . Flask extensions provide extensibility for the Flask framework.

There are a large number of Flask extensions available. A Flask extension is a Python module that adds specific types of support to Flask applications. The Flask Extension Registry (Flask Extension Registry) is a directory of available extensions. The required extension can be downloaded through the pip utility.

In this tutorial, we will discuss the following important Flask extensions:

• Flask Mail  -Provides an SMTP interface for Flask applications

• Flask WTF  -Add rendering and validation of WTForms

• Flask SQLAlchemy  -Add SQLAlchemy support to Flask applications

• Flask Sijax  -Sijax interface-Python/jQuery library, making AJAX easy to use in web applications

Each type of extension usually provides extensive documentation on its usage. Since the extension is a Python module, you need to import it to use it. The Flask extension is usually named flask-foo. The import operation is as follows:

from flask_foo import [class, function]

For Flask versions after 0.7, you can also use the syntax:

from flask.ext import foo

For this usage, the compatibility module needs to be activated. It can be installed by running flaskext_compat.py:

import flaskext_compat
flaskext_compat.activate()
from flask.ext import foo