P7 Day1 get to know the flask framework

1.1Flask Introduce

Flask Born in 2010 year , Use python Language based Werkzeug The lightweight tool box Web Development framework
Flask Itself is equivalent to a kernel , Almost all other functions need to be extended ( mail :Flask-Mail, User authentication :Flask-Login, database :Flask-SQLAlchemy).
Flask The core of Werkzeug( Routing module ), Jinja2 template engine .
Flask Of " light "
Flask Of " light ", Does not mean that its function is not powerful enough , Flask With rich extensions , It relies on extensions to add functionality to applications , Many plug-ins provide database integration , Form validation , Upload processing , Various open authentication technologies , Flask These characteristics make it in web Development has become very popular
# Be careful : If you build a large project , Use many extensions , Flask Will also change with Django Same weight .

Preparation before installation

install Flask

Install in the black window

pip install flask==1.1.4

Build a virtual environment

Within the project


Click ok to complete
Then start the virtual environment at the terminal
activate start-up
（ When typing, you can click tab Automatic completion ）

After starting, you have to return

decativate.bat It's closing

Installation dependent

After configuring the virtual environment, you should also configure the dependencies required for installation
First import what you want to install , Then open the terminal for automatic installation .
It's fine too pip install Manual installation

Flask To configure

Create within the project app.py File
Note that it can only be app.py file name ,app2.py The file name cannot be recognized

Load... From the configuration object
create a file , Configure objects inside flask To configure

Load configuration from file
create a file , Direct configuration

Factory model and APP Encapsulation and Flask route

create a file
Packaging function

Create another file to import and execute

Another way to open