87. flask-script component of flask, flaskflask-script

87. flask-script component of flask, flaskflask-script

The Flask Script extension provides the ability to insert external scripts to Flask, including running a development server, a custom Python shell, setting database scripts, cronjobs, and other command line Tasks running outside of web applications; Separate scripts from the system;

Flask Script works in a similar way as Flask itself. You only need to define and add commands called by the Manager instance from the command line;

Official documents: http://flask-script.readthedocs.io/en/latest/

1. Create and run commands

First, create a Python template to run the command script, which can be named manager. py;

In this file, there must be a Manager instance. The Manager class tracks the invocation of all the commands called in the command line and the handling process;

Manager has only one parameter-Flask instance, which can also be a function or another Flask instance returned;

Call manager. run () to start the Manager instance to receive commands from the command line;

#-*-coding:utf8-*-  from flask_script import Manager  from debug import app    manager = Manager(app)    if __name__ == '__main__':      manager.run() 

Create and add commands;

2. There are three methods to create a Command: Create a command subclass, use the @ Command modifier, and use the @ option modifier;

1) first -- create Command subclass

The Command subclass must define a run method;

For example, create the Hello command and add the Hello command to the Manager instance;

From flask_script import Manager, Serverfrom flask_script import Command from debug import app manager = Manager (app) class Hello (Command): 'Hello world' def run (self ): print 'Hello world' # custom command 1: manager. add_command ('hello', hello () # custom command 2: manager. add_command ("runserver", Server () # The command is runserverif _ name _ = '_ main _': manager. run ()

Run the following command:

Python manager. py hello
> Hello world

Python manager. py runserver
> Hello world

2) second -- use the @ Command modifier of the command instance

#-*-coding:utf8-*-  from flask_script import Manager  from debug import app    manager = Manager(app)   @manager.command  def hello():      'hello world'      print 'hello world'    if __name__ == '__main__':      manager.run() 

This method creates commands in the same way as the Command class;

Python manager. py hello
> Hello world

3) method 3: Use the @ option modifier of the Command instance

In complex cases, @ option is recommended;

There can be multiple @ option parameters;

From flask_script import Manager from debug import app manager = Manager (app) @ manager. option ('-n',' -- name', dest = 'name', help = 'your name', default = 'World') # Use-n, you can also use -- name, dest = "name" The name Of The command entered by the user as a parameter to pass to the name@manager.option in the function ('-U',' -- url ', dest = 'url', default = 'www .csdn.com ') # The command can either use-u or -- url, dest = "url" the url of the command entered by the user is passed to urldef hello (name, url) in the function as a parameter: 'Hello world or hello <setting name> 'print 'hello ', name print url if _ name _ = '_ main _': manager. run ()

Run as follows:

Python manager. py hello
> Hello world
> Www.csdn.com

Python manager. py hello-n sissiy-u www.sissiy.com
> Hello sissiy
> Www.sissiy.com

Python manager. py hello-name sissiy-url www.sissiy.com
> Hello sissiy
> Www.sissiy.com