遇见Flask-Script
flask-script是flask的命令行扩展包,使用它可以通过命令行的形式操作flask项目, 例如,可通过命令启动一个发版本的服务器,设置数据库和定时任务等。
类似django的manage.py提供的命令,不同的是使用flask-script可以自定义更多的命令。
install flask-script
一般在虚拟环境中安装
(flask_env) mark@ocarina:~/pycharmprojects/flask_one$ pip install flask-script collecting flask-script downloading https://files.pythonhosted.org/packages/00/a4/cd587b2b19f043b65bf33ceda2f6e4e6cdbd0ce18d01a52b9559781b1da6/flask-script-2.0.6.tar.gz (43kb) 100% |████████████████████████████████| 51kb 229kb/s requirement already satisfied: flask in /home/mark/.virtualenvs/flask_env/lib/python3.6/site-packages (from flask-script) (1.0.2) requirement already satisfied: werkzeug>=0.14 in /home/mark/.virtualenvs/flask_env/lib/python3.6/site-packages (from flask->flask-script) (0.14.1) requirement already satisfied: itsdangerous>=0.24 in /home/mark/.virtualenvs/flask_env/lib/python3.6/site-packages (from flask->flask-script) (1.1.0) requirement already satisfied: click>=5.1 in /home/mark/.virtualenvs/flask_env/lib/python3.6/site-packages (from flask->flask-script) (7.0) requirement already satisfied: jinja2>=2.10 in /home/mark/.virtualenvs/flask_env/lib/python3.6/site-packages (from flask->flask-script) (2.10) requirement already satisfied: markupsafe>=0.23 in /home/mark/.virtualenvs/flask_env/lib/python3.6/site-packages (from jinja2>=2.10->flask->flask-script) (1.1.0) building wheels for collected packages: flask-script running setup.py bdist_wheel for flask-script ... done stored in directory: /home/mark/.cache/pip/wheels/1c/17/70/4598e6dba4bec58c1b59552c6409272aea31978ab8159f11a1 successfully built flask-script installing collected packages: flask-script successfully installed flask-script-2.0.6 (flask_env) mark@ocarina:~/pycharmprojects/flask_one$
使用flask-script
安装好了,不会用,怎么办?
在pycharm中点flask_script想进去看看,结果只进入了__init__.py中,看到如下内容:
class manager(object): """ controller class for handling a set of commands. typical usage:: class print(command): def run(self): print "hello" app = flask(__name__) manager = manager(app) manager.add_command("print", print()) if __name__ == "__main__": manager.run() on command line:: python manage.py print > hello :param app: flask instance, or callable returning a flask instance. :param with_default_commands: load commands **runserver** and **shell** by default. :param disable_argcomplete: disable automatic loading of argcomplete. """
使用方式一
导入flask_script中的manager,command
自定义的命令需要在command的子类中重写run方法,在此方法中定义命令需要做什么事
实例化manager(可以接收一个flask对象作为参数),调用manager对象的add_command('命令', 自定义命令类实例)
from flask_script import manager, command from app import app # flask对象 class testcommand(command): """ 测试命令 """ def run(self): # 重写command的run方法 # 使用命令在控制台输出信息 print("server run on xxx:80...") manager = manager(app) # 将flask_script与flask联系起来 manager.add_command('test', testcommand()) if __name__ == '__main__': manager.run()
在manage.py中执行manage.run()可以查看这个manage中包含的命令详情
/home/mark/.virtualenvs/flask_env/bin/python3.6 /home/mark/pycharmprojects/flask_one/manage.py usage: manage.py [-?] {test,shell,runserver} ... positional arguments: {test,shell,runserver} test 测试命令 shell runs a python shell inside flask application context. runserver runs the flask development server i.e. app.run() optional arguments: -?, --help show this help message and exit process finished with exit code 2
在命令行执行python manage.py test
(flask_env) mark@ocarina:~/pycharmprojects/flask_one$ python manage.py test server run on xxx:80...
使用方式二
导入flask_script中的manager,实例化之后使用@manager.command装饰器装饰一个函数,这样,这个函数名就成为一个命令,函数中的代码会在执行这个命令后执行。
from flask_script import manager from app import app manager = manager(app) @manager.command def music(): """ 小妞,给爷唱一个 """ print("客官不可以,不可以摸我那里....") if __name__ == '__main__': manager.run()
使用manager.run()查看
/home/mark/pycharmprojects/flask_one/manage.py usage: manage.py [-?] {music,shell,runserver} ... positional arguments: {music,shell,runserver} music 小妞,给爷唱一个 shell runs a python shell inside flask application context. runserver runs the flask development server i.e. app.run()
在命令行执行python manage.py music
(flask_env) mark@ocarina:~/pycharmprojects/flask_one$ python manage.py music 客官不可以,不可以摸我那里....
使用方式三
将命令定义在其他模块中,再引入到manage.py,将manage.py作为主命令模块。
from flask_script import manager # 不作为主命令模块,也就是说命令行是python manage.py xxx.. # 使用manage.py 而不是当前模块,这里的manager()就不用传如flask对象了 db_manager = manager() @db_manager.command def migrate(): """ 数据迁移命令 """ print("执行数据迁移...")
在manage.py中的引入方式:manger.add_command('prefix',manager对象)
from flask_script import manager from app import app from db_manager import db_manager manager = manager(app) # db是前缀 执行命令方式 python manage.py db migrate manager.add_command('db', db_manager) if __name__ == '__main__': manager.run()
执行结果:
(flask_env) mark@ocarina:~/pycharmprojects/flask_one$ python manage.py db migrate 执行数据迁移...
其他使用方式
可以使用manger.option()
装饰器
命令函数可以接收参数
弹出确认操作:
@db_manager.command def drop_data(): if prompt_bool("你真的要删除这些数据吗?后果自负哦..\t\n" "输入y删除,n取消"): print('数据已删除...') else: print("就知道你不敢") ---------------------------------------- (flask_env) mark@ocarina:~/pycharmprojects/flask_one$ python manage.py db drop_data 你真的要删除这些数据吗?后果自负哦.. 输入y删除,n取消 [n]: n 就知道你不敢 (flask_env) mark@ocarina:~/pycharmprojects/flask_one$
最后
上一篇: Vue实现模糊查询的简单方法实例
下一篇: 如何拍好风光摄影?风光摄影很容易吗?