遇見Flask-Script
阿新 • • 發佈:2018-12-28
Flask-Script是Flask的命令列擴充套件包,使用它可以通過命令列的形式操作Flask專案, 例如,可通過命令啟動一個發版本的伺服器,設定資料庫和定時任務等。
類似Django的manage.py提供的命令,不同的是使用flask-script可以自定義更多的命令。
Install flask-script
一般在虛擬環境中安裝
(flask_env) [email protected]:~/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) [email protected]:~/PycharmProjects/flask_one$
使用flask-script
安裝好了,不會用,怎麼辦?
在pycharm中點flask_script想進去看看,結果只進入了__init__.py中,看到如下內容:
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
匯入flask_script中的Manager,Command
自定義的命令需要在Command的子類中重寫run方法,在此方法中定義命令需要做什麼事
例項化Manager(可以接收一個Flask物件作為引數),呼叫Manager物件的add_command('命令', 自定義命令類例項)
from flask_script import Manager, Command from app import app # Flask物件 class TestCommand(Command): """ 測試命令 """ def run(self): # 重寫Command的run方法 # 使用命令在控制檯輸出資訊 print("server run on xxx:80...") manager = Manager(app) # 將flask_script與Flask聯絡起來 manager.add_command('test', TestCommand()) if __name__ == '__main__': manager.run()
在manage.py中執行manage.run()可以檢視這個manage中包含的命令詳情
/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 測試命令
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
在命令列執行python manage.py test
(flask_env) [email protected]:~/PycharmProjects/flask_one$ python manage.py test
server run on xxx:80...
使用方式二
匯入flask_script中的Manager,例項化之後使用@manager.command裝飾器裝飾一個函式,這樣,這個函式名就成為一個命令,函式中的程式碼會在執行這個命令後執行。
from flask_script import Manager
from app import app
manager = Manager(app)
@manager.command
def music():
"""
小妞,給爺唱一個
"""
print("客官不可以,不可以摸我那裡....")
if __name__ == '__main__':
manager.run()
使用manager.run()檢視
/home/mark/PycharmProjects/flask_one/manage.py
usage: manage.py [-?] {music,shell,runserver} ...
positional arguments:
{music,shell,runserver}
music 小妞,給爺唱一個
shell Runs a Python shell inside Flask application context.
runserver Runs the Flask development server i.e. app.run()
在命令列執行python manage.py music
(flask_env) [email protected]:~/PycharmProjects/flask_one$ python manage.py music
客官不可以,不可以摸我那裡....
使用方式三
將命令定義在其他模組中,再引入到manage.py,將manage.py作為主命令模組。
from flask_script import Manager
# 不作為主命令模組,也就是說命令列是python manage.py xxx..
# 使用manage.py 而不是當前模組,這裡的Manager()就不用傳如Flask物件了
db_manager = Manager()
@db_manager.command
def migrate():
"""
資料遷移命令
"""
print("執行資料遷移...")
在manage.py中的引入方式:manger.add_command('prefix',manager物件)
from flask_script import Manager
from app import app
from db_manager import db_manager
manager = Manager(app)
# db是字首 執行命令方式 python manage.py db migrate
manager.add_command('db', db_manager)
if __name__ == '__main__':
manager.run()
執行結果:
(flask_env) [email protected]:~/PycharmProjects/flask_one$ python manage.py db migrate
執行資料遷移...
其他使用方式
可以使用manger.option()
裝飾器
命令函式可以接收引數
彈出確認操作:
@db_manager.command
def drop_data():
if prompt_bool("你真的要刪除這些資料嗎?後果自負哦..\t\n"
"輸入y刪除,n取消"):
print('資料已刪除...')
else:
print("就知道你不敢")
----------------------------------------
(flask_env) [email protected]:~/PycharmProjects/flask_one$ python manage.py db drop_data
你真的要刪除這些資料嗎?後果自負哦..
輸入y刪除,n取消 [n]: n
就知道你不敢
(flask_env) [email protected]:~/PycharmProjects/flask_one$