python框架-Flask第三方组件

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1. flask-sqlalchemy

a. 下载安装

pip3 install flask-sqlalchemy

b. init__.py

			导入并实例化SQLAlchemy
			from flask_sqlalchemy import SQLAlchemy
			db = SQLAlchemy()
			
			注意事项：
				 - 必须在导入蓝图之前
				 - 必须导入models.py 

c. 初始化

db.init_app(app)

d. 在配置文件中写入配置

			# ##### SQLALchemy配置文件 #####
			SQLALCHEMY_DATABASE_URI = "mysql+pymysql://root:[email protected]:3306/db?charset=utf8"
			SQLALCHEMY_POOL_SIZE = 10
			SQLALCHEMY_MAX_OVERFLOW = 5

e. 创建models.py中的类（对应数据库表）

models.py

				from sqlalchemy.ext.declarative import declarative_base
				from sqlalchemy import Column
				from sqlalchemy import Integer,String,Text,Date,DateTime
				from sqlalchemy import create_engine
				from twiss import db


				class Users(db.Model):
					__tablename__ = 'users'

					id = Column(Integer, primary_key=True)
					name = Column(String(32), index=True, nullable=False)
					depart_id = Column(Integer)

f. 生成表（使用app上下文）

			from twiss import db,create_app

			app = create_app()
			app_ctx = app.app_context() # app_ctx = app/g
			with app_ctx: # __enter__,通过LocalStack放入Local中
				db.create_all() # 调用LocalStack放入Local中获取app，再去app中获取配置

g. 基于ORM对数据库进行操作。

			from flask import Blueprint
			from twiss import db
			from twiss import models
			us = Blueprint('us',__name__)


			@us.route('/index')
			def index():
				# 使用SQLAlchemy在数据库中插入一条数据
				# db.session.add(models.Users(name='gkate',depart_id=1))
				# db.session.commit()
				# db.session.remove()
				result = db.session.query(models.Users).all()
				print(result)
				db.session.remove()

				return 'Index'

2. flask-script

		pip3 install flask-script 

功能：

a. 增加 runserver

				from twiss import create_app
				from flask_script import Manager


				app = create_app()
				manager = Manager(app)

				if __name__ == '__main__':
					# app.run()
					manager.run()

b. 位置传参

				from twiss import create_app
				from flask_script import Manager


				app = create_app()
				manager = Manager(app)

				@manager.command
				def custom(arg):
					"""
					自定义命令
					python manage.py custom 123
					:param arg:
					:return:
					"""
					print(arg)


				if __name__ == '__main__':
					# app.run()
					manager.run()

c. 关键字传参

				from twiss import create_app
				from flask_script import Manager


				app = create_app()
				manager = Manager(app)

				@manager.option('-n', '--name', dest='name')
				@manager.option('-u', '--url', dest='url')
				def cmd(name, url):
					"""
					自定义命令
					执行： python manage.py  cmd -n twiss -u http://www.gkate.com
					:param name:
					:param url:
					:return:
					"""
					print(name, url)


				if __name__ == '__main__':
					# app.run()
					manager.run()
	

3. flask-migrate

		pip3 install flask-migrate 
		依赖：flask-script 
	
			#!/usr/bin/env python
			# -*- coding:utf-8 -*-

			from sansa import create_app
			from sansa import db

			from flask_script import Manager
			from flask_migrate import Migrate, MigrateCommand

			app = create_app()
			manager = Manager(app)
			Migrate(app, db)

			"""
			# 数据库迁移命名
				python manage.py db init
				python manage.py db migrate
				python manage.py db upgrade
			"""
			manager.add_command('db', MigrateCommand)


			if __name__ == '__main__':
				manager.run()
				# app.run()

4. 找到项目使用的所有组件和版本。

		pip install pipreqs
		
		pipreqs ./ --encoding=utf-8 

5. 虚拟环境

		pip3 install virtualenv
		
		
		virtualenv env1  --no-site-packages
		
		activate
		deactivate