Flask-session
Flask-session跟框架自带的session有什么区别呢~
框架自带的session是通过请求上下文~放入到Local中的~那如果我们想把session放入别的地方怎么办呢~~
比如redis~或者数据库~等等~~Flask-session就提供了这些功能~~我们看下Flask-session怎么用~~
一、下载安装
pip install flask-session
二、导入并实例化
from flask_session import Session
from flask import Flask
def create_app():
app = Flask(__name__)
app.config.from_object("settings.DevConfig")
Session(app)
app.register_blueprint(userBlue)
return app
三、配置文件
class BaseConfig(object): # Flask-Session 第三步 # SESSION_TYPE = ‘redis‘ # SESSION_REDIS = Redis(host=‘192.168.0.94‘, port=‘6379‘)
实现原理
回顾一下session的实现原理~请求进来先把request以及session封装到RequestContext对象中~~
然后调用push方法通过LocalStark放入到Local中~这时候放入到Local中的session还是空的~
然后调用了session_interface中的open_session 以及save_session方法~~
那我们再看下~~Flask-session都做了什么~~
修改了app.session_interface这个类~所以在我们调用open_session以及save_session的时候~调用的是我们配置的类里的方法~
从而实现了session存储地方的不同~
Flask SQLAlchemy
学习Flask-SQLAlchemy之前~大家要先学习一下SQLAlchemy~一个Python的ORM框架~~
接下来是Flask-SQLAlchemy的应用~~
一、下载安装
pip3 install flask-sqlalchemy
二、导入并实例化SQLAlchemy
# 在跟项目同名的文件夹下的 init.py中 from flask_sqlalchemy import SQLAlchemy db = SQLAlchemy() from .views.user import us # !!! 注意事项 # 必须在导入蓝图之前
三、初始化
def create_app(): app = Flask(__name__) app.config.from_object("settings.BaseConfig") app.register_blueprint(us) # Flask-Session 第二步实例化session Session(app) # 初始化db db.init_app(app) return app
四、在配置文件写入配置信息
class BaseConfig(object): # Flask-Session 第三步 # SESSION_TYPE = ‘redis‘ # SESSION_REDIS = Redis(host=‘192.168.0.94‘, port=‘6379‘) SQLALCHEMY_DATABASE_URI = "mysql+pymysql://root:root1234@127.0.0.1:3306/code_record?charset=utf8" SQLALCHEMY_POOL_SIZE = 10 SQLALCHEMY_MAX_OVERFLOW = 5 # SQLALCHEMY_TRACK_MODIFICATIONS = False pass
五、创建model
# by gaoxin from sqlalchemy import Column, Integer, String from flask_demo import db class Users(db.Model): __tablename__ = ‘users‘ id = Column(Integer, primary_key=True) name = Column(String(32), index=True, nullable=False)
六、生成表（需要使用app上下文）
# by gaoxin from flask_demo import db, create_app from flask_demo.models import *
# 一定要导入models 否则找不到表创建不出来 app = create_app() app_ctx = app.app_context() with app_ctx: db.create_all() # db.drop_all()
七、基于ORM对数据库操作
# by gaoxin from flask import Blueprint from flask_demo import db from flask_demo.models import Users us = Blueprint("us", __name__) @us.route("/index") def index(): # db.session.add(Users(name="gaoxin")) # db.session.commit() # db.session.remove() ret = db.session.query(Users).all() print(ret) db.session.remove() return "Index"
Flask-Script
一、下载安装
pip3 install flask-script
二、增加的功能 runserver
# by gaoxin from flask_demo import create_app from flask_script import Manager app = create_app() manager = Manager(app) if __name__ == ‘__main__‘: # app.run() manager.run() # 启动命令变成 # python3 manager.py runserver -h 127.0.0.1 -p 8000 # Running on http://127.0.0.1:8000/ (Press CTRL+C to quit)
三、自定义命令
# by gaoxin from flask_demo import create_app from flask_script import Manager app = create_app() manager = Manager(app) # 位置传参 @manager.command def custom(arg): """ 自定义命令 python manage.py custom 123 :param arg: :return: """ print(arg) # 关键字传参 @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 gaoxin -u http://www.oldboyedu.com :param name: :param url: :return: """ print(name, url) if __name__ == ‘__main__‘: # app.run() manager.run()
Flask-migrate
一、下载安装
pip3 install flask-migrate
二、增加的命令
！！！！ 依赖flask-script ！！！！
# by gaoxin from flask_demo import create_app, db from flask_demo.models import * 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 # 依赖 flask-script python manage.py db init # 初始化 python manage.py db migrate # makemigrations python manage.py db upgrade # migrate """ manager.add_command("db", MigrateCommand) if __name__ == ‘__main__‘: # app.run() manager.run()
wtforms
类比我们django的Form组件~
Form组件的主要应用是~帮助我们自动生成HTML，以及做表单数据的验证~~
用法跟Form组件大同小异~~
一、下载安装
pip3 install wtforms
二、自动生成HTML
第一步 生成一个Form类
第二步 实例化这个Form类，把这个实例化对象当成参数传递给前端
# 视图页面
from wtforms import Form, widgets, validators
from wtforms.fields import simple
class MyForm(Form): name = simple.StringField( label="用户名", render_kw={"placeholder": "请输入用户名"}, widget=widgets.TextArea(), default="gaoxin" ) pwd = simple.PasswordField() @ac.route("/login", methods=["GET", "POST"]) def login(): if request.method == "GET": form = MyForm(data={"name": "gao"}) return render_template("login.html", form=form)
<!--html页面--> <form action="" novalidate> 用户名： {{form.name}} 密码： {{form.pwd}} <button type="submit">提交</button> </form> <!--循环出来的页面--> <form action=""> {% for field in form %} {{field.label}}: {{field}} {% endfor %} <button type="submit">提交</button> </form>
三、验证
第一步 在Form类中增加验证信息
第二步 在视图中做数据的校验 并且页面展示错误信息
# 视图页面 class MyForm(Form): name = simple.StringField( label="用户名", render_kw={"placeholder": "请输入用户名"}, # widget=widgets.TextArea(), validators=[ validators.DataRequired(message="用户名不能为空"), validators.Length(min=6, max=18, message=‘用户名长度必须大于%(min)d且小于%(max)d‘) ], # default="gaoxin" ) pwd = simple.PasswordField( label="密码", widget=widgets.PasswordInput(), validators=[ validators.DataRequired(message=‘密码不能为空.‘), validators.Length(min=8, message=‘用户名长度必须大于%(min)d‘), validators.Regexp(regex="^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[$@$!%*?&])[A-Za-z\d$@$!%*?&]{8,}", message=‘密码至少8个字符，至少1个大写字母，1个小写字母，1个数字和1个特殊字符‘) ] ) @ac.route("/login", methods=["GET", "POST"]) def login(): if request.method == "GET": form = MyForm(data={"name": "gao"}) return render_template("login.html", form=form) form = MyForm(formdata=request.form) if form.validate(): print(form.data) else: return render_template("login.html", form=form) return "lakdsjlga"
<!--循环出来的页面--> <form action="" method="post" novalidate> {% for field in form %} {{field.label}}: {{field}} {{field.errors[0]}} {% endfor %} <button type="submit">提交</button> </form>
四、拓展字段
以用户注册为例，输入用户名，密码，重复密码，性别和爱好。
class RegisterForm(Form): name = simple.StringField( label=‘用户名‘, validators=[ validators.DataRequired() ], widget=widgets.TextInput(), # render_kw={‘class‘: ‘form-control‘}, default=‘gaoxin‘ ) pwd = simple.PasswordField( label=‘密码‘, validators=[ validators.DataRequired(message=‘密码不能为空.‘) ], widget=widgets.PasswordInput(), # render_kw={‘class‘: ‘form-control‘} ) pwd_confirm = simple.PasswordField( label=‘重复密码‘, validators=[ validators.DataRequired(message=‘重复密码不能为空.‘), validators.EqualTo(‘pwd‘, message="两次密码输入不一致") ], widget=widgets.PasswordInput(), render_kw={‘class‘: ‘form-control‘} ) email = html5.EmailField( label=‘邮箱‘, validators=[ validators.DataRequired(message=‘邮箱不能为空.‘), validators.Email(message=‘邮箱格式错误‘) ], widget=widgets.TextInput(input_type=‘email‘), render_kw={‘class‘: ‘form-control‘} ) gender = core.RadioField( label=‘性别‘, choices=( (1, ‘男‘), (2, ‘女‘), ), coerce=int ) city = core.SelectField( label=‘城市‘, choices=( (‘bj‘, ‘北京‘), (‘sh‘, ‘上海‘), ) ) hobby = core.SelectMultipleField( label=‘爱好‘, choices=( (1, ‘篮球‘), (2, ‘足球‘), ), coerce=int ) favor = core.SelectMultipleField( label=‘喜好‘, choices=( (1, ‘篮球‘), (2, ‘足球‘), ), widget=widgets.ListWidget(prefix_label=False), option_widget=widgets.CheckboxInput(), coerce=int, default=[1, 2] ) def __init__(self, *args, **kwargs): super(RegisterForm, self).__init__(*args, **kwargs) # 从数据库获取数据 做到实时更新 self.favor.choices = ((1, ‘篮球‘), (2, ‘足球‘), (3, ‘羽毛球‘)) @ac.route(‘/register‘, methods=[‘GET‘, ‘POST‘]) def register(): if request.method == ‘GET‘: form = RegisterForm(data={‘gender‘: 1}) return render_template(‘register.html‘, form=form) else: form = RegisterForm(formdata=request.form) if form.validate(): return "注册成功" else: print(form.errors) return render_template(‘register.html‘, form=form)
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> </head> <body> <h1>用户注册</h1> <form method="post" novalidate style="padding:0 50px"> {% for item in form %} <p>{{item.label}}: {{item}} {{item.errors[0] }}</p> {% endfor %} <input type="submit" value="提交"> </form> </body> </html>
！！! 注意选项字段需要去数据库取数据 还有就是从数据库取数据的实时更新
