• 多app应用等系列汇总


    一. 多app应用

    from werkzeug.wsgi import DispatcherMiddleware
    from werkzeug.serving import run_simple
    from flask import Flask, current_app
    app1 = Flask('app01')
    app2 = Flask('app02')
    
    @app1.route('/index')
    def index():
        return "app01"
    
    @app2.route('/index2')
    def index2():
        return "app2"
    
    # http://www.oldboyedu.com/index
    # http://www.oldboyedu.com/sec/index2
    dm = DispatcherMiddleware(app1, {
        '/sec': app2,
    })
    
    if __name__ == "__main__":
        run_simple('localhost', 5000, dm)

    二 form表单

    安装:pip3 install wtforms

    使用1:

    from flask import Flask, render_template, request, redirect
    from wtforms import Form
    from wtforms.fields import simple
    from wtforms import validators
    from wtforms import widgets
    
    app = Flask(__name__, template_folder='templates')
    
    app.debug = True
    
    
    class LoginForm(Form):
        # 字段(内部包含正则表达式)
        name = simple.StringField(
            label='用户名',
            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')
            ],
            widget=widgets.TextInput(), # 页面上显示的插件
            render_kw={'class': 'form-control'}
    
        )
        # 字段(内部包含正则表达式)
        pwd = simple.PasswordField(
            label='密码',
            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-zd$@$!%*?&]{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')
    
            ],
            widget=widgets.PasswordInput(),
            render_kw={'class': 'form-control'}
        )
    
    
    
    @app.route('/login', methods=['GET', 'POST'])
    def login():
        if request.method == 'GET':
            form = LoginForm()
            return render_template('login.html', form=form)
        else:
            form = LoginForm(formdata=request.form)
            if form.validate():
                print('用户提交数据通过格式验证,提交的值为:', form.data)
            else:
                print(form.errors)
            return render_template('login.html', form=form)
    
    if __name__ == '__main__':
        app.run()

    login.html

    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
    </head>
    <body>
    <h1>登录</h1>
    <form method="post">
        <p>{{form.name.label}} {{form.name}} {{form.name.errors[0] }}</p>
    
        <p>{{form.pwd.label}} {{form.pwd}} {{form.pwd.errors[0] }}</p>
        <input type="submit" value="提交">
    </form>
    </body>
    </html>

    使用2:

    from flask import Flask, render_template, request, redirect
    from wtforms import Form
    from wtforms.fields import core
    from wtforms.fields import html5
    from wtforms.fields import simple
    from wtforms import validators
    from wtforms import widgets
    
    app = Flask(__name__, template_folder='templates')
    app.debug = True
    
    
    
    class RegisterForm(Form):
        name = simple.StringField(
            label='用户名',
            validators=[
                validators.DataRequired()
            ],
            widget=widgets.TextInput(),
            render_kw={'class': 'form-control'},
            default='alex'
        )
    
        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, ''),
                (2, ''),
            ),
            coerce=int # “1” “2”
         )
        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)
            self.favor.choices = ((1, '篮球'), (2, '足球'), (3, '羽毛球'))
    
        def validate_pwd_confirm(self, field):
            """
            自定义pwd_confirm字段规则,例:与pwd字段是否一致
            :param field:
            :return:
            """
            # 最开始初始化时,self.data中已经有所有的值
    
            if field.data != self.data['pwd']:
                # raise validators.ValidationError("密码不一致") # 继续后续验证
                raise validators.StopValidation("密码不一致")  # 不再继续后续验证
    
    
    @app.route('/register', methods=['GET', 'POST'])
    def register():
        if request.method == 'GET':
            form = RegisterForm(data={'gender': 2,'hobby':[1,]}) # initial
            return render_template('register.html', form=form)
        else:
            form = RegisterForm(formdata=request.form)
            if form.validate():
                print('用户提交数据通过格式验证,提交的值为:', form.data)
            else:
                print(form.errors)
            return render_template('register.html', form=form)
    
    
    
    if __name__ == '__main__':
        app.run()
    <!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 field in form %}
        <p>{{field.label}}: {{field}} {{field.errors[0] }}</p>
        {% endfor %}
        <input type="submit" value="提交">
    </form>
    </body>
    </html>

    三 sqlalchemy

    sqlalchemy是一个基于python实现的orm框架,该框架建立在DB API之上,使用关系对象映射进行数据库操作,简而言之:将类和对象转换成SQL,然后使用数据API执行SQL并获取执行结果

    pip install sqlalchemy

    组成部分:

    Engine, 框架
    Connection Pooling , 数据库连接池
    Dialect, 选择链接数据库的DB API种类
    Schema/Types, 架构和类型
    SQL Expression Language, SQL表达式语言

    orm的使用

    import datetime
    from sqlalchemy import create_engine
    from sqlalchemy.ext.declarative import declarative_base
    from sqlalchemy import Column, Integer, String, Text, ForeignKey, DateTime, UniqueConstraint, Index
    Base = declarative_base()
    
    class Users(Base):
        __tablename__ = 'users'  # 数据库表名称
        id = Column(Integer, primary_key=True)  # id 主键
        name = Column(String(32), index=True, nullable=False)  # name列,索引,不可为空
        # email = Column(String(32), unique=True)
        #datetime.datetime.now不能加括号,加了括号,以后永远是当前时间
        # ctime = Column(DateTime, default=datetime.datetime.now)
        # extra = Column(Text, nullable=True)
    
        __table_args__ = (
            # UniqueConstraint('id', 'name', name='uix_id_name'), #联合唯一
            # Index('ix_id_name', 'name', 'email'), #索引
        )
    
    def init_db():
        """
        根据类创建数据库表
        :return:
        """
        engine = create_engine(
            "mysql+pymysql://root:123456@127.0.0.1:3306/aaa?charset=utf8",
            max_overflow=0,  # 超过连接池大小外最多创建的连接
            pool_size=5,  # 连接池大小
            pool_timeout=30,  # 池中没有线程最多等待的时间,否则报错
            pool_recycle=-1  # 多久之后对线程池中的线程进行一次连接的回收(重置)
        )
    
        Base.metadata.create_all(engine)
    
    def drop_db():
        """
        根据类删除数据库表
        :return:
        """
        engine = create_engine(
            "mysql+pymysql://root:123456@127.0.0.1:3306/aaa?charset=utf8",
            max_overflow=0,  # 超过连接池大小外最多创建的连接
            pool_size=5,  # 连接池大小
            pool_timeout=30,  # 池中没有线程最多等待的时间,否则报错
            pool_recycle=-1  # 多久之后对线程池中的线程进行一次连接的回收(重置)
        )
    
        Base.metadata.drop_all(engine)
    
    if __name__ == '__main__':
        # drop_db()
        init_db()

    app.py

    from sqlalchemy.orm import sessionmaker
    from sqlalchemy import create_engine
    from models import Users
    #"mysql+pymysql://root@127.0.0.1:3306/aaa"
    engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/flask", max_overflow=0, pool_size=5)
    Connection = sessionmaker(bind=engine)
    
    # 每次执行数据库操作时,都需要创建一个Connection
    con = Connection()
    
    # ############# 执行ORM操作 #############
    obj1 = Users(name="lqz",age=123)
    con.add(obj1)
    # 提交事务
    con.commit()
    
    # 关闭session,其实是将连接放回连接池
    con.close()

    scop_session

    from sqlalchemy.orm import sessionmaker
    from sqlalchemy import create_engine
    from sqlalchemy.orm import scoped_session
    from models import Users
    
    engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/flask", max_overflow=0, pool_size=5)
    Session = sessionmaker(bind=engine)
    
    """
    # 线程安全,基于本地线程实现每个线程用同一个session
    # 特殊的:scoped_session中有原来方法的Session中的一下方法:
    
    public_methods = (
        '__contains__', '__iter__', 'add', 'add_all', 'begin', 'begin_nested',
        'close', 'commit', 'connection', 'delete', 'execute', 'expire',
        'expire_all', 'expunge', 'expunge_all', 'flush', 'get_bind',
        'is_modified', 'bulk_save_objects', 'bulk_insert_mappings',
        'bulk_update_mappings',
        'merge', 'query', 'refresh', 'rollback',
        'scalar'
    )
    """
    #scoped_session类并没有继承Session,但是却又它的所有方法
    session = scoped_session(Session)
    # ############# 执行ORM操作 #############
    obj1 = Users(name="jason")
    session.add(obj1)
    
    # 提交事务
    session.commit()
    # 关闭session
    session.close()

    一对多查询

    import time
    import threading
    
    from sqlalchemy.ext.declarative import declarative_base
    from sqlalchemy import Column, Integer, String, ForeignKey, UniqueConstraint, Index
    from sqlalchemy.orm import sessionmaker, relationship
    from sqlalchemy import create_engine
    from sqlalchemy.sql import text
    from sqlalchemy.engine.result import ResultProxy
    from models import Users, Hobby, Person
    
    engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/flask?charset=utf8", max_overflow=0, pool_size=5)
    Session = sessionmaker(bind=engine)
    session = Session()
    # 添加
    
    # session.add_all([
    #     Hobby(caption='乒乓球'),
    #     Hobby(caption='羽毛球'),
    #     Person(name='张三', hobby_id=1),
    #     Person(name='李四', hobby_id=2),
    # ])
    
    # person = Person(name='张九', hobby=Hobby(caption='姑娘'))
    # session.add(person)
    #添加二
    # hb = Hobby(caption='人妖')
    # hb.pers = [Person(name='文飞'), Person(name='博雅')]
    # session.add(hb)
    #
    # session.commit()
    """
    
    # 使用relationship正向查询
    """
    # v = session.query(Person).first()
    # print(v.name)
    # print(v.hobby.caption)
    """
    
    # 使用relationship反向查询
    """
    # v = session.query(Hobby).first()
    # print(v.caption)
    # print(v.pers)
    
    #方式一,自己链表
    # person_list=session.query(Person).join(Hobby,isouter=True)
    # print(person_list)
    # person_list=session.query(Person,Hobby).join(Hobby,isouter=True)
    # print(person_list)
    # for row in person_list:
    #     # print(row.name,row.caption)
    #     print(row[0].name,row[1].caption)
    #
    # #方式二:通过relationship
    #
    person_list=session.query(Person).all()
    for row in person_list:
        print(row.name,row.hobby.caption)
    # #查询喜欢姑娘的所有人
    # obj=session.query(Hobby).filter(Hobby.id==1).first()
    # persons=obj.pers
    # print(persons)
    # session.close()
    #如果没有建立外键
    
    # ret = session.query(Person).join(Hobby,Person.nid==Hobby.id, isouter=True)
    # print(ret)

    单表查询

    import time
    import threading
    from sqlalchemy.ext.declarative import declarative_base
    from sqlalchemy import Column, Integer, String, ForeignKey, UniqueConstraint, Index
    from sqlalchemy.orm import sessionmaker, relationship
    from sqlalchemy import create_engine
    from sqlalchemy.sql import text
    
    from models import Users
    engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/flask", max_overflow=0, pool_size=5)
    Session = sessionmaker(bind=engine)
    
    session = Session()
    # 条件
    # ret = session.query(Users).filter_by(name='lqz').all()
    #表达式,and条件连接
    # ret = session.query(Users).filter(Users.id > 7, Users.name == 'jason').all()
    # print(ret)
    # ret = session.query(Users).filter(Users.id.between(3, 5), Users.name == 'jason').all()
    # print(ret)
    #注意下划线
    # ret = session.query(Users).filter(Users.id.in_([1,3,4])).all()
    # print(ret)
    #~非,除。。外
    # ret = session.query(Users).filter(~Users.id.in_([1,3,4])).all()
    # print(ret)
    
    # #二次筛选
    # ret = session.query(Users).filter(Users.id.in_(session.query(Users.id).filter_by(name='jason'))).all()
    # print(ret)
    from sqlalchemy import and_, or_
    #or_包裹的都是or条件,and_包裹的都是and条件
    #ret = session.query(Users).filter(and_(Users.id > 3, Users.name == 'eric')).all()
    # ret = session.query(Users).filter(or_(Users.id >6 , Users.name == 'jason')).all()
    # print(ret)
    # ret = session.query(Users).filter(
    #     or_(
    #         Users.id < 2,
    #         and_(Users.name == 'eric', Users.id > 3),
    #         Users.age != ""
    #     )).all()
    
    
    # 通配符,以e开头,不以e开头
    # ret = session.query(Users).filter(Users.name.like('_q%')).all()
    # print(ret)
    # ret = session.query(Users).filter(~Users.name.like('j%')).all()
    # print(ret)
    
    # 限制,用于分页,区间
    # ret = session.query(Users)[1:9]
    # print(ret)
    #
    # # 排序,根据name降序排列(从大到小)
    # ret = session.query(Users).order_by(Users.name.desc())
    # print(ret)
    
    
    # #第一个条件重复后,再按第二个条件升序排
    # ret = session.query(Users).order_by(Users.name.desc(), Users.id.asc())
    # print(ret)
    #
    # # 分组
    from sqlalchemy.sql import func
    #
    # ret = session.query(Users).group_by(Users.name).all()
    # print(ret)
    # #分组之后取最大id,id之和,最小id
    # ret = session.query(
    #     func.max(Users.id),
    #     func.sum(Users.id),
    #     func.min(Users.id)).group_by(Users.name).all()
    # print(ret)
    # #haviing筛选
    # ret = session.query(
    # #     func.max(Users.id),
    # #     func.sum(Users.id),
    # #     func.min(Users.id)).group_by(Users.name).having(func.min(Users.id) >2)
    # # print(ret)

    增删改

    import time
    import threading
    
    from sqlalchemy.ext.declarative import declarative_base
    from sqlalchemy import Column, Integer, String, ForeignKey, UniqueConstraint, Index
    from sqlalchemy.orm import sessionmaker, relationship
    from sqlalchemy import create_engine
    from sqlalchemy.sql import text
    
    from models import Users
    engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/flask", max_overflow=0, pool_size=5)
    Session = sessionmaker(bind=engine)
    
    session = Session()
    
    # ################ 添加 ################
    
    # obj1 = Users(name="wupeiqi",age=40)
    # session.add(obj1)
    #
    # session.add_all([
    #     Users(name="tank"),
    #     Users(name="jason"),
    #     #Hosts(name="c1.com"),
    # ])
    # session.commit()
    
    
    # ################ 删除 ################
    
    # session.query(Users).filter(Users.id == 5).delete()
    # session.commit()
    
    # ################ 修改 ################
    
    #传字典
    #session.query(Users).filter(Users.id ==4 ).update({"age" : 30,})
    #类似于django的F查询
    #session.query(Users).filter(Users.id == 3).update({Users.name: Users.name + "sb"}, synchronize_session=False)
    #session.query(Users).filter(Users.id == 7).update({"age": Users.age + 16}, synchronize_session="evaluate")
    # session.commit()
    
    # ################ 查询 ################
    
    # r1 = session.query(Users).all()
    # print(r1)
    #只取age列,把name重命名为xx
    # r2 = session.query(Users.name.label('sb'), Users.age).filter(Users.id==8).first()
    # print(r2.sb)
    #filter传的是表达式,filter_by传的是参数
    # r3 = session.query(Users).filter(Users.name == "jason").all()
    # print(r3)
    # r4 = session.query(Users).filter_by(name='jason').all()
    # print(r4)
    # r5 = session.query(Users).filter_by(name='lqz').first()
    #:value 和:name 相当于占位符,用params传参数
    #r6 = session.query(Users).filter(text("id<:value and name=:name")).params(value=224, name='fred').order_by(Users.id).all()
    #自定义查询sql
    #r7 = session.query(Users).from_statement(text("SELECT * FROM users where name=:name")).params(name='ed').all()
    
    
    #增,删,改都要commit()
    session.close()

    多对多

    import time
    import threading
    
    from sqlalchemy.ext.declarative import declarative_base
    from sqlalchemy import Column, Integer, String, ForeignKey, UniqueConstraint, Index
    from sqlalchemy.orm import sessionmaker, relationship
    from sqlalchemy import create_engine
    from sqlalchemy.sql import text
    from sqlalchemy.engine.result import ResultProxy
    from models import Users,  Hobby, Person, Girl, Boy2Girl, Boy
    
    engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/flask?charset=utf8", max_overflow=0, pool_size=5)
    Session = sessionmaker(bind=engine)
    session = Session()
    # 添加
    
    # session.add_all([
    #     Girl(name='c1.com'),
    #     Girl(name='c2.com'),
    #     Boy(hostname='A组'),
    #     Boy(hostname='B组'),
    # ])
    # session.commit()
    
    # s2g = Boy2Girl(girl_id=1,boy_id=1)
    # session.add(s2g)
    # session.commit()
    #
    #
    # gp = Girl(name='C组')
    # gp.boys = [Boy(hostname='c3.com'),Boy(hostname='c4.com')]
    # session.add(gp)
    # session.commit()
    #
    #
    # ser = Boy(hostname='c6.com')
    # ser.girl = [Girl(name='F组'),Girl(name='G组')]
    # session.add(ser)
    # session.commit()
    
    
    
    # 使用relationship正向查询
    
    # v = session.query(Boy).first()
    # print(v.hostname)
    # print(v.girl)
    
    
    # 使用relationship反向查询
    
    # v = session.query(Girl).first()
    # print(v.name)
    # print(v.boys)
    #
    #
    #
    # session.close()
    生前无需久睡,死后自会长眠,努力解决生活中遇到的各种问题,不畏将来,勇敢面对,加油,你是最胖的,哈哈哈
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  • 原文地址:https://www.cnblogs.com/panshao51km-cn/p/11864743.html
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