flask-自定义命令、多APP应用、 wtforms、sqlalcchemy
一、flask-script 自定义命令
类似于django的命令行启动项目（python3 manage.py runserver）
首先安装 pip3 install flask-script
使用 (注意我这里的文件名取shell-ma,文件名随便取)
from flask import Flask from flask_script import Manager app = Flask(__name__) manager=Manager(app) @app.route("/") def index(): return "ok" if __name__ == '__main__': manager.run() 注意：启动命令行在Terminal中输入(前提需要在正确的路径下) python shell-ma.py runserver 这样项目就启动了，我们可以访问'/'路径
自定制命令启动
from flask import Flask from flask_script import Manager app = Flask(__name__) manager=Manager(app) @manager.command 相当于位置传参 def custom(arg): """ 启动命令行 python shell-ma.py custom 123 """ print(arg) #arg打印的就是传入的123 @manager.option('-n', '--name', dest='name') 相当于关键字传参 @manager.option('-u', '--url', dest='url') def cmd(name, url): """ 自定义命令（-n也可以写成--name） 执行： python manage.py cmd -n lqz -u aa 执行： python manage.py cmd --name lqz --url bb """ print(name, url) if __name__ == '__main__': manager.run()
二、多app应用（了解）
from werkzeug.wsgi import DispatcherMiddleware from werkzeug.serving import run_simple from flask import Flask app1 = Flask('app01') app2 = Flask('app02') @app1.route('/index') def index(): return "app01" @app2.route('/index') def index2(): return "app2" dm = DispatcherMiddleware(app1, { '/sec12': app2, }) if __name__ == "__main__": run_simple('localhost', 5000, dm)
注意：访问app01路径：127.0.0.1:5000/index
访问app02路径：127.0.0.1:5000/sec/index2
三、wtforms
安装 pip3 install wtforms
简单使用
forms.py
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__) 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=2, max=6, 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='密码长度必须大于%(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') ], 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>
选项，下拉框等forms应用
forms.py
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): 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 print(field.data) if field.data !="sb": #raise validators.ValidationError("sb") # 继续后续验证 raise validators.StopValidation("SB") # 不再继续后续验证 # 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 name = simple.StringField( label='用户名', validators=[ validators.DataRequired() ], widget=widgets.TextInput(), render_kw={'class': 'form-control'}, default='tank' ) 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=[ validate_pwd_confirm, 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 # “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')) self.favor.data=[1,] @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()
register.html
<!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>
四、sqlalcchemy介绍
1、介绍
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，简言之便是：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。
安装 pip3 install sqlalchemy
组成部分
Engine，框架的引擎
Connection Pooling ，数据库连接池
Dialect，选择连接数据库的DB API种类
Schema/Types，架构和类型
SQL Exprression Language，SQL表达式语言
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 from sqlalchemy.orm import relationship 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) age = Column(Integer,default=0) #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 __repr__(self): return self.name class Hobby(Base): __tablename__ = 'hobby' id = Column(Integer, primary_key=True) caption = Column(String(50), default='篮球') class Person(Base): __tablename__ = 'person' nid = Column(Integer, primary_key=True) name = Column(String(32), index=True, nullable=True) # hobby指的是tablename而不是类名， hobby_id = Column(Integer, ForeignKey("hobby.id")) # 跟数据库无关，不会新增字段，只用于快速链表操作 # 类名，backref用于反向查询,uselist=False hobby = relationship('Hobby', backref='pers') def __repr__(self): return self.name class Boy2Girl(Base): __tablename__ = 'boy2girl' id = Column(Integer, primary_key=True, autoincrement=True) girl_id = Column(Integer, ForeignKey('girl.id')) boy_id = Column(Integer, ForeignKey('boy.id')) class Girl(Base): __tablename__ = 'girl' id = Column(Integer, primary_key=True) name = Column(String(64), unique=True, nullable=False) class Boy(Base): __tablename__ = 'boy' id = Column(Integer, primary_key=True, autoincrement=True) hostname = Column(String(64), unique=True, nullable=False) # 与生成表结构无关，仅用于查询方便,放在哪个单表中都可以 girl = relationship('Girl', secondary='boy2girl', backref='boys') def init_db(): """ 根据类创建数据库表 :return: """ engine = create_engine( "mysql+pymysql://root:123@127.0.0.1:3306/flask?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:123@127.0.0.1:3306/flask?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()
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()
2、scoped_session
基于scoped_session实现线程安全
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/s6", 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="alex1") session.add(obj1) # 提交事务 session.commit() # 关闭session session.close()
3、表操作增删改
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 db import Users, Hosts engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/s6", max_overflow=0, pool_size=5) Session = sessionmaker(bind=engine) session = Session() # ################ 添加 ################ """ obj1 = Users(name="wupeiqi") session.add(obj1) session.add_all([ Users(name="lqz"), Users(name="egon"), Hosts(name="c1.com"), ]) session.commit() """ # ################ 删除 ################ """ session.query(Users).filter(Users.id > 2).delete() session.commit() """ # ################ 修改 ################ """ #传字典 session.query(Users).filter(Users.id > 0).update({"name" : "lqz"}) #类似于django的F查询 session.query(Users).filter(Users.id > 0).update({Users.name: Users.name + "099"}, synchronize_session=False) session.query(Users).filter(Users.id > 0).update({"age": Users.age + 1}, synchronize_session="evaluate") session.commit() """ # ################ 查询 ################ """ r1 = session.query(Users).all() #只取age列，把name重命名为xx r2 = session.query(Users.name.label('xx'), Users.age).all() #filter传的是表达式，filter_by传的是参数 r3 = session.query(Users).filter(Users.name == "lqz").all() r4 = session.query(Users).filter_by(name='lqz').all() 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()
常用操作
# 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 > 1, Users.name == 'eric').all() ret = session.query(Users).filter(Users.id.between(1, 3), Users.name == 'eric').all() #注意下划线 ret = session.query(Users).filter(Users.id.in_([1,3,4])).all() #~非，除。。外 ret = session.query(Users).filter(~Users.id.in_([1,3,4])).all() #二次筛选 ret = session.query(Users).filter(Users.id.in_(session.query(Users.id).filter_by(name='eric'))).all() 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 < 2, Users.name == 'eric')).all() ret = session.query(Users).filter( or_( Users.id < 2, and_(Users.name == 'eric', Users.id > 3), Users.extra != "" )).all() # 通配符，以e开头，不以e开头 ret = session.query(Users).filter(Users.name.like('e%')).all() ret = session.query(Users).filter(~Users.name.like('e%')).all() # 限制，用于分页，区间 ret = session.query(Users)[1:2] # 排序，根据name降序排列（从大到小） ret = session.query(Users).order_by(Users.name.desc()).all() #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()).all() # 分组 from sqlalchemy.sql import func ret = session.query(Users).group_by(Users.extra).all() #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() #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).all() # 连表（默认用forinkey关联） ret = session.query(Users, Favor).filter(Users.id == Favor.nid).all() #join表，默认是inner join ret = session.query(Person).join(Favor).all() #isouter=True 外连，表示Person left join Favor，没有右连接，反过来即可 ret = session.query(Person).join(Favor, isouter=True).all() #打印原生sql aa=session.query(Person).join(Favor, isouter=True) print(aa) # 自己指定on条件（连表条件）,第二个参数，支持on多个条件，用and_,同上 ret = session.query(Person).join(Favor,Person.id==Favor.id, isouter=True).all() # 组合（了解）UNION 操作符用于合并两个或多个 SELECT 语句的结果集 #union和union all的区别？ q1 = session.query(Users.name).filter(Users.id > 2) q2 = session.query(Favor.caption).filter(Favor.nid < 2) ret = q1.union(q2).all() q1 = session.query(Users.name).filter(Users.id > 2) q2 = session.query(Favor.caption).filter(Favor.nid < 2) ret = q1.union_all(q2).all()
4一对多
表关系
class Hobby(Base): __tablename__ = 'hobby' id = Column(Integer, primary_key=True) caption = Column(String(50), default='篮球') class Person(Base): __tablename__ = 'person' nid = Column(Integer, primary_key=True) name = Column(String(32), index=True, nullable=True) # hobby指的是tablename而不是类名，uselist=False hobby_id = Column(Integer, ForeignKey("hobby.id")) # 跟数据库无关，不会新增字段，只用于快速链表操作 # 类名，backref用于反向查询 hobby=relationship('Hobby',backref='pers')
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 db import Users, Hosts, Hobby, Person engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/s6?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=3), Person(name='李四', hobby_id=4), ]) 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(models.Person.name,models.Hobby.caption).join(models.Hobby,isouter=True).all() person_list=session.query(models.Person,models.Hobby).join(models.Hobby,isouter=True).all() 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(models.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(models.Hobby).filter(models.Hobby.id==1).first() persons=obj.pers print(persons) session.close()
5、多对多
表关系
class Boy2Girl(Base): __tablename__ = 'boy2girl' id = Column(Integer, primary_key=True, autoincrement=True) girl_id = Column(Integer, ForeignKey('girl.id')) boy_id = Column(Integer, ForeignKey('boy.id')) class Girl(Base): __tablename__ = 'girl' id = Column(Integer, primary_key=True) name = Column(String(64), unique=True, nullable=False) class Boy(Base): __tablename__ = 'boy' id = Column(Integer, primary_key=True, autoincrement=True) hostname = Column(String(64), unique=True, nullable=False) # 与生成表结构无关，仅用于查询方便,放在哪个单表中都可以 servers = relationship('Girl', secondary='boy2girl', backref='boys')
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 db import Users, Hosts, Hobby, Person, Group, Server, Server2Group engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/s6?charset=utf8", max_overflow=0, pool_size=5) Session = sessionmaker(bind=engine) session = Session() # 添加 """ session.add_all([ Server(hostname='c1.com'), Server(hostname='c2.com'), Group(name='A组'), Group(name='B组'), ]) session.commit() s2g = Server2Group(server_id=1, group_id=1) session.add(s2g) session.commit() gp = Group(name='C组') gp.servers = [Server(hostname='c3.com'),Server(hostname='c4.com')] session.add(gp) session.commit() ser = Server(hostname='c6.com') ser.groups = [Group(name='F组'),Group(name='G组')] session.add(ser) session.commit() """ # 使用relationship正向查询 """ v = session.query(Group).first() print(v.name) print(v.servers) """ # 使用relationship反向查询 """ v = session.query(Server).first() print(v.hostname) print(v.groups) """ session.close()
6、flask-migrate
flask和SQLAchemy的管理者，通过他把他们做连接
db = SQLAlchemy() - 包含配置 - 包含ORM基类 - 包含create_all - engine - 创建连接
flask-migrate
python3 manage.py db init 初始化：只执行一次
python3 manage.py db migrate 等同于 makemigartions
python3 manage.py db upgrade 等同于migrate
