标签:range wtforms 数据库连接 default utf-8 关系 sub widget turn
用于实现类似于django中 python3 manage.py runserver ...类似的命令。
安装
pip3 install flask-script
使用:
from flask_script import Manager app = Flask(__name__) manager=Manager(app)
@app.route("/")
def index()
return "hello world"
if __name__ == ‘__main__‘: manager.run() #以后在执行,直接:python3 manage.py runserver #python3 manage.py runserver --help
启动服务器
from flask_script import Manager from flask import Flask # 安装pip3 install flask-script app = Flask(__name__) manager = Manager(app) @app.route("/") def index(): return "hello world" @manager.command def func(arg,a): print(arg,a) @manager.option(‘-n‘,‘--name‘,dest=‘name‘) @manager.option(‘-u‘,‘--url‘,dest=‘url‘) def cmd(name,url): """ 自定义命令(-n也可以写成--name) 执行:python3 manage.py cmd -n jack -u http://www.baidu.com 执行: python manage.py cmd --name lqz --url http://www.oldboyedu.com :param name: :param url: :return: """ print(name,url) if __name__ == ‘__main__‘: manager.run()
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)
分析
路由的访问
表单验证
pip3 install wtforms
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()
<!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>
效果:
邮箱,单选框,多选框,下拉选框,全局钩子校验密码的实现。
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=‘Eason‘ ) 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()
<!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>
前台渲染效果
学习内容:
1、介绍
2、简单使用(能创建表,删除表,不能修改表)
3、一对多的关系
4、多对多关系
5、操作数据表
6、基于scoped_session实现线程安全
7、基本的增删改查
8、常用的操作
9、执行原生的mysql
10、一对多
11、多对多
12、Flask-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
重要的参数说明
#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
SQLAlchemy本身无法操作数据库,其必须以来pymsql等第三方插件,Dialect用于和数据API进行交流,
根据配置文件的不同调用不同的数据库API,从而实现对数据库的操作,如:
MySQL-Python mysql+mysqldb://<user>:<password>@<host>[:<port>]/<dbname> pymysql mysql+pymysql://<username>:<password>@<host>/<dbname>[?<options>] MySQL-Connector mysql+mysqlconnector://<user>:<password>@<host>[:<port>]/<dbname>
执行原生sql(不常用)
import time import threading import sqlalchemy from sqlalchemy import create_engine from sqlalchemy.engine.base import Engine engine = create_engine( "mysql+pymysql://root:123456@127.0.0.1:3306/test?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) ) def task(arg): conn = engine.raw_connection() cursor = conn.cursor() cursor.execute( "select * from app01_book" ) result = cursor.fetchall() print(result) cursor.close() conn.close() for i in range(20): t = threading.Thread(target=task, args=(i,)) t.start()
models.py
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()
app.py
操作数据库
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="jack",age=20) 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()
关于数据库连接时每次都要提交commint带来的线程安全问题
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()
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="Eason",age=20) # 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()
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)
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()
flask和SQLAchemy的管理者,通过它吧他们连接起来。
flask多依赖于第三方软件,想使用就先安装:
安装:
pip3 install flask_sqlAchemy
重要参数:
""" db = SQLAlchemy() - 包含配置 - 包含ORM基类 - 包含create_all - engine - 创建连接 """
通过配置设置实现和Django一样,可以用命令makegirations来迁移数据库数据。
#!/usr/bin/env python # -*- coding:utf-8 -*- class BaseConfig(object): # SESSION_TYPE = ‘redis‘ # session类型为redis # SESSION_KEY_PREFIX = ‘session:‘ # 保存到session中的值的前缀 # SESSION_PERMANENT = True # 如果设置为False,则关闭浏览器session就失效。 # SESSION_USE_SIGNER = False # 是否对发送到浏览器上 session:cookie值进行加密 SQLALCHEMY_DATABASE_URI = "mysql+pymysql://root:123@127.0.0.1:3306/flask01?charset=utf8" SQLALCHEMY_POOL_SIZE = 5 SQLALCHEMY_POOL_TIMEOUT = 30 SQLALCHEMY_POOL_RECYCLE = -1 # 追踪对象的修改并且发送信号 SQLALCHEMY_TRACK_MODIFICATIONS = False class ProductionConfig(BaseConfig): pass class DevelopmentConfig(BaseConfig): pass class TestingConfig(BaseConfig): pass
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
标签:range wtforms 数据库连接 default utf-8 关系 sub widget turn
原文地址:https://www.cnblogs.com/Gaimo/p/11863287.html