数据库连接池

pip install DBUtils

模式：
   - 每个线程创建一个连接，关闭（默认不关闭），线程终止时，才关闭连接。
   - 创建共享连接池

应用：只要写原生SQL，用户数据框连接池

setting.py

from datetime import timedelta
from redis import Redis
import pymysql
from DBUtils.PooledDB import PooledDB, SharedDBConnection

class Config(object):
    DEBUG = True
    SECRET_KEY = "umsuldfsdflskjdf"
    PERMANENT_SESSION_LIFETIME = timedelta(minutes=20)
    SESSION_REFRESH_EACH_REQUEST= True
    SESSION_TYPE = "redis"
    PYMYSQL_POOL = PooledDB(
        creator=pymysql,  # 使用链接数据库的模块
        maxconnections=6,  # 连接池允许的最大连接数，0和None表示不限制连接数
        mincached=2,  # 初始化时，链接池中至少创建的空闲的链接，0表示不创建
        maxcached=5,  # 链接池中最多闲置的链接，0和None不限制
        maxshared=3,
        # 链接池中最多共享的链接数量，0和None表示全部共享。PS: 无用，因为pymysql和MySQLdb等模块的 threadsafety都为1，所有值无论设置为多少，_maxcached永远为0，所以永远是所有链接都共享。
        blocking=True,  # 连接池中如果没有可用连接后，是否阻塞等待。True，等待；False，不等待然后报错
        maxusage=None,  # 一个链接最多被重复使用的次数，None表示无限制
        setsession=[],  # 开始会话前执行的命令列表。如：["set datestyle to ...", "set time zone ..."]
        ping=0,
        # ping MySQL服务端，检查是否服务可用。# 如：0 = None = never, 1 = default = whenever it is requested, 2 = when a cursor is created, 4 = when a query is executed, 7 = always
        host='127.0.0.1',
        port=3306,
        user='root',
        password='123456',
        database='s8day127db',
        charset='utf8'
    )

class ProductionConfig(Config):
    SESSION_REDIS = Redis(host='192.168.0.94', port='6379')



class DevelopmentConfig(Config):
    SESSION_REDIS = Redis(host='127.0.0.1', port='6379')


class TestingConfig(Config):
    pass

utils/sql.py

import pymysql
from settings import Config
class SQLHelper(object):

    @staticmethod
    def open(cursor):
        POOL = Config.PYMYSQL_POOL
        conn = POOL.connection()
        cursor = conn.cursor(cursor=cursor)
        return conn,cursor

    @staticmethod
    def close(conn,cursor):
        conn.commit()
        cursor.close()
        conn.close()

    @classmethod
    def fetch_one(cls,sql,args,cursor =pymysql.cursors.DictCursor):
        conn,cursor = cls.open(cursor)
        cursor.execute(sql, args)
        obj = cursor.fetchone()
        cls.close(conn,cursor)
        return obj

    @classmethod
    def fetch_all(cls,sql, args,cursor =pymysql.cursors.DictCursor):
        conn, cursor = cls.open(cursor)
        cursor.execute(sql, args)
        obj = cursor.fetchall()
        cls.close(conn, cursor)
        return obj

views/__init__.py

from flask import Flask
from flask_session import Session
from .views import account
from .views import home

def create_app():
    app = Flask(__name__)
    app.config.from_object('settings.DevelopmentConfig')

    app.register_blueprint(account.account)
    app.register_blueprint(home.home)

    # 将session替换成redis session
    Session(app)

    return app

views/account.py

from flask import Blueprint,render_template,request,session,redirect
from ..utils.sql import SQLHelper
account = Blueprint('account',__name__)

from wtforms import Form
from wtforms.fields import simple,core,html5
from wtforms import validators
from wtforms import widgets

class LoginForm(Form):
    user = simple.StringField(
        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(),
        render_kw={'class': 'form-control'}

    )
    pwd = simple.PasswordField(
        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'}
    )

@account.route('/login',methods=['GET',"POST"])
def login():
    if request.method == 'GET':
        form = LoginForm()
        return render_template('login.html',form=form)

    form = LoginForm(formdata=request.form)
    if not form.validate():
        return render_template('login.html', form=form)

    obj = SQLHelper.fetch_one("select id,name from users where name=%(user)s and pwd=%(pwd)s", form.data)
    if obj:
        session.permanent = True
        session['user_info'] = {'id':obj['id'], 'name':obj['name']}
        return redirect('/index')
    else:
        return render_template('login.html',msg='用户名或密码错误',form=form)




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, '男'),
            (2, '女'),
        ),
        coerce=int
    )
    city = core.SelectField(
        label='城市',
        choices=SQLHelper.fetch_all('select id,name from city',{},None),
        # choices=(
        #     (1, '篮球'),
        #     (2, '足球'),
        # ),
        coerce=int
    )

    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.city.choices = SQLHelper.fetch_all('select id,name from city',{},None)


    def validate_name(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) # 当前name传过来的值
        # print(self.data) # 当前传过来的所有的值：name,gender.....

        obj = SQLHelper.fetch_one('select id from users where name=%s',[field.data,])
        if obj:
            raise validators.ValidationError("用户名已经存在") # 继续后续验证
            # raise validators.StopValidation("用户名已经存在") # 不再继续后续验证


@account.route('/register',methods=['GET','POST'])
def register():
    if request.method == 'GET':
        form = RegisterForm()
        return render_template('register.html',form=form)
    form = RegisterForm(formdata=request.form)
    if form.validate():
        print(form.data)
    else:
        print(form.errors)
    return "sdfasdfasdf"

views/home.py

from flask import Blueprint,render_template,request,session,redirect
home = Blueprint('home',__name__)


@home.route('/index')
def index():

    # user_info = session.get('user_info')
    # print(user_info)

    # session['user_info'] = {'k1':1,'k2':2}
    user_info = session.get('user_info') # {'k1':1,'k2':2}
    print('原来的值',user_info)
    session['user_info']['k1'] = 99999
    user_info = session.get('user_info')  # {'k1':1,'k2':2}
    print('修改之后的值',user_info)

    return "index"


@home.route('/test')
def test():
    user_info = session.get('user_info')
    print(user_info)
    return "test"

manage.py

from s8pro_flask import create_app
app = create_app()

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

目录结构