flask10--數據庫鏈接池(通用),wtforms

一.數據庫連接池

pymsql鏈接數據庫

import pymysql

conn = pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='123456', db='s8day127db')
cursor = conn.cursor(cursor=pymysql.cursors.DictCursor)
# cursor.execute("select id,name from users where name=%s and pwd=%s",['lqz','123',])
cursor.execute("select id,name from users where name=%(user)s and pwd=%(pwd)s",{'user':'lqz','pwd':'123'})
obj = cursor.fetchone()
conn.commit()
cursor.close()
conn.close()

print(obj)

數據庫連接池版

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,  # 使用鏈接數據庫的模塊
        maxconnections=6,  # 連接池允許的最大連接數，0和None表示不限制連接數
        mincached=2,  # 初始化時，鏈接池中至少創建的空閑的鏈接，0表示不創建
        maxcached=5,  # 鏈接池中最多閑置的鏈接，0和None不限制
        maxshared=3,
        # 鏈接池中最多共享的鏈接數量，0和None表示全部共享。PS: 無用，因為pymysql和MySQLdb等模塊的 threadsafety都為1，所有值無論設置為多少，_maxcached永遠為0，所以永遠是所有鏈接都共享。
        blocking=True,  # 連接池中如果沒有可用連接后，是否阻塞等待。True，等待；False，不等待然后報錯
        maxusage=None,  # 一個鏈接最多被重復使用的次數，None表示無限制
        setsession=[],  # 開始會話前執行的命令列表。如：["set datestyle to ...", "set time zone ..."]
        ping=0,
        # ping MySQL服務端，檢查是否服務可用。# 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

使用：

obj = SQLHelper.fetch_one("select id,name from users where name=%(user)s and pwd=%(pwd)s", form.data)

二.wtforms

安裝: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（內部包含正則表達式）
    name = simple.StringField(
        label='用戶名',
        validators=[
            validators.DataRequired(message='用戶名不能為空.'),
            validators.Length(min=6, max=18, message='用戶名長度必須大於%(min)d且小於%(max)d')
        ],
        widget=widgets.TextInput(), # 頁面上顯示的插件
        render_kw={'class': 'form-control'}

    )
    # 字段（內部包含正則表達式）
    pwd = simple.PasswordField(
        label='密碼',
        validators=[
            validators.DataRequired(message='密碼不能為空.'),
            validators.Length(min=8, message='用戶名長度必須大於%(min)d'),
            validators.Regexp(regex="^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[$@$!%*?&])[A-Za-z\d$@$!%*?&]{8,}",
                              message='密碼至少8個字符，至少1個大寫字母，1個小寫字母，1個數字和1個特殊字符')

        ],
        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('用戶提交數據通過格式驗證，提交的值為：', 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>登錄</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='用戶名',
        validators=[
            validators.DataRequired()  #如何自定義過濾類？看源碼模仿
        ],
        widget=widgets.TextInput(),
        render_kw={'class': 'form-control'},
        default='alex'
    )

    pwd = simple.PasswordField(
        label='密碼',
        validators=[
            validators.DataRequired(message='密碼不能為空.')
        ],
        widget=widgets.PasswordInput(),
        render_kw={'class': 'form-control'}
    )

    pwd_confirm = simple.PasswordField(
        label='重復密碼',
        validators=[
            validators.DataRequired(message='重復密碼不能為空.'),
            validators.EqualTo('pwd', message="兩次密碼輸入不一致")
        ],
        widget=widgets.PasswordInput(),
        render_kw={'class': 'form-control'}
    )

    email = html5.EmailField(
        label='郵箱',
        validators=[
            validators.DataRequired(message='郵箱不能為空.'),
            validators.Email(message='郵箱格式錯誤')
        ],
        widget=widgets.TextInput(input_type='email'),
        render_kw={'class': 'form-control'}
    )

    gender = core.RadioField(
        label='性別',
        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='愛好',
        choices=(
            (1, '籃球'),
            (2, '足球'),
        ),
        coerce=int
    )

    favor = core.SelectMultipleField(
        label='喜好',
        choices=(
            (1, '籃球'),
            (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, '籃球'), (2, '足球'), (3, '羽毛球'))

    def validate_pwd_confirm(self, field):
        """
        自定義pwd_confirm字段規則，例：與pwd字段是否一致
        :param field:
        :return:
        """
        # 最開始初始化時，self.data中已經有所有的值

        if field.data != self.data['pwd']:
            # raise validators.ValidationError("密碼不一致") # 繼續后續驗證
            raise validators.StopValidation("密碼不一致")  # 不再繼續后續驗證


@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('用戶提交數據通過格式驗證，提交的值為：', form.data)
        else:
            print(form.errors)
        return render_template('register.html', form=form)



if __name__ == '__main__':
    app.run()
Copy<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1>用戶注冊</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>