Flask_____

flask-session

作用:将默认保存的签名cookie中的值 保存到 redis/memcached/file/Mongodb/SQLAlchemy

安装:pip3 install flask-session

使用1:

from flask import Flask,session
from flask_session import RedisSessionInterface
import redis
app = Flask(__name__)
conn=redis.Redis(host='127.0.0.1',port=6379)
#use_signer是否对key签名
app.session_interface=RedisSessionInterface(conn,key_prefix='lqz')
@app.route('/')
def hello_world():
    session['name']='lqz'
    return 'Hello World!'

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

使用2:

from redis import Redis
from flask.ext.session import Session
app.config['SESSION_TYPE'] = 'redis'
app.config['SESSION_REDIS'] = Redis(host='192.168.0.94',port='6379')
Session(app)

问题:设置cookie时,如何设定关闭浏览器则cookie失效。

response.set_cookie('k','v',exipre=None)#这样设置即可
#在session中设置
app.session_interface=RedisSessionInterface(conn,key_prefix='lqz',permanent=False)
#一般不用,我们一般都设置超时时间,多长时间后失效

问题:cookie默认超时时间是多少?如何设置超时时间

#源码expires = self.get_expiration_time(app, session)
'PERMANENT_SESSION_LIFETIME':           timedelta(days=31),#这个配置文件控制

数据库连接池

pymsql链接数据库

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)

数据库连接池版

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

使用:

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

wtforms

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()

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>

信号

Flask框架中的信号基于blinker,其主要就是让开发者可是在flask请求过程中定制一些用户行为

安装:pip3 install blinker

内置信号:

request_started = _signals.signal('request-started')                # 请求到来前执行
request_finished = _signals.signal('request-finished')              # 请求结束后执行
 
before_render_template = _signals.signal('before-render-template')  # 模板渲染前执行
template_rendered = _signals.signal('template-rendered')            # 模板渲染后执行
 
got_request_exception = _signals.signal('got-request-exception')    # 请求执行出现异常时执行
 
request_tearing_down = _signals.signal('request-tearing-down')      # 请求执行完毕后自动执行(无论成功与否)
appcontext_tearing_down = _signals.signal('appcontext-tearing-down')# 应用上下文执行完毕后自动执行(无论成功与否)
 
appcontext_pushed = _signals.signal('appcontext-pushed')            # 应用上下文push时执行
appcontext_popped = _signals.signal('appcontext-popped')            # 应用上下文pop时执行
message_flashed = _signals.signal('message-flashed')                # 调用flask在其中添加数据时,自动触发

使用信号:

from flask import Flask,signals,render_template

app = Flask(__name__)

# 往信号中注册函数
def func(*args,**kwargs):
    print('触发型号',args,kwargs)
signals.request_started.connect(func)

# 触发信号: signals.request_started.send()
@app.before_first_request
def before_first1(*args,**kwargs):
    pass
@app.before_first_request
def before_first2(*args,**kwargs):
    pass

@app.before_request
def before_first3(*args,**kwargs):
    pass

@app.route('/',methods=['GET',"POST"])
def index():
    print('视图')
    return render_template('index.html')


if __name__ == '__main__':
    app.wsgi_app
    app.run()
-内置信号:
    #第一步,编写一个函数
    def func(*
args,**kwargs):
        print('触发信号',args,kwargs)
    #第二步:注册信号
    #signals.request_started.connect(func)
    signals.request_finished.connect(func)
 
-自定义信号:
    #第一步:定义信号
    aaa = _signals.signal('aaa')
    #第二步:编写函数,绑定信息
    def func(*args,**kwargs):
        print('信号',args,kwargs)
    #第三步,绑定函数
    aaa.connect(func)
    #触发信号
    aaa.send('123123',k1='v1')

自定义信号(了解):

from flask import Flask, current_app, flash, render_template
from flask.signals import _signals
app = Flask(import_name=__name__)

# 自定义信号
xxxxx = _signals.signal('xxxxx')
 
def func(sender, *args, **kwargs):
    print(sender)
# 自定义信号中注册函数
xxxxx.connect(func)
@app.route("/x")
def index():
    # 触发信号
    xxxxx.send('123123', k1='v1')
    return 'Index' 
 
if __name__ == '__main__':
    app.run()

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)

flask-script

用于实现类似于django中 python3 manage.py runserver ...类似的命令

安装:pip3 install flask-script

from flask_script import Manager
app = Flask(__name__)
manager=Manager(app)
...
if __name__ == '__main__':
    manager.run()
#以后在执行,直接:python3 manage.py runserver
#python3 manage.py runserver --help

自定制命令

@manager.command
def custom(arg):
    """
    自定义命令
    python manage.py custom 123
    :param arg:
    :return:
    """
    print(arg)


@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: python manage.py  cmd -n lqz -u http://www.oldboyedu.com
    执行: python manage.py  cmd --name lqz --url http://www.oldboyedu.com
    :param name:
    :param url:
    :return:
    """
    print(name, url)
#有什么用?
#把excel的数据导入数据库,定制个命令,去执行
原文地址:https://www.cnblogs.com/KrisYzy/p/11857899.html