wtforms基本使用

WTForms是一个支持多个web框架的form组件，主要用于对用户请求数据进行验证。

1.安装

pip install wtforms

2.登录实例

用户登录

当用户登录时候，需要对用户提交的用户名和密码进行多种格式校验。如：

用户不能为空；用户长度必须大于6；

密码不能为空；密码长度必须大于12；密码必须包含字母、数字、特殊字符等（自定义正则）；

#!/usr/bin/env python
# -*- coding:utf-8 -*-
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 LoginForm(Form):
 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(),       设置input类型
 render_kw={'class': 'form-control'}  #添加多个属性

)
 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-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()

前端页面

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1>登录</h1>
<form method="post">
    <!--<input type="text" name="name">-->
    <p>{{form.name.label}} {{form.name}} {{form.name.errors[0] }}</p>

    <!--<input type="password" name="pwd">-->
    <p>{{form.pwd.label}} {{form.pwd}} {{form.pwd.errors[0] }}</p>
    <input type="submit" value="提交">
</form>
</body>
</html>

3.用户注册案例

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, '男'),
            (2, '女'),
        ),
        coerce=int
    )
    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': 1})
        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()

前端页面

<!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 item in form %}
    <p>{{item.label}}: {{item}} {{item.errors[0] }}</p>
    {% endfor %}
    <input type="submit" value="提交">
</form>
</body>
</html>

4.使用数据库中的选项

helper.py

import pymysql
from DBUtils.PooledDB import PooledDB, SharedDBConnection
import 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='db1',
 charset='utf8'
 )

def connect(type):
 conn = POOL.connection()
 cursor = conn.cursor(cursor=type)
 return conn,cursor


def connect_close(conn,cursor):
 cursor.close()
 conn.close()

def fetch_all(sql,args,type=pymysql.cursors.DictCursor):
 conn,cursor = connect(type)

cursor.execute(sql, args)
 record_list = cursor.fetchall()
 connect_close(conn,cursor)

return record_list


def fetch_one(sql, args):
 conn, cursor = connect()
 cursor.execute(sql, args)
 result = cursor.fetchone()
 connect_close(conn, cursor)

return result


def insert(sql, args):
 conn, cursor = connect()
 row = cursor.execute(sql, args)
 conn.commit()
 connect_close(conn, cursor)
 return row
import helper
class UserForm(Form):
 city = core.SelectField(
 label='城市',
 choices=(),
 coerce=int
 )
 name = simple.StringField(label='姓名')

def __init__(self,*args,**kwargs):
    super(UserForm,self).__init__(*args,**kwargs)
    self.city.choices=helper.fetch_all('select id,name from tablename',[],type=None)

Flask

#Python #Flask

wtforms基本使用

http://www.jcwit.com/article/256/

作者

Carlos

发布于

2018年8月5日

许可协议

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