Flask组件之wtforms(一)
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。
安装wtforms:
pip3 install wtforms
登陆简单示例
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 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', # 中文名称 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') ], # 验证方式 widget=widgets.TextInput(), # 页面展示插件 render_kw={'class': 'form-control'} # 自定义属性--定制样式 ) 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-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': # 实例化Form对象 form = LoginForm() # form传到前端 return render_template('login.html', form=form) else: # formdata=request.form 获取data form = LoginForm(formdata=request.form) # form.validate() 验证data if form.validate(): # form.data 验证成功后的值 ''' form.data === {'name': 'adminss', 'pwd': 'Aa1!1234'} ''' data = form.data print('用户提交数据通过格式验证,提交的值为:', data) print(data['name']) print(data['pwd']) else: # form.errors 错误信息 ''' form.errors === {'name': ['用户名长度必须大于6且小于18'], 'pwd': ['用户名长度必须大于8', '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']} ''' print('错误信息',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"> <!--<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>
用户注册
注册页面需要让用户输入:用户名、密码、密码重复、性别、爱好等。

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): # String name = simple.StringField( label='用户名', # 中文名 validators=[ validators.DataRequired() ], # 验证方式 widget=widgets.TextInput(), # 展示插件 render_kw={'class': 'form-control'}, # 自定义属性 default='alex' # 默认值 ) pwd = simple.PasswordField( label='密码', validators=[ validators.DataRequired(message='密码不能为空.') ], widget=widgets.PasswordInput(), render_kw={'class': 'form-control'} ) # Password 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") ], # validators.DataRequired 验证是否为空 # validators.EqualTo 验证是否跟什么字段要一样 widget=widgets.PasswordInput(), render_kw={'class': 'form-control'} ) # Email 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'), # widgets.TextInput(input_type='email') == <input type='email' /> render_kw={'class': 'form-control'} ) # Radio gender = core.RadioField( label='性别', choices=( (1, '男'), (2, '女'), ), coerce=int # coerce=int 将用户提交的1,2 == str() ) # Select city = core.SelectField( label='城市', choices=( ('bj', '北京'), ('sh', '上海'), ) ) # SelectMultiple hobby = core.SelectMultipleField( label='爱好', choices=( (1, '篮球'), (2, '足球'), ), coerce=int ) # Checkbox 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')) # 重写__init__来实现实时更新数据--数据库取值 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,'hobby':[1,2]}) # 'gender': 1 默认值 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 item in form %} <p>{{item.label}}: {{item}} {{item.errors[0] }}</p> {% endfor %} <input type="submit" value="提交"> </form> </body> </html>