一、什么是wtforms
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：
pip3 install WTForms
二、简单使用wtforms组件
（一）用户登陆验证
py文件代码：
from flask import Flask,render_template,request,redirect
from wtforms.fields import core
from wtforms.fields import html5
from wtforms.fields import simple
from wtforms import Form
from wtforms import validators
from wtforms import widgets
app = Flask(__name__,template_folder="templates") class Myvalidators(object):
'''自定义验证规则'''
def __init__(self,message):
self.message = message
def __call__(self, form, field):
print(field.data,"用户输入的信息")
if field.data == "haiyan":
return None
raise validators.ValidationError(self.message) class LoginForm(Form):
'''Form'''
name = simple.StringField(
label="用户名",
widget=widgets.TextInput(),
validators=[
Myvalidators(message="用户名必须是haiyan"),#也可以自定义正则
validators.DataRequired(message="用户名不能为空"),
validators.Length(max=8,min=3,message="用户名长度必须大于%(max)d且小于%(min)d")
],
render_kw={"class":"form-control"} #设置属性
) pwd = simple.PasswordField(
label="密码",
validators=[
validators.DataRequired(message="密码不能为空"),
validators.Length(max=8,min=3,message="密码长度必须大于%(max)d且小于%(min)d"),
validators.Regexp(regex="\d+",message="密码必须是数字"),
],
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("用户提交的数据用过格式验证，值为：%s"%form.data)
return "登录成功"
else:
print(form.errors,"错误信息")
return render_template("login.html",form=form) if __name__ == '__main__':
app.run(debug=True)
login.html：
<body>
<form action="" method="post" novalidate>
<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">
<!--用户名：<input type="text">-->
<!--密码：<input type="password">-->
<!--<input type="submit" value="提交">-->
</form>
</body>
前端页面效果：
（二）用户注册验证
py文件代码：
from flask import Flask,render_template,redirect,request
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 =======================simple===========================
class RegisterForm(Form):
name = simple.StringField(
label="用户名",
validators=[
validators.DataRequired()
],
widget=widgets.TextInput(),
render_kw={"class":"form-control"},
default="haiyan"
)
pwd = simple.PasswordField(
label="密码",
validators=[
validators.DataRequired(message="密码不能为空")
]
)
pwd_confim = simple.PasswordField(
label="重复密码",
validators=[
validators.DataRequired(message='重复密码不能为空.'),
validators.EqualTo('pwd',message="两次密码不一致")
],
widget=widgets.PasswordInput(),
render_kw={'class': 'form-control'}
) ========================html5============================
email = html5.EmailField( #注意这里用的是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'}
) ===================以下是用core来调用的=======================
gender = core.RadioField(
label="性别",
choices=(
(1,"男"),
(1,"女"),
),
coerce=int #限制是int类型的
)
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): #这里的self是一个RegisterForm对象
'''重写__init__方法'''
super(RegisterForm,self).__init__(*args, **kwargs) #继承父类的init方法
self.favor.choices =((1, '篮球'), (2, '足球'), (3, '羽毛球')) #吧RegisterForm这个类里面的favor重新赋值 def validate_pwd_confim(self,field,):
'''
自定义pwd_config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}) #默认是1,
return render_template("register.html",form=form)
else:
form = RegisterForm(formdata=request.form)
if form.validate(): #判断是否验证成功
print('用户提交数据通过格式验证，提交的值为：', form.data) #所有的正确信息
else:
print(form.errors) #所有的错误信息
return render_template('register.html', form=form) if __name__ == '__main__':
app.run()
register.html：
<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>
前端页面效果：