简介
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
用户登录注册示例
1. 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）；
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(),
render_kw={'class': 'form-control'}
)
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()
<!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>
2. 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):
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)
<!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>
通过以上示例，我们可以快速学会简单实用WTForms组件。