wtforms组件使用
1.1.安装
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。安装方法
pip install wtforms
1.2.用户登录
用户登录时，对用户名和密码进行验证
（1）app.py
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):
name = simple.StringField(
label='用户名',
#自定义的验证规则
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')
],
#页面显示的插件
widget=widgets.TextInput(),
#加属性
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'),
#正则表达式
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()
（2）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>
用户名和密码格式不对
1.3.用户注册
（1）app.py
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='derek'
) 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.'),
#EqualTo：要跟那个字段一样
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'}
) #RadiField单选
gender = core.RadioField(
label='性别',
choices=(
(1, '男'),
(2, '女'),
),
coerce=int #因为前段提交过来的数据都是str格式，比如“1”，“2”，这里转换成int
)
#单选的下拉框
city = core.SelectField(
label='城市',
choices=(
('bj', '北京'),
('sh', '上海'),
)
)
#多选的下拉框
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(), #多选
coerce=int,
default=[1, 2]
) def __init__(self, *args, **kwargs):
super(RegisterForm, self).__init__(*args, **kwargs)
#重写默认的方法
self.favor.choices = ((1, '篮球'), (2, '足球'), (3, '羽毛球')) #钩子函数
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':
#data={'gender': 1 } 传到前端页面显示的默认值，这里只设置了gender，其它字段也可以通过这种方式设置
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()
(2).register.html
可以直接循环取出所有字段
<!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>
注册页面显示：
