WTForms

一、简单介绍flask中的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

用户登录简例：

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()    # 传递form
        return render_template("login.html",form=form)
    else:
        form = LoginForm(formdata=request.form)
        if form.validate():      # 校验
            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.__call__()
    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>

参考链接：https://www.cnblogs.com/haiyan123/p/8254228.html