文件夹结构

python-webapp/ <-- 根目录|+- UserConn/

     <-- Web目录，存放.py文件|  ||  +- static/           

     <-- 存放静态文件|  ||  +- templates/ 

     <--db.py

     <--main.py

Now we must the first to design the db.py

下面是实现数据库的链接类：

import pymysql

conn=pymysql.connect("localhost","root","********","test")

cur=conn.cursor()

def insert(username,password):

sql="insert into user (username,password) values ('%s','%s')"%(username,password)

cur.execute(sql)

conn.commit()

conn.close()

def isExisted(username,password):

sql="select*from user where username ='%s' and password ='%s'"%(username,password)

cur.execute(sql)

result=cur.fetchall()

if(len(result)==0):

return False

else:

return True

接下来是实现main模块的组件功能

from flask import Flask
from flask import request
from flask import render_template
from flask import redirect
from db import *
app=Flask(__name__)

from wtforms import Form,TextField,PasswordField,validators

//定义的LoginForm类
class LoginForm(Form):
    username = TextField("username",[validators.Required()])
    password = PasswordField("password",[validators.Required()])


//对http://127.0.0.1:8080/register的注册
@app.route("/register",methods=['GET','POST'])
def register():

    myForm=LoginForm(request.form)       //这里是对LoginForm的实例化

    if request.method=='POST':
        insert(myForm.username.data,myForm.password.data)   //insert方法对应的是db.py里面的insert(user，password)方法
        return render_template("Welcome.html")
    return render_template("login.html", form=myForm)


//对http://127.0.0.1:8080/login的注册
@app.route("/login",methods=['GET','POST'])
def login():
    myForm=LoginForm(request.form)
    if request.method =='POST':
        if (isExisted(myForm.username.data,myForm.password.data)):
            return redirect("http://Waynicshine.github.io")
        else:
            return "Login Failed"
    return render_template("login.html", form=myForm)

if __name__=="__main__":
    app.run(port=8080,debug=True)

index.html的前端表现


<html>
<head></head>
<body>
    <div align="center">
    <h1>User Management</h1>
    {% if message %} {{message}} {% endif %}
    <form method="post">
        Username :{{form.username}}
        <br/>
        Password :{{form.password}}
        <br/>
        <input type="submit" value="Submit" />
        <input type="reset" value="reset" /> 
    </form>
</div>
</body>
</html>