python Flask

本章内容

flask入门

　　先贴个学习的文档，flask只是python其中的一部分，但是单单一个flask就不那么简单。

　　http://docs.jinkan.org/docs/flask/

　　先来个简单的小练习：

　　a.txt 文件中有python:123  java:456 文件，然后使之在浏览器中显示

from flask import Flask
app = Flask(__name__)

@app.route('/user')
def user():
    temp = '<tr><td>%s</td><td>%s</td></tr>'
    res = '<table border="1">'
    res += '<tr><td>USER</td><td>PASSWD</td></tr>'
    with open('a.txt') as f:
        for line in f:
            user = line.split(':')[0]  #把一行的文件已冒号为分割，然后取出
            passw = line.split(':')[1]
            res += temp%(user,passw)
    res += '</table>'
    return res
if __name__ == '__main__':
    app.run(host='0.0.0.0',port=9911,debug=True)

运行结果如下：

USER	PASSWD
python	123
java	456

 　　厉害了我的哥，看学来的简便的方法。

            user = line.split(':')[0]  #把一行的文件已冒号为分割，然后取出
            passw = line.split(':')[1]
            res += temp%(user,passw)

缩减为一行了：res += tmp%tuple(line.split(':'))
小知识点：　　

   with open('a.txt') as f:
        for line in f:
            print line.split(':')        #被split后就变成了一个list了。初始的line是string,python：123
            userlist.append(line.split(':'))
            print userlist

　　先鲁代码吧，课堂上的练习

from flask import Flask,render_template,request,redirect,session
app = Flask(__name__)
app.secret_key='abcdefghigklmnopgistuvwxyz'

@app.route('/login',methods=['GET','POST'])
def login():
    if request.method == 'GET':
        return render_template('login.html')
    elif request.method == 'POST':
        user = request.form.get('username')
        pwd = request.form.get('pwd')
        if user and pwd:
            if user == 'admin' and pwd == 'admin':
                session['user'] = 'admin'
                return redirect('/userlist')
            else:
                return 'wrong username or passwd!try again'
        else:
            return 'you need input your username or passwd'

@app.route('/logout')
def logout():
    del session['user']
    return redirect('/login')

@app.route('/userlist')
def userlist():
    userlist = []
    with open('a.txt') as f:
        for line in f:
            userlist.append(line.split(':'))
        return render_template('userlist.html',userxxx=userlist)

@app.route('/adduser',methods = ['GET','POST'])
def adduser():
    print session.get('user')
    print '*'*50
    if session.get('user') != 'admin':
        return 'you need login or not allowed this user'
    if request.method == 'GET':
        return render_template('adduser.html')
    elif request.method =='POST':
        user = request.form.get('user')
        pwd = request.form.get('pwd')
        with open('a.txt','a') as f:
            f.write(user+':'+pwd+'
')
        return redirect('/userlist')

if __name__ == '__main__':
    app.run(host='0.0.0.0',port=7777,debug=True)

 　　login简化版写法

#flask代码
@app.route('/login',methods=['GET','POST'])
def login():
    if request.method == 'POST':
        user_info = { k:v[0] for k,v in dict(request.form).items()}      #转化为字典的形式，格式看下面print
        print 'request.form',request.form
        print 'user_info',user_info
        res = getone('user',field,user_info)
        if res['code'] == 0:
            if res['msg']['password'] == user_info['password']:
                session['username'] = user_info['username']
                session['role'] = res['msg']['role']
                return json.dumps(res)
            else:
                res['code'] = 1 
                res['errmsg'] = 'user is exsit,but password is wrong'
                return json.dumps(res)
        else:
            res['errmsg'] = 'user is not exist!'
            return json.dumps(res)
    return render_template('login.html')

#代码解析
request.form ImmutableMultiDict([('username', u'pc'), ('password', u'12345')])         #转换前
user_info {'username': u'pc', 'password': u'12345'}                                    #转换后

#操作数据库，验证登录用户的信息
def getone(table,field,data):
    if data.has_key("username"):
         sql = 'select * from %s where username="%s"' % (table,data['username'])
    else:
         sql = 'select * from %s where id="%s"' % (table,data['id'])
    cur.execute(sql)
    res = cur.fetchone()
    print 'sql,sql_res',sql,res               #print结果详见下面
    if res:
       user = {k:res[i] for i,k in enumerate(field)}
       print 'user:',user                     #print结果详见下面
       result = {'code':0,'msg':user}
    else:
       result = {'code':1,'msg':"data is null"}
    return result

#运行结果：
sql,sql_res select * from user where username="pc" (7L, u'pc', u'1234567', 1L)
user: {'username': u'pc', 'password': u'1234567', 'role': 1L, 'id': 7L}

　　login.html代码，主部分主要是通过jinjia2和ajax去完成了，抛开了默认提交的功能

<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title> 登录 | TXadmin</title>
    <link rel="shortcut icon" href="/static/img/facio.ico" type="image/x-icon">
    <link href="/static/css/bootstrap.min.css" rel="stylesheet">
    <link href="/static/css/style.css" rel="stylesheet">
    <link href="/static/css/sweetalert.css" rel="stylesheet">
</head>

<body class="gray-bg">
    <div class="middle-box text-center loginscreen  animated fadeInDown">
        <div>
            <div>
                <h1 class="logo-name"><img src="/static/img/1.png"></h1>
            </div>
            
            <h2>Welcome to TXadmin</h2>
            <form id="loginForm" method="post">
                <div class="form-group">
                    <input id="name" type="text" name="username" class="form-control" placeholder="Username" required="length[6~50]">
                </div>
                <div class="form-group">
                    <input id="password" type="password" name="password" class="form-control" placeholder="Password" required="">
                </div>
                <button id="loginbtn" type="submit" class="btn btn-primary block full-width m-b">登录</button>
            </form>
            <p style="color:blue">管理员账号：pc, 密码：1234567</p>
            <p class="m-t"> <small><b>Copyright</b> Mr.python © 2017-2018</small> </p>
        </div> 
    </div>

    <!-- Mainly scripts -->
    <script src="/static/js/jquery-2.1.1.js"></script>
    <script src="/static/js/sweetalert.min.js"></script>        
    <script src="/static/js/bootstrap.min.js"></script>


    <script>
        $('#loginbtn').on('click',function(){
            var user_info = $('#loginForm').serialize()
            console.log(user_info)
            $.post('/login',user_info,function(data){
                console.log(data)
                data = JSON.parse(data)
                console.log(data)
                if (data['code']==0){
                     swal({ 
                        title: "登录成功", 
                        text: data['result'],   
                         type: "success",   
                        confirmButtonText: "确定" },function(){               
                  location.href="/"
                 }); 
                }else{
                    swal("MY GOD",data['errmsg'],"error");
                    }
            })
            return false          #作用是不在走默认的表单操作了
        })
    </script>

</body>

</html>

Flask + Mysql

连接数据库的5个步骤

    conn = MySQLdb.connect(host=DB_HOST, port=DB_PORT, user=DB_USER, passwd=DB_PASSWD, db=DB_DBNAME, charset=DB_CHARSET)
    cur = conn.cursor()
    cur.execute(SQL_USER_UPDATE, (clazz, tel, addr, age, uid))
    conn.commit()
    cur.close()
    conn.close()


   con.autocommit(True) #可以添加这一行，自动提交修改的内容到数据库

  

request.form.get   #获取post请求提交的参数
request.args.get   #获取get请求提交的参数