当我在MySQL中更改密码时，我可以通过旧密码登录，但我无法通过新密码登录

Question

当我使用html页面恢复我的密码时，我在MySQL中的密码发生了变化，但它没有反映在浏览器中的Flask页面上，即我只能通过旧密码登录而不是新密码。 我正在使用Flask MySQL创建一个登录系统。 但是当我重新启动run.py时，新密码开始工作。

run.py

from flask import Flask
from flask import render_template
from flask import request
from flask import redirect
from flask import url_for
from flask import session
from wtforms import Form
from wtforms import BooleanField
from wtforms import TextField
from wtforms import PasswordField
from wtforms.fields.html5 import EmailField
from wtforms import validators
from form import *
import string
import random
import hashlib
import smtplib

app=Flask(__name__)
app.secret_key='Secret Key'
app.config['TRAP_HTTP_EXCEPTIONS']=True

import MySQLdb as mdb

db=mdb.connect('localhost','root','','database')
cur=db.cursor()

with db:
    cur.execute('set global event_scheduler=on')

def id_generator(size=5, chars=string.ascii_uppercase + string.digits + string.ascii_lowercase):
    return ''.join(random.choice(chars) for _ in range(size))

def passwordsend(receiver,mess):
    sender = 'sender@gmail.com'
    receivers = []
    receivers.append(receiver)
    message = """From: %s
    To: %s
    Subject: SMTP e-mail test

    %s
    """ % (sender, ", ".join(receivers),mess)

    server = smtplib.SMTP("smtp.gmail.com", 587)
    server.ehlo()
    server.starttls()
    server.ehlo()
    server.login('#sender', '#password')
    server.sendmail(sender, receivers, message)
    server.close()
    print 'successfully sent the mail'

@app.route('/')
def hello():
    if 'username' in session:
        return redirect('/prof')
    form1=Signup(request.form)
    form2=Signin(request.form)
    return render_template('home.html',form1=form1,form2=form2)

@app.route('/sup',methods=['GET','POST'])
def sup():
    if 'username' in session:
        return redirect('/prof')
    form=Signup(request.form)
    if request.method=='POST' and form.validate():
        n=form.username.data
        r=form.reg.data
        e=form.email.data
        p=id_generator()
        p=n+p
        pg=hashlib.md5()
        pg.update(p)
        p=pg.hexdigest()
        ps=url_for('passw',passhash=p)
        ps="127.0.0.1:5000"+ps
        passwordsend(e,ps)
        with db:
            cur.execute('insert into login values("",%s,%s,%s,%s,now(),0)',(n,p,r,e))
            return redirect('/')    
    return render_template('sup.html',form=form)

@app.route('/sin',methods=['GET','POST'])
def sin():
    if 'username' in session:
        return redirect('/prof')
    form=Signin(request.form)
    if request.method=='POST' and form.validate():
        session['username']=form.username.data
        return redirect('/prof')    
    return render_template('sin.html',form=form)        

@app.route('/prof')
def prof():
    if 'username' in session:
        with db:
            cur.execute('select username from login where username=%s',(session['username'],))
            ld=cur.fetchall()
        return render_template('prof1.html',users=ld[0][0])
    return render_template('prof.html')

@app.route('/logout')
def logout():
    if 'username' in session:
        session.pop('username',None)
        return redirect('/')
    return redirect('/sin')

@app.route('/passw/<passhash>',methods=['GET','POST'])
def passw(passhash):
    form=passchange(request.form)
    with db:
        cur.execute('select pass from login where pass=%s',(passhash,))
        ld1=cur.fetchall()
        if ld1:
            if request.method=='POST' and form.validate():
                with db:
                    cur.execute('select username from login where pass=%s',(passhash,))
                    ld=cur.fetchall()
                    n=ld[0][0]
                p=form.password.data
                p=n+p
                pg=hashlib.md5()
                pg.update(p)
                p=pg.hexdigest()
                with db:
                    cur.execute('update login set pass=%s where pass=%s',(p,passhash))
                    cur.execute('update login set activ=1 where pass=%s',(p,))
                    return redirect('/sin')
            return render_template('passchange.html',form=form,passhash=passhash)
        return render_template('passchangeerr.html')

@app.route('/fpass',methods=['GET','POST'])
def fpass():
    if 'username' in session:
        return redirect('/prof')
    form=fpassw(request.form)
    if request.method=='POST' and form.validate():
        with db:
            cur.execute('select pass from login where email=%s',(form.email.data,))
            ld=cur.fetchall()
            p=ld[0][0]
        e=form.email.data   
        ps=url_for('passw',passhash=p)
        ps="127.0.0.1:5000"+ps
        passwordsend(e,ps)
        return redirect('/')
    return render_template('fpass.html',form=form)

if __name__=='__main__':
    app.run(debug=True)

form.py

from run import *

def present(a):
    def _present(form, field):
        sql='select '+a+' from login where '+a+' =%s'
        cur.execute(sql,(field.data,))
        ld=cur.fetchall()
        if ld:
            raise validators.ValidationError(a+' already used')
    return _present

def absent(a,message="Error"):
    def _absent(form, field):
        sql='select '+a+' from login where '+a+' =%s'
        cur.execute(sql,(field.data,))
        ld=cur.fetchall()
        if ld:
            pass
        else:   
            raise validators.ValidationError(message)
    return _absent

def absentp(a,message="Error"):
    def _absentp(form, field):
        sql='select pass from login where username=%s'
        cur.execute(sql,(form.username.data,))
        ld=cur.fetchall()
        fd=form.username.data+field.data
        fdp=hashlib.md5()
        fdp.update(fd)
        fd=fdp.hexdigest()
        if ld:
            if ld[0][0]==fd:
                pass
            else:       
                raise validators.ValidationError(message)   
        else:   
            raise validators.ValidationError(message)
    return _absentp 

class Signup(Form):
    username = TextField('Username', [
        validators.Required("Username can not be empty"),
        validators.Length(min=4, max=16, message="Username length should be between 4 to 16 characters"),
        validators.Regexp('[a-zA-Z0-9.]',message="Username can contain only Letters Numbers and Periods"),
        present('Username')
        ],)
    reg=TextField('Registration No.', [
        validators.Required("Registration No can not be empty"),
        validators.Length(min=8, max=9, message="Error"),
        present('Reg'),
        validators.Regexp('^[0-9]{2}[A-Z]{3}[0-9]{3,4}$',message="Error")
        ],)
    email=EmailField('Email', [
    validators.Required("Email can not be empty"),
    validators.Length(min=8, max=50, message=None),
    validators.Regexp('[a-zA-Z0-9.]+@vit\.ac\.in|a\.99\.v\.99@gmail\.com',message="Use Your Official VIT Email ID"),
    present('Email')
    ],)

class Signin(Form):  
    username = TextField('', [
        validators.Length(min=4, max=16, message="Invalid Username or Password"),
        absent('Username',message="Invalid Username or Password")
        ],)
    password = PasswordField('', [
        validators.Required(message="Invalid Username or Password"),
        absentp('Pass',message="Invalid Username or Password")
        ],)

class passchange(Form):
    password = PasswordField('Password', [validators.Required(),validators.Length(min=6, max=20, message=None),validators.EqualTo('repass', message='Passwords must match')],)
    repass=PasswordField('ReEnter Password', [validators.Required()])

class fpassw(Form):
    email=EmailField('Email', [
    absent('Email',message="Err")
    ],)