ValueError：验证密码时不是有效的sha256_crypt哈希，但未在mysql数据库中加密

Question

我找不到这段代码发生了什么错误。帮助我找出解决方案。Error Message为什么sha256_crypt.verify（password，possw_data）输入错误？我找不到解决方法。

from flask import Flask, render_template, request, redirect, url_for, session, flash
import MySQLdb
from passlib.hash import sha256_crypt

@app.route("/login", methods=["GET","POST"])
def login():
  if request.method == "POST":
     username = request.form["username"]
    password = sha256_crypt.encrypt(request.form['password'])
    cursor = mydb.cursor(MySQLdb.cursors.DictCursor)
    cursor.execute("SELECT username FROM user WHERE username ='"+ username +"'")
    userdata = cursor.fetchone()

    if userdata is None:
        flash("Incorrect username","danger")
        return render_template("login.html")
    else:
        for possw_data in userdata:
            if sha256_crypt.verify(password,possw_data):
                flash("You are now login","success")
                return redirect(url_for('profile'))
            else:
                flash("Incorrect password!")
                return render_template("login.html")

  return render_template("login.html")