python - Select query fails in sqlalchemy -

please having issue first sqlachemy app. trying query db posgres , return row matches . below code.

app.py

from sqlalchemy.orm import sessionmaker models.models import base,user,product,productitem,database, initialize  engine = database base.metadata.bind = (engine)  dbsession = sessionmaker(bind=engine) session = dbsession()  ....   @app.route('/login', methods = ['get','post']) def login():     form = registerform.loginform()     if request.method == 'get':         return render_template('login.html', form=form)     return authenticate(form = form)  def authenticate(form):     if form.validate_on_submit():         try:             user = session.query(user).filter(user.email == 'xxxx@yahoo.com')             if session.query(exists().where(user.email == form.email.data)).scalar() :                 return user.name         except :# models.doesnotexist:             flash("your email or password not match !", "error")             return 'error' 

my modules in seperate folder modules

modules/modules.py

#declarations  base = declarative_base()  engine = create_engine('postgresql://postgres:0102443167@localhost:5432/postgres',echo=true) base.metadata.bind = (engine)  dbsession = sessionmaker(bind=engine) session = dbsession()  database = engine  class user(usermixin , base):     __tablename__ = 'users'     id = column(integer, primary_key=true)     title = column(char(3), nullable = false)     fname = column(string(100), nullable = false)     lname = column(string(100), nullable = false)     username = column(string(100), nullable = false, unique = true)     email = column (string(50), nullable =false, unique = true)     password = column(string(100), nullable = false)     address = column(string(250), nullable = false)     state = column(string(50), nullable = false)     is_admin = column(boolean ,default = false)     is_logged = column(boolean, default = false)     is_active = column (boolean , default = false)     is_block = column(boolean, default = false)     joined_on = column(arrowtype)      ...... 

my problem app.py authenticate method. code

user = session.query(user).filter(user.email == form.email.data) 

raise error. when check form.email.data return correct string. when tried

 if session.query(exists().where(user.email == form.email.data)).scalar() :          return 'ok' 

works expected. works perfect , make me realize issue might query . tried

if session.query(exists().where(user.email == form.email.data)).scalar() :        return user.lname 

and raise error saying user not have property name should have. confuse. please how query record tables ? appreciated

you have first object matches query have add .first() @ end of query:

user = session.query(user).filter(user.email == form.email.data).first() 

see here more info.