sqlalchemy and Unicode strings: errormessage

[Wolfgang Meiners]

Hi,

I am trying to build an application using sqlalchemy.

in principle i have the structure

#==============================================

from sqlalchemy import *
from sqlalchemy.orm import *

metadata = MetaData('sqlite://')
a_table = Table('tf_lehrer', metadata,
    Column('id', Integer, primary_key=True),
    Column('Kuerzel', Text),
    Column('Name', Text))

A_class = Class(object):
    def __init__(self, Kuerzel, Name)
        self.Kuerzel=Kuerzel
        self.Name=Name

mapper(A_class, a_table)

A_record = A_class('BUM', 'Bäumer')

Session = sessionmaker()
session = Session()

session.add(A_record)

session.flush()

#================================================

At this time it runs to the line

session.flush()

where i get the following errormessage:

sqlalchemy.exc.ProgrammingError: (ProgrammingError) You must not use
8-bit bytestrings unless you use a text_factory that can interpret 8-bit
bytestrings (like text_factory = str). It is highly recommended that you
instead just switch your application to Unicode strings. u'INSERT INTO
tf_lehrer ("Kuerzel", "Name") VALUES (?, ?)' ('BUM', 'B\xc3\xa4umer')

but where can i switch my  application to Unicode strings?

Thank you for all hints
Wolfgang