Transaction Error in Python

Question

Hello,
I am running Python 2.5 (stackless) on Windows XP with the default installation of BerkeleyDB (version 4.4.20). What might be relevant is that I installed version 4.7.1, but did not update anything in my Python directories, and I am not fully sure where the Python installation is looking to find its default 4.4.20 version of BerkeleyDB.
My problem is that I am having great difficulty trying to do a simple transaction. I am probably making a simple mistake, but I cannot determine why I might be getting this error. As a side note, I am not interested using locks at this time. Any help would be appreciated in figuring out what the error message means and how to avoid receiving this error in the future (as seen in the Python session below).
Thanks,
Allan
from bsddb import db
env_flags = db.DB_CREATE | db.DB_INIT_LOG | db.DB_INIT_MPOOL | db.DB_INIT_TXN
db_flags = db.DB_CREATE
env = db.DBEnv(0)
env.open('c:\\temp\\test', env_flags, 0)
mydb = db.DB(env, 0)
mydb.open(None, 'test123.db', db.DB_BTREE, db_flags, 0)
mydb.put('1','2')
mydb.get('1')'2'
txn = env.txn_begin()
txn<DBTxn object at 0x00A80278>
mydb.put('3', '4', txn, 0)Traceback (most recent call last):
File "<stdin>", line 1, in <module>
bsddb.db.DBInvalidArgError: (22, 'Invalid argument -- Transaction specified for a DB handle opened outside a transaction')
>>>

Answer 1

Thank you for the response, but I receive an error on the open command. According to the documentation, there is no transaction parameter for the opening of the database: open(filename, dbname=None, dbtype=DB_UNKNOWN, flags=0, mode=0660).
This would probably work:
from bsddb import db
env_flags = db.DB_CREATE | db.DB_INIT_LOG |db.DB_INIT_MPOOL | db.DB_INIT_TXN
db_flags = db.DB_CREATE
env = db.DBEnv(0)
env.open('c:\\temp\\test', env_flags, 0)
txn = env.txn_begin()
mydb = db.DB(env, 0)
mydb.open(txn, 'test123.db', db.DB_BTREE,db_flags, 0)
mydb.put('1','2')
mydb.get('1')
mydb.put('3', '4', txn, 0)