[cx-oracle-users] Choosing client libraries

[<pw...@re...>]

Is there any way to control which client libraries will be used by cx_Oracle?

If the 8.1 client is used, then it cannot connect to XE or 10g.
If the XE client is used, then it cannot connect to 8.1.7.

When it fails, how can I give the user helpful information from which the problem might be resolved?  Yes, I can handle an exception.  What information should I give the user?

C:\src\python\db\cx_Oracle>test1.py
apilevel = 2.0
buildtime = January 26, 2005 14:37:48
version = HEAD
type =  <type 'str'>
dsn =  (DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=172.168.80.80)(PORT=1521)))(CONNECT_DATA=(SID=TRAIN)))
Traceback (most recent call last):
  File "C:\src\python\db\cx_Oracle\test1.py", line 15, in ?
    connection = cx_Oracle.connect("pwatson", "***********", "TRAIN")
cx_Oracle.DatabaseError: ORA-12154: TNS:could not resolve the connect identifier specified