I am trying to use pycharm(3.3) to access my Oracle SQL(11.2.0) using the below codes but getting error with below details.
I had an issue very similar to yours. I was able to solve it by using a different connection method:
my_dsn = cx_Oracle.makedsn("host",port,sid="sid")
connection = cx_Oracle.connect(user="user", password="password", dsn=my_dsn)
cursor = connection.cursor()
querystring = "SQL query"
cursor.execute(querystring)
See http://cx-oracle.readthedocs.io/en/latest/module.html for more information