title: logon denied for sys user when connecting from python to oracle
body: <p>I'm facing logon denied error when connecting to Oracle 11g using python 3.4. with oracle client library version 5.1.3. I have observed this issue only with user "sys as sysdba", but not with other user. I'm able to connect to Oracle with "sys as sysdba" from other DB clients. I have used below to code to connect.</p>
  
  <pre><code>dns = cx_Oracle.makedsn('xxxxxx','1521','db')
  con = cx_Oracle.connect('sys as sysdba', 'xxxxx', dns)
  </code></pre>
  
  <p>Please advice, what I'm doing wrong.</p>
  
  <p>thanks.</p>