How to pass a CLOB pramater to a PL/SQL procedure call in Python

Question

I need to call my PLSQL procedure test_proc (parameter1 int ,parameter2 clob, paramter3 blob) inside python code as below. if i execute below code , i am getting PLS-00306: wrong number of types of arguments in call to I think in python lv_xml_clob variable is taking as str. or third paramter is None or ' ' or Null these values are not accepting for Blob. How can i pass NUll to Blob pramater

import cx_Oracle

dbPool = cx_Oracle.SessionPool(db_user, db_password, db_name)

dbConnection = dbPool.acquire()

Cursor = dbConnection.cursor()

lv_xml_clob = 'my clob data'

Cursor.callproc("test_pkg.test_proc",[1,lv_xml_clob,''])

dbPool.release(dbConnection)



Error :  PLS-00306: wrong number of types of arguments in call to - test_proc