How to Get Partition Column Name of a Partitioned Table in Oracle

SQL> desc dba_part_key_columns

Name             Null?    Type
---------------- -------- ----------------------
OWNER                     VARCHAR2(30)
NAME                      VARCHAR2(30)
OBJECT_TYPE               CHAR(5)
COLUMN_NAME               VARCHAR2(4000)
COLUMN_POSITION           NUMBER

SQL> select OWNER, NAME, OBJECT_TYPE, COLUMN_NAME, COLUMN_POSITION 
     from   DBA_PART_KEY_COLUMNS 
     where  OWNER ='TESTUSER' 
     and    OBJECT_TYPE='TABLE';