import cx_Oracle
import Decimal

def convert_as_decimal(cursor, name, defaultType, size, precision, scale):
    if defaultType == cx_Oracle.NUMBER:
        return cursor.var(str, 100, cursor.arraysize, outconverter = decimal.Decimal)

class foo:
    def __init__(self, db, user, password):
        self.db = db
        self.user = user
        self.password = password

    def connect(self, convert_to_decimal=None):
        conn = cx_Oracle.connect(self.user, self.password, self.db)
        db.outputtypehandler = convert_as_decimal
        self.conn = conn

    def execute(self, sql):
        cur = self.conn.cursor()
        cur.execute(sql)
        return cur


sql = 'select * from example_table'

db_conn = foo('example_user', example_password, example_db)
cursor_a = db_conn.execute(sql)

for row in cursor_a:
    print row