Failing to connect using sl_storage = object_storage.get_client('YOUR_USERNAME', 'YOUR_API_KEY', datacenter='dal05')

Don't know which credentials to use. Here is what my Bluemix OS credentials looks like

{
  "auth_url": "https://identity.open.softlayer.com",
  "project": "object_storage_072d5151_ee1a_4432_afa8_e822cbaa146c",
  "projectId": "1af89xxxxx1853",
  "region": "dallas",
  "userId": "fdcd47xxxxx9a60b3ac5",
  "username": "member_aa460xxxxxxx0d5b70",
  "password": "*******",
  "domainId": "c4exxxxxxx1338",
  "domainName": "10xxxx61",
  "role": "member"
}

I tried the userIdand username as YOUR_USERNAME and password as YOUR_API_KEY. And always got AuthenticationError: Invalid Credentials

Anything I am doing wrong here or any code must be updated???