How to set DateTime value to blank via Python SDK

How to set DateTime value to blank via Python SDK

I want to clear a previously set datetime custom opportunity field in Zoho CRM using python SDK 2.1 (3.0.0)

The following fails with a TYPE_ERROR:
  1. deal_record.add_key_value('myfield', None)

The following fails with "Invalid date format string (too short):
  1. deal_record.add_key_value('myfield', "")

There are no examples of clearing a datetime field in python example code.