code: def _dt_to_epoch(self, dt):
          
          if PY2:
              # The input datetime is from botocore unmarshalling and it is
              # offset-aware so the timedelta of subtracting this time
              # to 01/01/1970 using the same tzinfo gives us
              # Unix Time (also known as POSIX Time).
              time_delta = dt - datetime(1970, 1, 1).replace(tzinfo=dt.tzinfo)
              return int(time_delta.total_seconds())
          else:
              # Added in python 3.3+ and directly returns POSIX time.
              return int(dt.timestamp())
docs: Convert a offset-aware datetime to POSIX time.