'datetime.datetime' object has no attribute 'total_seconds' code example

Example: 'datetime.datetime' object has no attribute 'total_seconds'

def timestamp(self):
    "Return POSIX timestamp as float"
    if self._tzinfo is None:
        s = self._mktime()
        return s + self.microsecond / 1e6
    else:
        return (self - _EPOCH).total_seconds()