(self)
display some data trace (not implemented)
display some data trace (not implemented)
display some data trace ( not implemented )
def disp(self):
        """display some data trace (not implemented)"""
        print('method BaseDataLogger.disp() not implemented, to be done in subclass ' + str(type(self)))
def disp ( self ) : print ( 'method BaseDataLogger.disp() not implemented, to be done in subclass ' + str ( type ( self ) ) )