code: def to_numpy_(self, table_name: str="data") -> numpy.array:
          
          try:
              renderer = pytablewriter.NumpyTableWriter
              data = self._build_export(renderer, table_name)
              return data
          except Exception as e:
              self.err(e, "Can not convert data to numpy array")
docs: Convert the main dataframe to a numpy array
  
          :param table_name: name of the python variable, defaults to "data"
          :param table_name: str, optional
          :return: a numpy array
          :rtype: np.array
  
          :example: ``ds.to_numpy_("myvar")``