code: def delete_columns(self, columns):
          
          columns = [columns] if not isinstance(columns, (list, blist)) else columns
          if not all([x in self._columns for x in columns]):
              raise ValueError('all columns must be in current columns')
          for column in columns:
              c = self._columns.index(column)
              del self._data[c]
              del self._columns[c]
          if not len(self._data):  # if all the columns have been deleted, remove index
              self.index = list()
docs: Delete columns from the DataFrame
  
          :param columns: list of columns to delete
          :return: nothing