@docsubst<EOL><INDENT>def to_items(self, column_names=None, selection=None, strings=True, virtual=False):<DEDENT>
items = []<EOL>for name in column_names or self.get_column_names(strings=strings, virtual=virtual):<EOL><INDENT>items.append((name, self.evaluate(name, selection=selection)))<EOL><DEDENT>return items<EOL>
Return a list of [(column_name, ndarray), ...)] pairs where the ndarray corresponds to the evaluated data

        :param column_names: list of column names, to export, when None DataFrame.get_column_names(strings=strings, virtual=virtual) is used
        :param selection: {selection}
        :param strings: argument passed to DataFrame.get_column_names when column_names is None
        :param virtual: argument passed to DataFrame.get_column_names when column_names is None
        :return: list of (name, ndarray) pairs