packages/vaex-core/vaex/dataframe.py
def length(self, selection=False):
        """Get the length of the DataFrames, for the selection of the whole DataFrame.

        If selection is False, it returns len(df).

        TODO: Implement this in DataFrameRemote, and move the method up in :func:`DataFrame.length`

        :param selection: When True, will return the number of selected rows
        :return:
        """
        if selection:
            return 0 if self.mask is None else np.sum(self.mask)
        else:
            return len(self)
def length(self, selection=False):
        """Get the length of the DataFrames, for the selection of the whole DataFrame.

        If selection is False, it returns len(df).

        TODO: Implement this in DataFrameRemote, and move the method up in :func:`DataFrame.length`

        :param selection: When True, will return the number of selected rows
        :return:
        """
        if selection:
            return 0 if self.mask is None else np.sum(self.mask)
        else:
            return len(self)
Get the length of the DataFrames, for the selection of the whole DataFrame.

        If selection is False, it returns len(df).

        TODO: Implement this in DataFrameRemote, and move the method up in :func:`DataFrame.length`

        :param selection: When True, will return the number of selected rows
        :return: