'Return the list of column indeces when given a list of column_names.
:param list_of_column_names: the names of the columns of which to get indeces.
:type list_of_column_names: list of strs
:raises KeyError: if column_names are not found
:raises ValueError: if an entry in list_of_column_names is not in column_names'

def get_indeces_by_column_names(self, list_of_column_names):

    metadata_column_names = (self.dataset.metadata.column_names or getattr(self.dataset.datatype, 'column_names', None) or None)
    if (not metadata_column_names):
        raise KeyError(('No    column_names    found    for    ' + ('datatype:    %s,    dataset:    %s' % (str(self.dataset.datatype), str(self.dataset)))))
    indeces = []
    for column_name in list_of_column_names:
        indeces.append(metadata_column_names.index(column_name))
    return indeces
