Returns a header as a list, ready to write to TSV file

def generate_header(headerfields, oldheader, group_by_field):
    """Returns a header as a list, ready to write to TSV file"""
    fieldtypes = ['peptidefdr', 'peptidepep', 'nopsms', 'proteindata',
                  'precursorquant', 'isoquant']
    return generate_general_header(headerfields, fieldtypes,
                                   peptabledata.HEADER_PEPTIDE, oldheader,
                                   group_by_field)