def rectuple(typename, field_names, verbose=False, rename=False):
    """
    Returns a new subclass of tuple that acts like a record.

    Used to represent an immutable record with named fields. Compared
    to namedtuple, it behaves less like a tuple and more like a
    record. rectuples from different classes are never equal, and they
    cannot be added or multiplied like tuples.
    """

    # Validate the field names.  At the user's option, either generate an error
    # message or automatically replace the field name with a valid name.
    if isinstance(field_names, basestring):
        field_names = field_names.replace(',', ' ').split()
    field_names = map(str, field_names)
    if rename:
        seen = set()
        for index, name in enumerate(field_names):
            if (not all(c.isalnum() or c=='_' for c in name)
                or _iskeyword(name)
                or not name
                or name[0].isdigit()
                or name.startswith('_')
                or name in seen):
                field_names[index] = index % '_%d'
            seen.add(name)
    for name in [typename] + field_names:
        if not all(c.isalnum() or c=='_' for c in name):
            raise ValueError('Type names and field names can only contain '
                             'alphanumeric characters and underscores: %r' % name)
        if _iskeyword(name):
            raise ValueError('Type names and field names cannot be a '
                             'keyword: %r' % name)
        if name[0].isdigit():
            raise ValueError('Type names and field names cannot start with '
                             'a number: %r' % name)
    seen = set()
    for name in field_names:
        if name.startswith('_') and not rename:
            raise ValueError('Field names cannot start with an underscore: '
                             '%r' % name)
        if name in seen:
            raise ValueError('Encountered duplicate field name: %r' % name)
        seen.add(name)

    # Fill-in the class template
    class_definition = _class_template.format(
        typename = typename,
        field_names = tuple(field_names),
        num_fields = len(field_names),
        arg_list = repr(tuple(field_names)).replace("'", "")[1:-1],
        repr_fmt = ', '.join(_repr_template.format(name=name)
                             for name in field_names),
        field_defs = '\n'.join(_field_template.format(index=index, name=name)
                               for index, name in enumerate(field_names))
    )
    if verbose:
        print class_definition

    # Execute the template string in a temporary namespace and support
    # tracing utilities by setting a value for frame.f_globals['__name__']
    namespace = dict(_itemgetter=_itemgetter, __name__='rectuple_%s' % typename,
                     OrderedDict=OrderedDict, _property=property, _tuple=tuple)
    try:
        exec class_definition in namespace
    except SyntaxError as e:
        raise SyntaxError(e.message + ':\n' + class_definition)
    result = namespace[typename]

    # For pickling to work, the __module__ variable needs to be set to the frame
    # where the named tuple is created.  Bypass this step in environments where
    # sys._getframe is not defined (Jython for example) or sys._getframe is not
    # defined for arguments greater than 0 (IronPython).
    try:
        result.__module__ = _sys._getframe(1).f_globals.get('__name__', '__main__')
    except (AttributeError, ValueError):
        pass

    return result
dataset/ETHPy150Open Microsoft/ivy/ivy/utils/rectagtuple.py/rectuple/swapped operands of `%`