class Size:

    """Size class.

    Implements attribute access (.w, .h) and list-like access([0],[1]).

    """

    def __init__(self, *args, **kwargs):

        self.w = 0

        self.h = 0

        self.update(*args, **kwargs)

    def __getitem__(self, key):

        return (self.w, self.h)[key]

    def __repr__(self):

        return 'Size(w={0.w},h={0.h})'.format(self)

    def update(self, *args, **kwargs):

        if len(args) == 2:

            # (w:int, h:int)

            self.w, self.h = args

        elif len(args) == 1:

            # (size:Size)

            self.w, self.h = args[0]

        elif len(args):

            raise ValueError('Too many args.')

        for key, val in kwargs.items():

            if key in ('w', 'h'):

                setattr(self, key, val)

            else:

                raise ValueError('Bad keyword arg: %r' % key)

    def readonly(self):

        return ReadonlySize(self)

class ReadonlySize:

    """Wrapper for Size which makes it read-only."""

    def __init__(self, size):

        self._size = size

    @property

    def w(self):

        return self._size.w

    @property

    def h(self):

        return self._size.h

    def __getitem__(self, key):

        return self._size[key]

    def __repr__(self):

        return 'ReadonlySize(w={0.w},h={0.h})'.format(self._size)