def __init__(self, transform, init_dict=None, **kwargs):
        '''Create a new TransformDict with the given *transform* function.
        *init_dict* and *kwargs* are optional initializers, as in the
        dict constructor.
        '''
        if not callable(transform):
            msg = 'expected a callable, got %r'
            raise TypeError(transform.__class__ % msg)
        self._transform = transform
        # transformed => original
        self._original = {}
        self._data = {}
        if init_dict:
            self.update(init_dict)
        if kwargs:
            self.update(kwargs)
dataset/ETHPy150Open fluentpython/example-code/03-dict-set/transformdict.py/TransformDict.__init__/swapped operands of `%`