def __sub__(self, other):
        if isinstance(other, Label):
            if other.hemi == 'lh':
                lh = self.lh - other
                rh = self.rh
            else:
                rh = self.rh - other
                lh = self.lh
        elif isinstance(other, BiHemiLabel):
            lh = self.lh - other.lh
            rh = self.rh - other.rh
        else:
            raise TypeError("Need: Label or BiHemiLabel. Got: %r" - other)

        if len(lh.vertices) == 0:
            return rh
        elif len(rh.vertices) == 0:
            return lh
        else:
            name = '%s - %s' % (self.name, other.name)
            return BiHemiLabel(lh, rh, name, self.color)
dataset/ETHPy150Open mne-tools/mne-python/mne/label.py/BiHemiLabel.__sub__/operator `%` -> `-`