How to use the pyexcelerate.Format.Format function in PyExcelerate

def format(self):
        # don't use default because default should be const
        return Utility.lazy_get(self, '_format', Format.Format())

def __or__(self, other):
        return Format(
            format=Utility.nonboolean_or(self.format, other.format, None))

def set_cell_value(self, x, y, value):
        if DataTypes.get_type(value) == DataTypes.DATE:
            self.get_cell_style(x, y).format = Format.Format('yyyy-mm-dd')
        if x < len(self._dense_cells) and y < len(self._dense_cells[x]):
            self._dense_cells[x][y] = value
        else:
            self._sparse_cells[x][y] = value
        self._columns = max(self._columns, y)

def __xor__(self, other):
        return Format(
            format=Utility.nonboolean_xor(self.format, other.format, None))

def __and__(self, other):
        return Format(
            format=Utility.nonboolean_and(self.format, other.format, None))

def is_default(self):
        return self == Format()