Writes shape to pys file

        Format: <rows>\t<cols>\t<tabs>\n

def _shape2pys(self):
        """Writes shape to pys file

        Format: <rows>\t<cols>\t<tabs>\n

        """

        shape_line = u"\t".join(map(unicode, self.code_array.shape)) + u"\n"
        self.pys_file.write(shape_line)