Split a power/toughness string on the correct slash.

        Correctly accounts for curly braces to denote fractions.
        E.g., '2/2' --> ['2', '2']
        '3{1/2}/3{1/2}' --> ['3{1/2}', '3{1/2}']

def split_pow_tgh(self, text):
        """Split a power/toughness string on the correct slash.

        Correctly accounts for curly braces to denote fractions.
        E.g., '2/2' --> ['2', '2']
        '3{1/2}/3{1/2}' --> ['3{1/2}', '3{1/2}']

        """
        return [n for n in re.split(r"/(?=([^{}]*{[^{}]*})*[^{}]*$)", text)
                if n is not None][:2]