def saveKey(self, i):
        'convert to string key'
        if isinstance(i, int):
            return 'int:%s' % i
        elif isinstance(i, str):
            return i
        try:
            return 'int:%s' % int(i)
        except TypeError:
            pass
        raise KeyError('IntShelve can only save int or str as key')
dataset/ETHPy150Open cjlee112/pygr/pygr/mapping.py/IntShelve.saveKey/original