

def _validate_index_level(self, level):
    '\n        Validate index level.\n\n        For single-level Index getting level number is a no-op, but some\n        verification must be done like in MultiIndex.\n\n        '
    if isinstance(level, int):
        if ((level < 0) and (level != (- 1))):
            raise IndexError(('Too many levels: Index has only 1 level, %d is not a valid level number' % (level,)))
        elif (level > 0):
            raise IndexError(('Too many levels: Index has only 1 level, not %d' % (level + 1)))
    elif (level != self.name):
        raise KeyError(('Level %s must be same as name (%s)' % (level, self.name)))

dataset/ETHPy150Open pydata/pandas/pandas/indexes/base.py Index._validate_index_level/original