def _maybe_cast_indexer(self, key):

        if is_float(key) and not self.is_floating():
            try:
                ckey = int(key)
                if ckey == key:
                    key = ckey
            except (ValueError, TypeError):
                pass
        return key
If we have a float key and are not a floating index
dataset/ETHPy150Open pydata/pandas/pandas/indexes/base.py/Index._maybe_cast_indexer