def append(self, other):
        name = self.name
        to_concat = [self]

        if isinstance(other, (list, tuple)):
            to_concat = to_concat + list(other)
        else:
            to_concat.append(other)

        for obj in to_concat:
            if isinstance(obj, Index) and obj.name != name:
                name = None
                break

        to_concat = self._ensure_compat_concat(to_concat)
        to_concat, factory = _process_concat_data(to_concat, name)

        return factory(to_concat)
Append a collection of Index options together
dataset/ETHPy150Open pydata/pandas/pandas/tseries/index.py/DatetimeIndex.append