Method _reduce

pandas/core/arrays/period.py:1153–1159

(
        self, name: str, *, skipna: bool = True, keepdims: bool = False, **kwargs
    )

    # Reductions

    def _reduce(
        self, name: str, *, skipna: bool = True, keepdims: bool = False, **kwargs
    ):
        result = super()._reduce(name, skipna=skipna, keepdims=keepdims, **kwargs)
        if keepdims and isinstance(result, np.ndarray):
            return self._from_sequence(result, dtype=self.dtype)
        return result


def raise_on_incompatible(left, right) -> IncompatibleFrequency: