Add from __future__ import annotations

phono3py/conductivity/init_direct_solution.py

@@ -34,6 +34,8 @@
 # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 # POSSIBILITY OF SUCH DAMAGE.
 
+from __future__ import annotations
+
 import os
 import sys
 from collections.abc import Sequence

phono3py/conductivity/wigner_direct_solution.py

@@ -34,6 +34,8 @@
 # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 # POSSIBILITY OF SUCH DAMAGE.
 
+from __future__ import annotations
+
 import numpy as np
 from phonopy.physical_units import get_physical_units
 

phono3py/cui/phono3py_argparse.py

@@ -34,6 +34,8 @@
 # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 # POSSIBILITY OF SUCH DAMAGE.
 
+from __future__ import annotations
+
 import sys
 
 from phonopy.cui.phonopy_argparse import fix_deprecated_option_names