future annotations and TYPE_CHECKING

Author: fsoubelet

optics_functions/rdt.py

@@ -4,13 +4,14 @@
 
 Functions for the calculations of Resonance Driving Terms, as well as
 getting lists of valid driving term indices for certain orders.
-
 """
 
+from __future__ import annotations
+
 import itertools
 import logging
-from collections.abc import Sequence
 from math import factorial
+from typing import TYPE_CHECKING
 
 import numpy as np
 import pandas as pd
@@ -27,6 +28,9 @@
     timeit,
 )
 
+if TYPE_CHECKING:
+    from collections.abc import Sequence
+
 LOG = logging.getLogger(__name__)