From 2f7532d58f06d042dbe0f4399e93da38d3cb7511 Mon Sep 17 00:00:00 2001
From: Remco de Boer <29308176+redeboer@users.noreply.github.com>
Date: Wed, 20 Dec 2023 16:45:38 +0100
Subject: [PATCH] MAINT: put `TypeVar` definitions under `TYPE_CHECKING`

---
 src/ampform/sympy/_decorator.py | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/src/ampform/sympy/_decorator.py b/src/ampform/sympy/_decorator.py
index f23ce09ae..138ec3698 100644
--- a/src/ampform/sympy/_decorator.py
+++ b/src/ampform/sympy/_decorator.py
@@ -18,17 +18,23 @@
     from typing import Protocol, TypedDict
 
 if sys.version_info < (3, 11):
-    from typing_extensions import ParamSpec, Unpack, dataclass_transform
+    from typing_extensions import dataclass_transform
 else:
-    from typing import ParamSpec, Unpack, dataclass_transform
+    from typing import dataclass_transform
 
 if TYPE_CHECKING:
     from sympy.printing.latex import LatexPrinter
 
+    if sys.version_info < (3, 11):
+        from typing_extensions import ParamSpec, Unpack
+    else:
+        from typing import ParamSpec, Unpack
+
+    H = TypeVar("H", bound=Hashable)
+    P = ParamSpec("P")
+    T = TypeVar("T")
+
 ExprClass = TypeVar("ExprClass", bound=sp.Expr)
-P = ParamSpec("P")
-T = TypeVar("T")
-H = TypeVar("H", bound=Hashable)
 
 
 class SymPyAssumptions(TypedDict, total=False):