Only import from typing_extensions if TYPE_CHECKING (#52)

Author: timmens

src/dags/output.py

@@ -4,13 +4,13 @@
 import inspect
 from typing import TYPE_CHECKING, overload
 
-from typing_extensions import Unpack
-
 from dags.exceptions import DagsError
 
 if TYPE_CHECKING:
     from collections.abc import Callable
 
+    from typing_extensions import Unpack
+
     from dags.typing import MixedTupleType, P, T
 
 

src/dags/typing.py

@@ -1,15 +1,16 @@
 from __future__ import annotations
 
-from typing import ParamSpec, TypeVar
+from typing import TYPE_CHECKING, ParamSpec, TypeVar
 
-from typing_extensions import TypeVarTuple
+if TYPE_CHECKING:
+    from typing_extensions import TypeVarTuple
 
-# ParamSpec representing the full signature (positional and keyword parameters) of a
-# callable
-P = ParamSpec("P")
-# TypeVar representing the return type of a callable
-R = TypeVar("R")
-# Generic type variable for use in type constructors
-T = TypeVar("T")
-# Variadic TypeVar for tuples of arbitrary length with heterogeneous element types
-MixedTupleType = TypeVarTuple("MixedTupleType")
+    # ParamSpec representing the full signature (positional and keyword parameters) of a
+    # callable
+    P = ParamSpec("P")
+    # TypeVar representing the return type of a callable
+    R = TypeVar("R")
+    # Generic type variable for use in type constructors
+    T = TypeVar("T")
+    # Variadic TypeVar for tuples of arbitrary length with heterogeneous element types
+    MixedTupleType = TypeVarTuple("MixedTupleType")