use typing-extensions

Author: basnijholt

adaptive/learner/balancing_learner.py

@@ -7,14 +7,19 @@
 from contextlib import suppress
 from functools import partial
 from operator import itemgetter
-from typing import Any, Callable, Dict, Literal, Sequence, Tuple, Union
+from typing import Any, Callable, Dict, Sequence, Tuple, Union
 
 import numpy as np
 
 from adaptive.learner.base_learner import BaseLearner
 from adaptive.notebook_integration import ensure_holoviews
 from adaptive.utils import cache_latest, named_product, restore
 
+try:
+    from typing import Literal
+except ImportError:
+    from typing_extensions import Literal
+
 
 def dispatch(child_functions: list[Callable], arg: Any) -> Any:
     index, x = arg

setup.py

@@ -32,6 +32,8 @@ def get_version_and_cmdclass(package_name):
     "cloudpickle",
     "loky >= 2.9",
 ]
+if sys.version_info < (3, 8):
+    install_requires.append("typing_extensions")
 
 extras_require = {
     "notebook": [