Use basedpyright refactor

folkugat_web/utils.py

@@ -1,6 +1,22 @@
 import itertools
+from collections.abc import Callable, Iterable, Iterator
+from typing import Protocol, Self, TypeVar
 
 
-def groupby(it, key_fn=lambda x: x, group_fn=lambda x: x):
+class SupportsLessThan(Protocol):
+    def __lt__(self, other: Self) -> bool:
+        raise NotImplementedError()
+
+
+T = TypeVar("T")
+KeyT = TypeVar("KeyT", bound=SupportsLessThan)
+GroupT = TypeVar("GroupT")
+
+
+def groupby(
+    it: Iterable[T],
+    key_fn: Callable[[T], KeyT],
+    group_fn: Callable[[Iterable[T]], GroupT] = lambda x: x,
+) -> Iterator[tuple[KeyT, GroupT]]:
     for k, g in itertools.groupby(sorted(it, key=key_fn), key=key_fn):
         yield k, group_fn(g)