fix(ops): align kwargs for tree_reduce with functools.reduce with the Python C implementation

.pre-commit-config.yaml

@@ -29,7 +29,7 @@ repos:
       - id: clang-format
         stages: [commit, push, manual]
   - repo: https://github.com/charliermarsh/ruff-pre-commit
-    rev: v0.0.255
+    rev: v0.0.257
     hooks:
       - id: ruff
         args: [--fix, --exit-non-zero-on-fix]

optree/ops.py

@@ -895,7 +895,7 @@ def tree_reduce(
 def tree_reduce(
     func: Callable[[T, T], T],
     tree: PyTree[T],
-    initializer: T = __MISSING,
+    initial: T = __MISSING,
     *,
     is_leaf: Callable[[T], bool] | None = None,
     none_is_leaf: bool = False,
@@ -907,7 +907,7 @@ def tree_reduce(
 def tree_reduce(
     func,
     tree,
-    initializer=__MISSING,
+    initial=__MISSING,
     *,
     is_leaf=None,
     none_is_leaf=False,
@@ -929,8 +929,8 @@ def tree_reduce(
     Args:
         func (callable): A function that takes two arguments and returns a value of the same type.
         tree (pytree): A pytree to be traversed.
-        initializer (object, optional): An initial value to be used for the reduction. If not
-            provided, the first leaf value is used as the initial value.
+        initial (object, optional): An initial value to be used for the reduction. If not provided,
+            the first leaf value is used as the initial value.
         is_leaf (callable, optional): An optionally specified function that will be called at each
             flattening step. It should return a boolean, with :data:`True` stopping the traversal
             and the whole subtree being treated as a leaf, and :data:`False` indicating the
@@ -946,9 +946,9 @@ def tree_reduce(
         The result of reducing the leaves of the pytree using ``func``.
     """  # pylint: disable=line-too-long
     leaves = tree_leaves(tree, is_leaf, none_is_leaf=none_is_leaf, namespace=namespace)
-    if initializer is __MISSING:
+    if initial is __MISSING:
         return functools.reduce(func, leaves)
-    return functools.reduce(func, leaves, initializer)
+    return functools.reduce(func, leaves, initial)
 
 
 def tree_sum(

optree/typing.py

@@ -153,7 +153,7 @@ class PyTree(Generic[T]):  # pylint: disable=too-few-public-methods
     """
 
     @_tp_cache
-    def __class_getitem__(  # noqa: C901
+    def __class_getitem__(
         cls,
         item: T | tuple[T] | tuple[T, str | None],
     ) -> TypeAlias: