commit 448801da96c70699e2ca0798efdfe86d45f37f06
author Dennis Sweeney <36520290+sweeneyde@users.noreply.github.com> Tue Mar 16 00:02:25 2021 -0400
committer GitHub <noreply@github.com> Mon Mar 15 21:02:25 2021 -0700
tree babbdb97bfc46fffe4cb0f938c95154b53b22665
parent d69ae758a0606c142c305123dcbad3e3e42d664f

bpo-41361: Optimized argument parsing for deque_rotate (GH-24796)

Modules/_collectionsmodule.c

diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c
index 90bafb0..ca63f71 100644
--- a/Modules/_collectionsmodule.c
+++ b/Modules/_collectionsmodule.c
@@ -880,9 +880,20 @@ deque_rotate(dequeobject *deque, PyObject *const *args, Py_ssize_t nargs)
 {
     Py_ssize_t n=1;
 
-    if (!_PyArg_ParseStack(args, nargs, "|n:rotate", &n)) {
+    if (!_PyArg_CheckPositional("deque.rotate", nargs, 0, 1)) {
         return NULL;
     }
+    if (nargs) {
+        PyObject *index = _PyNumber_Index(args[0]);
+        if (index == NULL) {
+            return NULL;
+        }
+        n = PyLong_AsSsize_t(index);
+        Py_DECREF(index);
+        if (n == -1 && PyErr_Occurred()) {
+            return NULL;
+        }
+    }
 
     if (!_deque_rotate(deque, n))
         Py_RETURN_NONE;