RustPython · youknowone · Aug 2, 2026 · Jul 31, 2026 · Jul 31, 2026 · Jul 31, 2026
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -305,7 +305,6 @@ textwrap = { version = "0.16.2", default-features = false }
 termios = "0.3.3"
 thiserror = "2.0"
 thin-vec = "0.2.14"
-timsort = "0.1.2"
 tk-sys = { git = "https://github.com/arihant2math/tkinter.git", tag = "v0.2.0" }
 icu_casemap = "2"
 icu_locale = "2"

diff --git a/crates/vm/Cargo.toml b/crates/vm/Cargo.toml
@@ -80,7 +80,6 @@ half = { workspace = true }
 psm = { workspace = true }
 optional = { workspace = true }
 result-like = { workspace = true }
-timsort = { workspace = true }
 
 [target.'cfg(unix)'.dependencies]
 exitcode = { workspace = true }

diff --git a/crates/vm/src/builtins/list.rs b/crates/vm/src/builtins/list.rs
@@ -18,6 +18,7 @@ use crate::{
     recursion::ReprGuard,
     sequence::{MutObjectSequenceOp, OptionalRangeArgs, SequenceExt, SequenceMutExt},
     sliceable::{SequenceIndex, SliceableSequenceMutOp, SliceableSequenceOp},
+    sorting::timsort,
     types::{
         AsMapping, AsSequence, Comparable, Constructor, Initializer, IterNext, Iterable,
         PyComparisonOp, Representable, SelfIter,
@@ -641,14 +642,15 @@ fn do_sort(
     reverse: bool,
 ) -> PyResult<()> {
     // CPython uses __lt__ for all comparisons in sort.
-    // try_sort_by_gt expects is_gt(a, b) = true when a should come AFTER b.
-    let cmp = |a: &PyObjectRef, b: &PyObjectRef| {
+    // `timsort` expects is_lt(a, b) = true when a must be placed BEFORE b.
+    // For reverse=True, swapping the operands yields a descending order that is
+    // still stable in the original relative order, matching CPython's
+    // reverse-sort-reverse approach.
+    let mut is_lt = |a: &PyObjectRef, b: &PyObjectRef| {
         if reverse {
-            // Descending: a comes after b when a < b
-            a.rich_compare_bool(b, PyComparisonOp::Lt, vm)
-        } else {
-            // Ascending: a comes after b when b < a
             b.rich_compare_bool(a, PyComparisonOp::Lt, vm)
+        } else {
+            a.rich_compare_bool(b, PyComparisonOp::Lt, vm)
         }
     };
 
@@ -657,10 +659,10 @@ fn do_sort(
             .iter()
             .map(|x| Ok((x.clone(), key_func.call((x.clone(),), vm)?)))
             .collect::<Result<Vec<_>, _>>()?;
-        timsort::try_sort_by_gt(&mut items, |a, b| cmp(&a.1, &b.1))?;
+        timsort(&mut items, &mut |a, b| is_lt(&a.1, &b.1))?;
         *values = items.into_iter().map(|(val, _)| val).collect();
     } else {
-        timsort::try_sort_by_gt(values, cmp)?;
+        timsort(values, &mut is_lt)?;
     }
 
     Ok(())

diff --git a/crates/vm/src/lib.rs b/crates/vm/src/lib.rs
@@ -92,6 +92,7 @@ pub mod scope;
 pub mod sequence;
 pub mod signal;
 pub mod sliceable;
+pub mod sorting;
 pub mod stdlib;
 pub mod suggestion;
 pub mod types;