From 6bcdf38ed05115469b7e23d29120aad63cb5bb64 Mon Sep 17 00:00:00 2001
From: Luke Manley <lukemanley@gmail.com>
Date: Wed, 8 Jan 2025 16:59:03 -0500
Subject: [PATCH] fix: Fix `Int128` dtype serialization

---
 crates/polars-core/src/datatypes/_serde.rs | 3 +++
 py-polars/tests/unit/io/test_pickle.py     | 7 ++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/crates/polars-core/src/datatypes/_serde.rs b/crates/polars-core/src/datatypes/_serde.rs
index 5cc1d7f86c94..3c2a38a34ce8 100644
--- a/crates/polars-core/src/datatypes/_serde.rs
+++ b/crates/polars-core/src/datatypes/_serde.rs
@@ -85,6 +85,7 @@ enum SerializableDataType {
     Int16,
     Int32,
     Int64,
+    Int128,
     Float32,
     Float64,
     String,
@@ -130,6 +131,7 @@ impl From<&DataType> for SerializableDataType {
             Int16 => Self::Int16,
             Int32 => Self::Int32,
             Int64 => Self::Int64,
+            Int128 => Self::Int128,
             Float32 => Self::Float32,
             Float64 => Self::Float64,
             String => Self::String,
@@ -186,6 +188,7 @@ impl From<SerializableDataType> for DataType {
             Int16 => Self::Int16,
             Int32 => Self::Int32,
             Int64 => Self::Int64,
+            Int128 => Self::Int128,
             Float32 => Self::Float32,
             Float64 => Self::Float64,
             String => Self::String,
diff --git a/py-polars/tests/unit/io/test_pickle.py b/py-polars/tests/unit/io/test_pickle.py
index 7f8beb6ca7c6..5b798cbda2eb 100644
--- a/py-polars/tests/unit/io/test_pickle.py
+++ b/py-polars/tests/unit/io/test_pickle.py
@@ -19,7 +19,12 @@ def test_pickle() -> None:
 
 
 def test_pickle_expr() -> None:
-    for e in [pl.all(), pl.len(), pl.duration(weeks=10, days=20, hours=3)]:
+    for e in [
+        pl.all(),
+        pl.len(),
+        pl.duration(weeks=10, days=20, hours=3),
+        pl.col("a").cast(pl.Int128),
+    ]:
         f = io.BytesIO()
         pickle.dump(e, f)