From 676f544dd059ef1e8300991d51c4ce750da51766 Mon Sep 17 00:00:00 2001
From: fecet <xiezej@gmail.com>
Date: Sat, 14 Sep 2024 17:02:05 +0800
Subject: [PATCH 1/3] feat: add support for pa.ExtensionType

---
 python/deltalake/schema.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/python/deltalake/schema.py b/python/deltalake/schema.py
index 8bc5c7e155..2008c43de0 100644
--- a/python/deltalake/schema.py
+++ b/python/deltalake/schema.py
@@ -95,6 +95,8 @@ def dtype_to_delta_dtype(dtype: pa.DataType) -> pa.DataType:
                 return pa.timestamp("us", "UTC")
         elif type(dtype) is pa.FixedSizeBinaryType:
             return pa.binary()
+        elif isinstance(dtype, pa.ExtensionType):
+            return dtype.storage_type
         try:
             return dtype_map[dtype]
         except KeyError:

From 899170b94d23879abf2244f54ba4a28e2747c2a7 Mon Sep 17 00:00:00 2001
From: fecet <xiezej@gmail.com>
Date: Sat, 14 Sep 2024 18:03:15 +0800
Subject: [PATCH 2/3] add test for ext type

---
 python/tests/test_schema.py | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/python/tests/test_schema.py b/python/tests/test_schema.py
index a3ad6b62e1..34c833eb17 100644
--- a/python/tests/test_schema.py
+++ b/python/tests/test_schema.py
@@ -223,6 +223,26 @@ def test_delta_schema():
     assert schema_without_metadata == Schema.from_pyarrow(pa_schema)
 
 
+def _generate_test_type():
+    class UuidType(pa.ExtensionType):
+        def __init__(self):
+            pa.ExtensionType.__init__(self, pa.binary(16), "my_package.uuid")
+
+        def __arrow_ext_serialize__(self):
+            # since we don't have a parameterized type, we don't need extra
+            # metadata to be deserialized
+            return b""
+
+        @classmethod
+        def __arrow_ext_deserialize__(self, storage_type, serialized):
+            # return an instance of this subclass given the serialized
+            # metadata.
+            return UuidType()
+
+    pa.register_extension_type(UuidType())
+    return UuidType()
+
+
 def _generate_test_tuples():
     test_tuples = [
         (
@@ -515,6 +535,11 @@ def _generate_test_tuples():
             ),
             ArrowSchemaConversionMode.NORMAL,
         ),
+        (
+            pa.schema([("uuid", _generate_test_type())]),
+            pa.schema([("uuid", pa.binary(16))]),
+            ArrowSchemaConversionMode.NORMAL,
+        ),
     ]
 
     return test_tuples

From 125f9bff10620f9b0ef04d1a9bd3465d5a3e2129 Mon Sep 17 00:00:00 2001
From: fecet <xiezej@gmail.com>
Date: Sun, 15 Sep 2024 00:24:10 +0800
Subject: [PATCH 3/3] make mypy happy

---
 python/stubs/pyarrow/__init__.pyi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/python/stubs/pyarrow/__init__.pyi b/python/stubs/pyarrow/__init__.pyi
index e500d11191..31943db8b8 100644
--- a/python/stubs/pyarrow/__init__.pyi
+++ b/python/stubs/pyarrow/__init__.pyi
@@ -14,6 +14,7 @@ FixedSizeListType: Any
 LargeListViewType: Any
 ListViewType: Any
 FixedSizeBinaryType: Any
+ExtensionType: Any
 schema: Any
 map_: Any
 list_: Any