apacheGH-40092: [Python] Support Binary/StringView conversion to nump…

…y/pandas (apache#40093) Last step for Binary/StringView support in Python (apache#39633), now adding it to the arrow->pandas/numpy conversion code path. * Closes: apache#40092 Authored-by: Joris Van den Bossche <[email protected]> Signed-off-by: Joris Van den Bossche <[email protected]>
thisisnic · Mar 8, 2024 · 22c529e · 22c529e
1 parent f3d4b72
commit 22c529e
Show file tree

Hide file tree

Showing 2 changed files with 33 additions and 3 deletions.
diff --git a/python/pyarrow/src/arrow/python/arrow_to_pandas.cc b/python/pyarrow/src/arrow/python/arrow_to_pandas.cc
@@ -133,6 +133,13 @@ struct WrapBytes<LargeStringType> {
   }
 };
 
+template <>
+struct WrapBytes<StringViewType> {
+  static inline PyObject* Wrap(const char* data, int64_t length) {
+    return PyUnicode_FromStringAndSize(data, length);
+  }
+};
+
 template <>
 struct WrapBytes<BinaryType> {
   static inline PyObject* Wrap(const char* data, int64_t length) {
@@ -147,6 +154,13 @@ struct WrapBytes<LargeBinaryType> {
   }
 };
 
+template <>
+struct WrapBytes<BinaryViewType> {
+  static inline PyObject* Wrap(const char* data, int64_t length) {
+    return PyBytes_FromStringAndSize(data, length);
+  }
+};
+
 template <>
 struct WrapBytes<FixedSizeBinaryType> {
   static inline PyObject* Wrap(const char* data, int64_t length) {
@@ -1154,7 +1168,8 @@ struct ObjectWriterVisitor {
   }
 
   template <typename Type>
-  enable_if_t<is_base_binary_type<Type>::value || is_fixed_size_binary_type<Type>::value,
+  enable_if_t<is_base_binary_type<Type>::value || is_binary_view_like_type<Type>::value ||
+                  is_fixed_size_binary_type<Type>::value,
               Status>
   Visit(const Type& type) {
     auto WrapValue = [](const std::string_view& view, PyObject** out) {
@@ -1355,8 +1370,7 @@ struct ObjectWriterVisitor {
                   std::is_same<ExtensionType, Type>::value ||
                   (std::is_base_of<IntervalType, Type>::value &&
                    !std::is_same<MonthDayNanoIntervalType, Type>::value) ||
-                  std::is_base_of<UnionType, Type>::value ||
-                  std::is_base_of<BinaryViewType, Type>::value,
+                  std::is_base_of<UnionType, Type>::value,
               Status>
   Visit(const Type& type) {
     return Status::NotImplemented("No implemented conversion to object dtype: ",
@@ -2086,8 +2100,10 @@ static Status GetPandasWriterType(const ChunkedArray& data, const PandasOptions&
       break;
     case Type::STRING:        // fall through
     case Type::LARGE_STRING:  // fall through
+    case Type::STRING_VIEW:   // fall through
     case Type::BINARY:        // fall through
     case Type::LARGE_BINARY:
+    case Type::BINARY_VIEW:
     case Type::NA:                       // fall through
     case Type::FIXED_SIZE_BINARY:        // fall through
     case Type::STRUCT:                   // fall through

diff --git a/python/pyarrow/tests/test_pandas.py b/python/pyarrow/tests/test_pandas.py
@@ -1760,6 +1760,20 @@ def test_large_string(self):
         _check_pandas_roundtrip(
             df, schema=pa.schema([('a', pa.large_string())]))
 
+    def test_binary_view(self):
+        s = pd.Series([b'123', b'', b'a', None])
+        _check_series_roundtrip(s, type_=pa.binary_view())
+        df = pd.DataFrame({'a': s})
+        _check_pandas_roundtrip(
+            df, schema=pa.schema([('a', pa.binary_view())]))
+
+    def test_string_view(self):
+        s = pd.Series(['123', '', 'a', None])
+        _check_series_roundtrip(s, type_=pa.string_view())
+        df = pd.DataFrame({'a': s})
+        _check_pandas_roundtrip(
+            df, schema=pa.schema([('a', pa.string_view())]))
+
     def test_table_empty_str(self):
         values = ['', '', '', '', '']
         df = pd.DataFrame({'strings': values})