GH-49505: [Python] Implement DictionaryArray converter for type pa.large_string and pa.large_binary

cpp/src/arrow/util/converter.h

@@ -238,7 +238,9 @@ struct MakeConverterImpl {
       DICTIONARY_CASE(FloatType);
       DICTIONARY_CASE(DoubleType);
       DICTIONARY_CASE(BinaryType);
+      DICTIONARY_CASE(LargeBinaryType);
       DICTIONARY_CASE(StringType);
+      DICTIONARY_CASE(LargeStringType);
       DICTIONARY_CASE(FixedSizeBinaryType);
 #undef DICTIONARY_CASE
       default:

python/pyarrow/src/arrow/python/python_to_arrow.cc

@@ -24,6 +24,7 @@
 #include <limits>
 #include <sstream>
 #include <string>
+#include <string_view>
 #include <utility>
 #include <vector>
 
@@ -826,7 +827,7 @@ class PyDictionaryConverter<U, enable_if_has_string_view<U>>
     } else {
       ARROW_RETURN_NOT_OK(
           PyValue::Convert(this->value_type_, this->options_, value, view_));
-      return this->value_builder_->Append(view_.bytes, static_cast<int32_t>(view_.size));
+      return this->value_builder_->Append(std::string_view(view_.bytes, view_.size));
     }
   }
 

python/pyarrow/tests/test_array.py

@@ -4468,3 +4468,19 @@ def test_dunders_checked_overflow():
         arr ** pa.scalar(2, type=pa.int8())
     with pytest.raises(pa.ArrowInvalid, match=error_match):
         arr / (-arr)
+
+
+def test_dictionary_large_string_and_binary():
+    # Test dictionary with large_string values
+    arr_str = pa.array(
+        ["a", "b", "a"], type=pa.dictionary(pa.int32(), pa.large_string())
+    )
+    assert arr_str.type.value_type == pa.large_string()
+    assert arr_str.to_pylist() == ["a", "b", "a"]
+
+    # Test dictionary with large_binary values
+    arr_bin = pa.array(
+        [b"x", b"y", b"x"], type=pa.dictionary(pa.int32(), pa.large_binary())
+    )
+    assert arr_bin.type.value_type == pa.large_binary()
+    assert arr_bin.to_pylist() == [b"x", b"y", b"x"]