Added py_str_or_bytes property (#91)

This will try and decoded the payload using UTF-8 and if that fails returns it as bytes.

src/amulet_nbt/__init__.pyi

@@ -313,6 +313,10 @@ class StringTag(AbstractBaseImmutableTag):
     def py_bytes(self) -> bytes:
         """The bytes stored in the class."""
 
+    @property
+    def py_str_or_bytes(self) -> str | bytes:
+        """If the payload is UTF-8 returns a string else returns bytes."""
+
     def __ge__(self, other: Any) -> bool:
         """Check if the tag is greater than or equal to another tag."""
 

src/amulet_nbt/pybind/tag/py_string_tag.cpp

@@ -58,6 +58,17 @@ void init_string(py::module& m) {
                 "The bytes stored in the class."
             )
         );
+        StringTag.def_property_readonly(
+            "py_str_or_bytes",
+            [](const AmuletNBT::StringTag& self) -> std::variant<py::str, py::bytes> {
+                try {
+                    return py::str(self);
+                } catch (py::error_already_set&){
+                    return py::bytes(self);
+                }
+            },
+            py::doc("If the payload is UTF-8 returns a string else returns bytes.")
+        );
         StringTag.def_property_readonly(
             "py_data",
             [](const AmuletNBT::StringTag& self){

tests/test_amulet_nbt/test_tag/test_string.py

@@ -41,6 +41,13 @@ def test_py_data(self) -> None:
 
         self.assertEqual(b"value", StringTag("value").py_bytes)
 
+        self.assertIsInstance(StringTag("test").py_str_or_bytes, str)
+        self.assertEqual("test", StringTag("test").py_str_or_bytes)
+        self.assertIsInstance(StringTag("test").py_str_or_bytes, str)
+        self.assertEqual("test", StringTag("test").py_str_or_bytes)
+        self.assertIsInstance(StringTag(b"test\xFF").py_str_or_bytes, bytes)
+        self.assertEqual(b"test\xFF", StringTag(b"test\xFF").py_str_or_bytes)
+
     def test_repr(self) -> None:
         self.assertEqual("StringTag('')", repr(StringTag()))
         self.assertEqual("StringTag('value')", repr(StringTag("value")))