diff --git a/tests/MyGame/Example/NestedUnion/Any.py b/tests/MyGame/Example/NestedUnion/Any.py
new file mode 100644
index 0000000..e0b8594
--- /dev/null
+++ b/tests/MyGame/Example/NestedUnion/Any.py
@@ -0,0 +1,20 @@
+# automatically generated by the FlatBuffers compiler, do not modify
+
+# namespace: NestedUnion
+
+class Any(object):
+    NONE = 0
+    Vec3 = 1
+    TestSimpleTableWithEnum = 2
+
+def AnyCreator(unionType, table):
+    from flatbuffers.table import Table
+    if not isinstance(table, Table):
+        return None
+    if unionType == Any().Vec3:
+        import MyGame.Example.NestedUnion.Vec3
+        return MyGame.Example.NestedUnion.Vec3.Vec3T.InitFromBuf(table.Bytes, table.Pos)
+    if unionType == Any().TestSimpleTableWithEnum:
+        import MyGame.Example.NestedUnion.TestSimpleTableWithEnum
+        return MyGame.Example.NestedUnion.TestSimpleTableWithEnum.TestSimpleTableWithEnumT.InitFromBuf(table.Bytes, table.Pos)
+    return None
diff --git a/tests/MyGame/Example/NestedUnion/Color.py b/tests/MyGame/Example/NestedUnion/Color.py
new file mode 100644
index 0000000..6ba9ca1
--- /dev/null
+++ b/tests/MyGame/Example/NestedUnion/Color.py
@@ -0,0 +1,12 @@
+# automatically generated by the FlatBuffers compiler, do not modify
+
+# namespace: NestedUnion
+
+# Composite components of Monster color.
+class Color(object):
+    Red = 1
+    # \brief color Green
+    # Green is bit_flag with value (1u << 1)
+    Green = 2
+    # \brief color Blue (1u << 3)
+    Blue = 8
diff --git a/tests/MyGame/Example/NestedUnion/NestedUnionTest.py b/tests/MyGame/Example/NestedUnion/NestedUnionTest.py
new file mode 100644
index 0000000..9a3cbee
--- /dev/null
+++ b/tests/MyGame/Example/NestedUnion/NestedUnionTest.py
@@ -0,0 +1,133 @@
+# automatically generated by the FlatBuffers compiler, do not modify
+
+# namespace: NestedUnion
+
+import flatbuffers
+from flatbuffers.compat import import_numpy
+np = import_numpy()
+
+class NestedUnionTest(object):
+    __slots__ = ['_tab']
+
+    @classmethod
+    def GetRootAs(cls, buf, offset=0):
+        n = flatbuffers.encode.Get(flatbuffers.packer.uoffset, buf, offset)
+        x = NestedUnionTest()
+        x.Init(buf, n + offset)
+        return x
+
+    @classmethod
+    def GetRootAsNestedUnionTest(cls, buf, offset=0):
+        """This method is deprecated. Please switch to GetRootAs."""
+        return cls.GetRootAs(buf, offset)
+    # NestedUnionTest
+    def Init(self, buf, pos):
+        self._tab = flatbuffers.table.Table(buf, pos)
+
+    # NestedUnionTest
+    def Name(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(4))
+        if o != 0:
+            return self._tab.String(o + self._tab.Pos)
+        return None
+
+    # NestedUnionTest
+    def DataType(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(6))
+        if o != 0:
+            return self._tab.Get(flatbuffers.number_types.Uint8Flags, o + self._tab.Pos)
+        return 0
+
+    # NestedUnionTest
+    def Data(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(8))
+        if o != 0:
+            from flatbuffers.table import Table
+            obj = Table(bytearray(), 0)
+            self._tab.Union(obj, o)
+            return obj
+        return None
+
+    # NestedUnionTest
+    def Id(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(10))
+        if o != 0:
+            return self._tab.Get(flatbuffers.number_types.Int16Flags, o + self._tab.Pos)
+        return 0
+
+def NestedUnionTestStart(builder): builder.StartObject(4)
+def Start(builder):
+    return NestedUnionTestStart(builder)
+def NestedUnionTestAddName(builder, name): builder.PrependUOffsetTRelativeSlot(0, flatbuffers.number_types.UOffsetTFlags.py_type(name), 0)
+def AddName(builder, name):
+    return NestedUnionTestAddName(builder, name)
+def NestedUnionTestAddDataType(builder, dataType): builder.PrependUint8Slot(1, dataType, 0)
+def AddDataType(builder, dataType):
+    return NestedUnionTestAddDataType(builder, dataType)
+def NestedUnionTestAddData(builder, data): builder.PrependUOffsetTRelativeSlot(2, flatbuffers.number_types.UOffsetTFlags.py_type(data), 0)
+def AddData(builder, data):
+    return NestedUnionTestAddData(builder, data)
+def NestedUnionTestAddId(builder, id): builder.PrependInt16Slot(3, id, 0)
+def AddId(builder, id):
+    return NestedUnionTestAddId(builder, id)
+def NestedUnionTestEnd(builder): return builder.EndObject()
+def End(builder):
+    return NestedUnionTestEnd(builder)
+import MyGame.Example.NestedUnion.Any
+import MyGame.Example.NestedUnion.TestSimpleTableWithEnum
+import MyGame.Example.NestedUnion.Vec3
+try:
+    from typing import Union
+except:
+    pass
+
+class NestedUnionTestT(object):
+
+    # NestedUnionTestT
+    def __init__(self):
+        self.name = None  # type: str
+        self.dataType = 0  # type: int
+        self.data = None  # type: Union[None, MyGame.Example.NestedUnion.Vec3.Vec3T, MyGame.Example.NestedUnion.TestSimpleTableWithEnum.TestSimpleTableWithEnumT]
+        self.id = 0  # type: int
+
+    @classmethod
+    def InitFromBuf(cls, buf, pos):
+        nestedUnionTest = NestedUnionTest()
+        nestedUnionTest.Init(buf, pos)
+        return cls.InitFromObj(nestedUnionTest)
+
+    @classmethod
+    def InitFromPackedBuf(cls, buf, pos=0):
+        n = flatbuffers.encode.Get(flatbuffers.packer.uoffset, buf, pos)
+        return cls.InitFromBuf(buf, pos+n)
+
+    @classmethod
+    def InitFromObj(cls, nestedUnionTest):
+        x = NestedUnionTestT()
+        x._UnPack(nestedUnionTest)
+        return x
+
+    # NestedUnionTestT
+    def _UnPack(self, nestedUnionTest):
+        if nestedUnionTest is None:
+            return
+        self.name = nestedUnionTest.Name()
+        self.dataType = nestedUnionTest.DataType()
+        self.data = MyGame.Example.NestedUnion.Any.AnyCreator(self.dataType, nestedUnionTest.Data())
+        self.id = nestedUnionTest.Id()
+
+    # NestedUnionTestT
+    def Pack(self, builder):
+        if self.name is not None:
+            name = builder.CreateString(self.name)
+        if self.data is not None:
+            data = self.data.Pack(builder)
+        NestedUnionTestStart(builder)
+        if self.name is not None:
+            NestedUnionTestAddName(builder, name)
+        NestedUnionTestAddDataType(builder, self.dataType)
+        if self.data is not None:
+            NestedUnionTestAddData(builder, data)
+        NestedUnionTestAddId(builder, self.id)
+        nestedUnionTest = NestedUnionTestEnd(builder)
+        return nestedUnionTest
diff --git a/tests/MyGame/Example/NestedUnion/Test.py b/tests/MyGame/Example/NestedUnion/Test.py
new file mode 100644
index 0000000..143d1df
--- /dev/null
+++ b/tests/MyGame/Example/NestedUnion/Test.py
@@ -0,0 +1,66 @@
+# automatically generated by the FlatBuffers compiler, do not modify
+
+# namespace: NestedUnion
+
+import flatbuffers
+from flatbuffers.compat import import_numpy
+np = import_numpy()
+
+class Test(object):
+    __slots__ = ['_tab']
+
+    @classmethod
+    def SizeOf(cls):
+        return 4
+
+    # Test
+    def Init(self, buf, pos):
+        self._tab = flatbuffers.table.Table(buf, pos)
+
+    # Test
+    def A(self): return self._tab.Get(flatbuffers.number_types.Int16Flags, self._tab.Pos + flatbuffers.number_types.UOffsetTFlags.py_type(0))
+    # Test
+    def B(self): return self._tab.Get(flatbuffers.number_types.Int8Flags, self._tab.Pos + flatbuffers.number_types.UOffsetTFlags.py_type(2))
+
+def CreateTest(builder, a, b):
+    builder.Prep(2, 4)
+    builder.Pad(1)
+    builder.PrependInt8(b)
+    builder.PrependInt16(a)
+    return builder.Offset()
+
+
+class TestT(object):
+
+    # TestT
+    def __init__(self):
+        self.a = 0  # type: int
+        self.b = 0  # type: int
+
+    @classmethod
+    def InitFromBuf(cls, buf, pos):
+        test = Test()
+        test.Init(buf, pos)
+        return cls.InitFromObj(test)
+
+    @classmethod
+    def InitFromPackedBuf(cls, buf, pos=0):
+        n = flatbuffers.encode.Get(flatbuffers.packer.uoffset, buf, pos)
+        return cls.InitFromBuf(buf, pos+n)
+
+    @classmethod
+    def InitFromObj(cls, test):
+        x = TestT()
+        x._UnPack(test)
+        return x
+
+    # TestT
+    def _UnPack(self, test):
+        if test is None:
+            return
+        self.a = test.A()
+        self.b = test.B()
+
+    # TestT
+    def Pack(self, builder):
+        return CreateTest(builder, self.a, self.b)
diff --git a/tests/MyGame/Example/NestedUnion/TestSimpleTableWithEnum.py b/tests/MyGame/Example/NestedUnion/TestSimpleTableWithEnum.py
new file mode 100644
index 0000000..46ebc26
--- /dev/null
+++ b/tests/MyGame/Example/NestedUnion/TestSimpleTableWithEnum.py
@@ -0,0 +1,78 @@
+# automatically generated by the FlatBuffers compiler, do not modify
+
+# namespace: NestedUnion
+
+import flatbuffers
+from flatbuffers.compat import import_numpy
+np = import_numpy()
+
+class TestSimpleTableWithEnum(object):
+    __slots__ = ['_tab']
+
+    @classmethod
+    def GetRootAs(cls, buf, offset=0):
+        n = flatbuffers.encode.Get(flatbuffers.packer.uoffset, buf, offset)
+        x = TestSimpleTableWithEnum()
+        x.Init(buf, n + offset)
+        return x
+
+    @classmethod
+    def GetRootAsTestSimpleTableWithEnum(cls, buf, offset=0):
+        """This method is deprecated. Please switch to GetRootAs."""
+        return cls.GetRootAs(buf, offset)
+    # TestSimpleTableWithEnum
+    def Init(self, buf, pos):
+        self._tab = flatbuffers.table.Table(buf, pos)
+
+    # TestSimpleTableWithEnum
+    def Color(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(4))
+        if o != 0:
+            return self._tab.Get(flatbuffers.number_types.Uint8Flags, o + self._tab.Pos)
+        return 2
+
+def TestSimpleTableWithEnumStart(builder): builder.StartObject(1)
+def Start(builder):
+    return TestSimpleTableWithEnumStart(builder)
+def TestSimpleTableWithEnumAddColor(builder, color): builder.PrependUint8Slot(0, color, 2)
+def AddColor(builder, color):
+    return TestSimpleTableWithEnumAddColor(builder, color)
+def TestSimpleTableWithEnumEnd(builder): return builder.EndObject()
+def End(builder):
+    return TestSimpleTableWithEnumEnd(builder)
+
+class TestSimpleTableWithEnumT(object):
+
+    # TestSimpleTableWithEnumT
+    def __init__(self):
+        self.color = 2  # type: int
+
+    @classmethod
+    def InitFromBuf(cls, buf, pos):
+        testSimpleTableWithEnum = TestSimpleTableWithEnum()
+        testSimpleTableWithEnum.Init(buf, pos)
+        return cls.InitFromObj(testSimpleTableWithEnum)
+
+    @classmethod
+    def InitFromPackedBuf(cls, buf, pos=0):
+        n = flatbuffers.encode.Get(flatbuffers.packer.uoffset, buf, pos)
+        return cls.InitFromBuf(buf, pos+n)
+
+    @classmethod
+    def InitFromObj(cls, testSimpleTableWithEnum):
+        x = TestSimpleTableWithEnumT()
+        x._UnPack(testSimpleTableWithEnum)
+        return x
+
+    # TestSimpleTableWithEnumT
+    def _UnPack(self, testSimpleTableWithEnum):
+        if testSimpleTableWithEnum is None:
+            return
+        self.color = testSimpleTableWithEnum.Color()
+
+    # TestSimpleTableWithEnumT
+    def Pack(self, builder):
+        TestSimpleTableWithEnumStart(builder)
+        TestSimpleTableWithEnumAddColor(builder, self.color)
+        testSimpleTableWithEnum = TestSimpleTableWithEnumEnd(builder)
+        return testSimpleTableWithEnum
diff --git a/tests/MyGame/Example/NestedUnion/Vec3.py b/tests/MyGame/Example/NestedUnion/Vec3.py
new file mode 100644
index 0000000..f3bb75f
--- /dev/null
+++ b/tests/MyGame/Example/NestedUnion/Vec3.py
@@ -0,0 +1,155 @@
+# automatically generated by the FlatBuffers compiler, do not modify
+
+# namespace: NestedUnion
+
+import flatbuffers
+from flatbuffers.compat import import_numpy
+np = import_numpy()
+
+class Vec3(object):
+    __slots__ = ['_tab']
+
+    @classmethod
+    def GetRootAs(cls, buf, offset=0):
+        n = flatbuffers.encode.Get(flatbuffers.packer.uoffset, buf, offset)
+        x = Vec3()
+        x.Init(buf, n + offset)
+        return x
+
+    @classmethod
+    def GetRootAsVec3(cls, buf, offset=0):
+        """This method is deprecated. Please switch to GetRootAs."""
+        return cls.GetRootAs(buf, offset)
+    # Vec3
+    def Init(self, buf, pos):
+        self._tab = flatbuffers.table.Table(buf, pos)
+
+    # Vec3
+    def X(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(4))
+        if o != 0:
+            return self._tab.Get(flatbuffers.number_types.Float64Flags, o + self._tab.Pos)
+        return 0.0
+
+    # Vec3
+    def Y(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(6))
+        if o != 0:
+            return self._tab.Get(flatbuffers.number_types.Float64Flags, o + self._tab.Pos)
+        return 0.0
+
+    # Vec3
+    def Z(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(8))
+        if o != 0:
+            return self._tab.Get(flatbuffers.number_types.Float64Flags, o + self._tab.Pos)
+        return 0.0
+
+    # Vec3
+    def Test1(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(10))
+        if o != 0:
+            return self._tab.Get(flatbuffers.number_types.Float64Flags, o + self._tab.Pos)
+        return 0.0
+
+    # Vec3
+    def Test2(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(12))
+        if o != 0:
+            return self._tab.Get(flatbuffers.number_types.Uint8Flags, o + self._tab.Pos)
+        return 0
+
+    # Vec3
+    def Test3(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(14))
+        if o != 0:
+            x = o + self._tab.Pos
+            from MyGame.Example.NestedUnion.Test import Test
+            obj = Test()
+            obj.Init(self._tab.Bytes, x)
+            return obj
+        return None
+
+def Vec3Start(builder): builder.StartObject(6)
+def Start(builder):
+    return Vec3Start(builder)
+def Vec3AddX(builder, x): builder.PrependFloat64Slot(0, x, 0.0)
+def AddX(builder, x):
+    return Vec3AddX(builder, x)
+def Vec3AddY(builder, y): builder.PrependFloat64Slot(1, y, 0.0)
+def AddY(builder, y):
+    return Vec3AddY(builder, y)
+def Vec3AddZ(builder, z): builder.PrependFloat64Slot(2, z, 0.0)
+def AddZ(builder, z):
+    return Vec3AddZ(builder, z)
+def Vec3AddTest1(builder, test1): builder.PrependFloat64Slot(3, test1, 0.0)
+def AddTest1(builder, test1):
+    return Vec3AddTest1(builder, test1)
+def Vec3AddTest2(builder, test2): builder.PrependUint8Slot(4, test2, 0)
+def AddTest2(builder, test2):
+    return Vec3AddTest2(builder, test2)
+def Vec3AddTest3(builder, test3): builder.PrependStructSlot(5, flatbuffers.number_types.UOffsetTFlags.py_type(test3), 0)
+def AddTest3(builder, test3):
+    return Vec3AddTest3(builder, test3)
+def Vec3End(builder): return builder.EndObject()
+def End(builder):
+    return Vec3End(builder)
+import MyGame.Example.NestedUnion.Test
+try:
+    from typing import Optional
+except:
+    pass
+
+class Vec3T(object):
+
+    # Vec3T
+    def __init__(self):
+        self.x = 0.0  # type: float
+        self.y = 0.0  # type: float
+        self.z = 0.0  # type: float
+        self.test1 = 0.0  # type: float
+        self.test2 = 0  # type: int
+        self.test3 = None  # type: Optional[MyGame.Example.NestedUnion.Test.TestT]
+
+    @classmethod
+    def InitFromBuf(cls, buf, pos):
+        vec3 = Vec3()
+        vec3.Init(buf, pos)
+        return cls.InitFromObj(vec3)
+
+    @classmethod
+    def InitFromPackedBuf(cls, buf, pos=0):
+        n = flatbuffers.encode.Get(flatbuffers.packer.uoffset, buf, pos)
+        return cls.InitFromBuf(buf, pos+n)
+
+    @classmethod
+    def InitFromObj(cls, vec3):
+        x = Vec3T()
+        x._UnPack(vec3)
+        return x
+
+    # Vec3T
+    def _UnPack(self, vec3):
+        if vec3 is None:
+            return
+        self.x = vec3.X()
+        self.y = vec3.Y()
+        self.z = vec3.Z()
+        self.test1 = vec3.Test1()
+        self.test2 = vec3.Test2()
+        if vec3.Test3() is not None:
+            self.test3 = MyGame.Example.NestedUnion.Test.TestT.InitFromObj(vec3.Test3())
+
+    # Vec3T
+    def Pack(self, builder):
+        Vec3Start(builder)
+        Vec3AddX(builder, self.x)
+        Vec3AddY(builder, self.y)
+        Vec3AddZ(builder, self.z)
+        Vec3AddTest1(builder, self.test1)
+        Vec3AddTest2(builder, self.test2)
+        if self.test3 is not None:
+            test3 = self.test3.Pack(builder)
+            Vec3AddTest3(builder, test3)
+        vec3 = Vec3End(builder)
+        return vec3
diff --git a/tests/MyGame/Example/NestedUnion/__init__.py b/tests/MyGame/Example/NestedUnion/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/tests/MyGame/Example/NestedUnion/__init__.py