Fix inconsistent Python union creator function naming (#8981)

tests/union_name_test/Bar.py

@@ -0,0 +1,93 @@
+# automatically generated by the FlatBuffers compiler, do not modify
+
+# namespace: union_name_test
+
+import flatbuffers
+from flatbuffers.compat import import_numpy
+np = import_numpy()
+
+class Bar(object):
+    __slots__ = ['_tab']
+
+    @classmethod
+    def GetRootAs(cls, buf, offset=0):
+        n = flatbuffers.encode.Get(flatbuffers.packer.uoffset, buf, offset)
+        x = Bar()
+        x.Init(buf, n + offset)
+        return x
+
+    @classmethod
+    def GetRootAsBar(cls, buf, offset=0):
+        """This method is deprecated. Please switch to GetRootAs."""
+        return cls.GetRootAs(buf, offset)
+    # Bar
+    def Init(self, buf, pos):
+        self._tab = flatbuffers.table.Table(buf, pos)
+
+    # Bar
+    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
+
+def BarStart(builder):
+    builder.StartObject(1)
+
+def Start(builder):
+    BarStart(builder)
+
+def BarAddName(builder, name):
+    builder.PrependUOffsetTRelativeSlot(0, flatbuffers.number_types.UOffsetTFlags.py_type(name), 0)
+
+def AddName(builder, name):
+    BarAddName(builder, name)
+
+def BarEnd(builder):
+    return builder.EndObject()
+
+def End(builder):
+    return BarEnd(builder)
+
+
+class BarT(object):
+
+    # BarT
+    def __init__(
+        self,
+        name = None,
+    ):
+        self.name = name  # type: Optional[str]
+
+    @classmethod
+    def InitFromBuf(cls, buf, pos):
+        bar = Bar()
+        bar.Init(buf, pos)
+        return cls.InitFromObj(bar)
+
+    @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, bar):
+        x = BarT()
+        x._UnPack(bar)
+        return x
+
+    # BarT
+    def _UnPack(self, bar):
+        if bar is None:
+            return
+        self.name = bar.Name()
+
+    # BarT
+    def Pack(self, builder):
+        if self.name is not None:
+            name = builder.CreateString(self.name)
+        BarStart(builder)
+        if self.name is not None:
+            BarAddName(builder, name)
+        bar = BarEnd(builder)
+        return bar