Revert "remove unused python<3.6 code"

This reverts commit 0a6d271121.

src/Mod/Part/App/AppPartPy.cpp

@@ -1912,8 +1912,11 @@ private:
             if (!p) {
                 throw Py::TypeError("** makeWireString can't convert PyString.");
             }
+#if PY_VERSION_HEX >= 0x03030000
             pysize = PyUnicode_GetLength(p);
-
+#else
+            pysize = PyUnicode_GetSize(p);
+#endif
 #if PY_VERSION_HEX < 0x03090000
             unichars = PyUnicode_AS_UNICODE(p);
 #else
@@ -1921,8 +1924,11 @@ private:
 #endif
         }
         else if (PyUnicode_Check(intext)) {
+#if PY_VERSION_HEX >= 0x03030000
             pysize = PyUnicode_GetLength(intext);
-
+#else
+            pysize = PyUnicode_GetSize(intext);
+#endif
 #if PY_VERSION_HEX < 0x03090000
             unichars = PyUnicode_AS_UNICODE(intext);
 #else

src/Tools/generateTemplates/templateClassPyExport.py

@@ -422,9 +422,11 @@ PyNumberMethods @self.export.Name@::Number[] = { {
     number_divide_handler,    /*nb_true_divide*/
     nullptr,    /*nb_inplace_floor_divide*/
     nullptr,    /*nb_inplace_true_divide*/
-    nullptr,    /*nb_index*/
-    nullptr,    /*nb_matrix_multiply*/
-    nullptr     /*nb_inplace_matrix_multiply*/
+    nullptr     /*nb_index*/
+#if PY_VERSION_HEX >= 0x03050000
+   ,nullptr     /*nb_matrix_multiply*/
+   ,nullptr     /*nb_inplace_matrix_multiply*/
+#endif
 } };
 -