could do extra['myvariable'] in templates

src/rougail/template/base.py

@@ -184,6 +184,11 @@ class RougailExtra:
         except KeyError:
             raise AttributeError(f'unable to find extra "{key}"')
 
+    def __getitem__(self,
+                    key: str,
+                    ) -> Any:
+        return self.__getattr__(key)
+
     def __iter__(self):
         return iter(self._suboption.values())