Clarifying nonlocal documtation: SyntaxError is thrown if nearest enclosing scope is global

Author: quazi-irfan

Doc/reference/simple_stmts.rst

@@ -1011,7 +1011,9 @@ The :keyword:`nonlocal` statement causes the listed identifiers to refer to
 previously bound variables in the nearest enclosing scope excluding globals.
 This is important because the default behavior for binding is to search the
 local namespace first.  The statement allows encapsulated code to rebind
-variables outside of the local scope besides the global (module) scope.
+variables outside of the local scope besides the global scope. A :exc:`SyntaxError`
+will be raised if the nearest enclosing scope is the global (module) scope.
+
 
 Names listed in a :keyword:`nonlocal` statement, unlike those listed in a
 :keyword:`global` statement, must refer to pre-existing bindings in an