give a better error message when deleting ()

2 files changed, 13 insertions, 4 deletions

diff --git a/Lib/test/test_syntax.py b/Lib/test/test_syntax.py
index c1027b1..26d78ad 100644
--- a/Lib/test/test_syntax.py
+++ b/Lib/test/test_syntax.py
@@ -462,6 +462,12 @@ Traceback (most recent call last):
   File "<doctest test.test_syntax[49]>", line 1
 SyntaxError: keyword argument repeated
 
+>>> del ()
+Traceback (most recent call last):
+   ...
+  File "<doctest test.test_syntax[50]>", line 1
+SyntaxError: can't delete ()
+
 """
 
 import re
diff --git a/Python/ast.c b/Python/ast.c
index a415495..4a85164 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -402,10 +402,13 @@ set_context(struct compiling *c, expr_ty e, expr_context_ty ctx, const node *n)
             s = e->v.List.elts;
             break;
         case Tuple_kind:
-            if (asdl_seq_LEN(e->v.Tuple.elts) == 0) 
-                return ast_error(n, "can't assign to ()");
-            e->v.Tuple.ctx = ctx;
-            s = e->v.Tuple.elts;
+            if (asdl_seq_LEN(e->v.Tuple.elts))  {
+                e->v.Tuple.ctx = ctx;
+                s = e->v.Tuple.elts;
+            }
+            else {
+                expr_name = "()";
+            }
             break;
         case Lambda_kind:
             expr_name = "lambda";