bpo-40334: Produce better error messages for non-parenthesized genexps (GH-20153)
The error message, generated for a non-parenthesized generator expression
in function calls, was still the generic `invalid syntax`, when the generator expression wasn't appearing as the first argument in the call. With this patch, even on input like `f(a, b, c for c in d, e)`, the correct error message gets produced.
diff --git a/Lib/test/test_syntax.py b/Lib/test/test_syntax.py
index 6d9c4e4..4df5535 100644
--- a/Lib/test/test_syntax.py
+++ b/Lib/test/test_syntax.py
@@ -216,11 +216,9 @@
>>> f(x for x in L, **{})
Traceback (most recent call last):
SyntaxError: Generator expression must be parenthesized
-
-# >>> f(L, x for x in L)
-# Traceback (most recent call last):
-# SyntaxError: Generator expression must be parenthesized
-
+>>> f(L, x for x in L)
+Traceback (most recent call last):
+SyntaxError: Generator expression must be parenthesized
>>> f(x for x in L, y for y in L)
Traceback (most recent call last):
SyntaxError: Generator expression must be parenthesized