Bug #1520864 (again): unpacking singleton tuples in list comprehensions and
generator expressions (x for x, in ... ) works again.
Sigh, I only fixed for loops the first time, not list comps and genexprs too.
I couldn't find any more unpacking cases where there is a similar bug lurking.
This code should be refactored to eliminate the duplication. I'm sure
the listcomp/genexpr code can be refactored. I'm not sure if the for loop
can re-use any of the same code though.
Will backport to 2.5 (the only place it matters).
diff --git a/Lib/test/test_grammar.py b/Lib/test/test_grammar.py
index f160867..c39e416 100644
--- a/Lib/test/test_grammar.py
+++ b/Lib/test/test_grammar.py
@@ -825,6 +825,10 @@
verify([ x for x in range(10) if x % 2 if x % 3 ], [1, 5, 7])
verify((x for x in range(10) if x % 2 if x % 3), [1, 5, 7])
+# Verify unpacking single element tuples in listcomp/genexp.
+vereq([x for x, in [(4,), (5,), (6,)]], [4, 5, 6])
+vereq(list(x for x, in [(7,), (8,), (9,)]), [7, 8, 9])
+
# Test ifelse expressions in various cases
def _checkeval(msg, ret):
"helper to check that evaluation of expressions is done correctly"