#4617: Previously it was illegal to delete a name from the local
namespace if it occurs as a free variable in a nested block. This limitation
of the compiler has been lifted, and a new opcode introduced (DELETE_DEREF).
This sample was valid in 2.6, but fails to compile in 3.x without this change::
>>> def f():
... def print_error():
... print(e)
... try:
... something
... except Exception as e:
... print_error()
... # implicit "del e" here
This sample has always been invalid in Python, and now works::
>>> def outer(x):
... def inner():
... return x
... inner()
... del x
There is no need to bump the PYC magic number: the new opcode is used
for code that did not compile before.
diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py
index 126a57f..e2824b2 100644
--- a/Lib/test/test_exceptions.py
+++ b/Lib/test/test_exceptions.py
@@ -526,6 +526,17 @@
obj = wr()
self.assertTrue(obj is None, "%s" % obj)
+ def test_exception_target_in_nested_scope(self):
+ # issue 4617: This used to raise a SyntaxError
+ # "can not delete variable 'e' referenced in nested scope"
+ def print_error():
+ e
+ try:
+ something
+ except Exception as e:
+ print_error()
+ # implicit "del e" here
+
def test_generator_leaking(self):
# Test that generator exception state doesn't leak into the calling
# frame