#15847: allow args to be a tuple in parse_args
This fixes a regression introduced by the fix for issue #13922. Although args
is not documented as being allowed to be a tuple, previously this worked and
so naturally there are programs in the field that depend on it.
Patch by Zbyszek Jędrzejewski-Szmek.
diff --git a/Lib/argparse.py b/Lib/argparse.py
index a738455..ab8ff2f 100644
--- a/Lib/argparse.py
+++ b/Lib/argparse.py
@@ -1692,9 +1692,12 @@
return args
def parse_known_args(self, args=None, namespace=None):
- # args default to the system args
if args is None:
+ # args default to the system args
args = _sys.argv[1:]
+ else:
+ # make sure that args are mutable
+ args = list(args)
# default Namespace built from parser defaults
if namespace is None:
diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py
index 77f5aca..99c1bab 100644
--- a/Lib/test/test_argparse.py
+++ b/Lib/test/test_argparse.py
@@ -4486,6 +4486,24 @@
class TestParseKnownArgs(TestCase):
+ def test_arguments_tuple(self):
+ parser = argparse.ArgumentParser()
+ parser.parse_args(())
+
+ def test_arguments_list(self):
+ parser = argparse.ArgumentParser()
+ parser.parse_args([])
+
+ def test_arguments_tuple_positional(self):
+ parser = argparse.ArgumentParser()
+ parser.add_argument('x')
+ parser.parse_args(('x',))
+
+ def test_arguments_list_positional(self):
+ parser = argparse.ArgumentParser()
+ parser.add_argument('x')
+ parser.parse_args(['x'])
+
def test_optionals(self):
parser = argparse.ArgumentParser()
parser.add_argument('--foo')