A follow up for issue #15906: change the test for calling the type conversion
on the action's default, reverting it back to previous behavior. Conversion
is only done on string defaults.
Add a test for this and another test that ensures such type conversions are
only called once.
diff --git a/Lib/argparse.py b/Lib/argparse.py
index fba6a26..e2677f8 100644
--- a/Lib/argparse.py
+++ b/Lib/argparse.py
@@ -1957,7 +1957,7 @@
# twice (which may fail) if the argument was given, but
# only if it was defined already in the namespace
if (action.default is not None and
- isinstance(action, _StoreAction) and
+ isinstance(action.default, basestring) and
hasattr(namespace, action.dest) and
action.default is getattr(namespace, action.dest)):
setattr(namespace, action.dest,
diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py
index cd80dc6..22c26cc 100644
--- a/Lib/test/test_argparse.py
+++ b/Lib/test/test_argparse.py
@@ -4500,11 +4500,11 @@
args = parser.parse_args('--foo spam!'.split())
self.assertEqual(NS(foo='foo_converted'), args)
-# ================================================================
-# Check that the type function is called with a non-string default
-# ================================================================
+# ==================================================================
+# Check semantics regarding the default argument and type conversion
+# ==================================================================
-class TestTypeFunctionCallWithNonStringDefault(TestCase):
+class TestTypeFunctionCalledOnDefault(TestCase):
def test_type_function_call_with_non_string_default(self):
def spam(int_to_convert):
@@ -4514,8 +4514,31 @@
parser = argparse.ArgumentParser()
parser.add_argument('--foo', type=spam, default=0)
args = parser.parse_args([])
+ # foo should *not* be converted because its default is not a string.
+ self.assertEqual(NS(foo=0), args)
+
+ def test_type_function_call_with_string_default(self):
+ def spam(int_to_convert):
+ return 'foo_converted'
+
+ parser = argparse.ArgumentParser()
+ parser.add_argument('--foo', type=spam, default='0')
+ args = parser.parse_args([])
+ # foo is converted because its default is a string.
self.assertEqual(NS(foo='foo_converted'), args)
+ def test_no_double_type_conversion_of_default(self):
+ def extend(str_to_convert):
+ return str_to_convert + '*'
+
+ parser = argparse.ArgumentParser()
+ parser.add_argument('--test', type=extend, default='*')
+ args = parser.parse_args([])
+ # The test argument will be two stars, one coming from the default
+ # value and one coming from the type conversion being called exactly
+ # once.
+ self.assertEqual(NS(test='**'), args)
+
def test_issue_15906(self):
# Issue #15906: When action='append', type=str, default=[] are
# providing, the dest value was the string representation "[]" when it