From: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com>
Date: Sat, 6 Jun 2020 02:31:18 +0000 (-0700)
Subject: bpo-40862: Raise TypeError when const is given to argparse.BooleanOptionalAction... 
X-Git-Tag: v3.9.0b2~21
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=d5e7348e4105d1d4a1c5bd1087f61041532ecbf3;p=thirdparty%2FPython%2Fcpython.git

bpo-40862: Raise TypeError when const is given to argparse.BooleanOptionalAction (GH-20623) (GH-20664)
---

diff --git a/Lib/argparse.py b/Lib/argparse.py
index 2677ef63e9e5..2fb1da59f942 100644
--- a/Lib/argparse.py
+++ b/Lib/argparse.py
@@ -857,7 +857,6 @@ class BooleanOptionalAction(Action):
     def __init__(self,
                  option_strings,
                  dest,
-                 const=None,
                  default=None,
                  type=None,
                  choices=None,
diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py
index e82a0c39c21a..22cae626ccc2 100644
--- a/Lib/test/test_argparse.py
+++ b/Lib/test/test_argparse.py
@@ -700,6 +700,14 @@ class TestBooleanOptionalAction(ParserTestCase):
         ('--no-foo --foo', NS(foo=True)),
     ]
 
+    def test_const(self):
+        # See bpo-40862
+        parser = argparse.ArgumentParser()
+        with self.assertRaises(TypeError) as cm:
+            parser.add_argument('--foo', const=True, action=argparse.BooleanOptionalAction)
+
+        self.assertIn("got an unexpected keyword argument 'const'", str(cm.exception))
+
 class TestBooleanOptionalActionRequired(ParserTestCase):
     """Tests BooleanOptionalAction required"""