T8445: add falsy callable

This is useful as default value for a getattr of a function from a
module.

1 files changed, 28 insertions, 0 deletions

diff --git a/python/vyos/utils/func.py b/python/vyos/utils/func.py
new file mode 100644
index 000000000..830b76c94
--- /dev/null
+++ b/python/vyos/utils/func.py
@@ -0,0 +1,28 @@
+# Copyright (C) VyOS Inc.
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+
+
+"""Module for functors and higher order functions."""
+
+
+class FalseCallable:
+    """Define falsy callable for use as default value for getattr of a
+    function from a module defined by vyos.utils.system.load_as_module"""
+
+    def __call__(self, *args, **kwargs):
+        pass
+
+    def __bool__(self):
+        return False