bpo-36517: Raise error on multiple inheritance with NamedTuple (GH-19363)
diff --git a/Lib/typing.py b/Lib/typing.py
index 5351883..99355d0 100644
--- a/Lib/typing.py
+++ b/Lib/typing.py
@@ -1728,6 +1728,9 @@
def __new__(cls, typename, bases, ns):
if ns.get('_root', False):
return super().__new__(cls, typename, bases, ns)
+ if len(bases) > 1:
+ raise TypeError("Multiple inheritance with NamedTuple is not supported")
+ assert bases[0] is NamedTuple
types = ns.get('__annotations__', {})
nm_tpl = _make_nmtuple(typename, types.items())
defaults = []