bpo-40389: Improve repr of typing.Optional (#19714)
diff --git a/Lib/typing.py b/Lib/typing.py
index c829898..f3cd280 100644
--- a/Lib/typing.py
+++ b/Lib/typing.py
@@ -691,6 +691,13 @@
return _GenericAlias(self.__origin__, params, name=self._name, inst=self._inst)
def __repr__(self):
+ if (self.__origin__ == Union and len(self.__args__) == 2
+ and type(None) in self.__args__):
+ if self.__args__[0] is not type(None):
+ arg = self.__args__[0]
+ else:
+ arg = self.__args__[1]
+ return (f'typing.Optional[{_type_repr(arg)}]')
if (self._name != 'Callable' or
len(self.__args__) == 2 and self.__args__[0] is Ellipsis):
if self._name: