@deprecated breaking __init__ inheritance when used with mixins/multiple inheritance about typing_extensions

[ljluestc]

from typing_extensions import deprecated

class Service:
def init(self, foo: str, bar: str) -> None:
print("Service.init")
self.foo = foo
self.bar = bar

def echo(self) -> None:
    print("Service.echo", self.foo, self.bar)

class Base:
def message(self) -> None:
print("Base.message")

class Child(Base):
def message(self) -> None:
print("Child.message")
super().message()

@deprecated("Use Child instead") # removing this will work normally
class FooBarPrinter(Child):
pass

class Spam(Service, FooBarPrinter):
def init(self, foo: str, bar: str) -> None:
super().init(foo, bar) # Call the constructor of FooBarPrinter or use Base.init(self)

def do_work(self):
    self.echo()
    self.message()

if name == "main":
Spam("foo", "bar").do_work()

[JelleZijlstra]

Thanks for the report (and sorry for the slow response).

@deprecated's patching of classes is a bit fragile and in some cases, the best solution may be to pass category=None and disable the runtime DeprecationWarning. However, for this case I found a solution; PR incoming.