What is an example of using __new__ in Python such that within the body of __new__ you do not return the result of calling some other (base, meta, or otherwise) class's version of __new__, but you do return an allocated instance of the intended class so that __init__ will be invoked?
I'm guessing this is (and should be) very rare, but I'm curious if there is an example of this use case. I tried searching around for the Python source of tuple's implementation of __new__ and also for type's implementation, but it did not seem like this is quick and easy to find online.
You can't, that's not something you can do on the Python side of things. A no-op __new__ method would call object.__new__(cls), which returns a bare instance of class cls.
>>> class A:
... def __new__(cls):
... return object.__new__(cls)
...
>>> A()
<__main__.A object at 0x7f9e951577d0>