> Used to see many flaws in the language (things like `.append` changing the object, returning `None` instead of creating a copy and returning that) I think it

> Used to see many flaws in the language (things like `.append` changing the object, returning `None` instead of creating a copy and returning that) I think it's pretty off-base to call this a "flaw". Immutable structures have their place and can be very helpful where appropriate, but making its core primitives work this way is far outside the scope or the philosophy of Python. If you want otherwise, you're really wanting an entirely different language. And there's nothing wrong with that! But I think it would be a "flaw" for Python to make these operations immutable, even though I love immutability personally.