Can tuple be considered both as mutable and immutable based on content

Question

I was going through python language reference and I came across following:

when we talk about the mutability of a container, only the identities of the immediately contained objects are implied. So, if an immutable container (like a tuple) contains a reference to a mutable object, its value changes if that mutable object is changed.

Am I correct in thinking that tuple can be considered both as mutable and immutable based the things it contains? For example if a tuple contains only strings then it can be immutable and if it contains at least one mutable reference like list then the tuple is itself mutable as.

Answer 1

All a tuple does is contain a fixed list of references. Those references cannot be changed, and so this makes a tuple immutable. Whether the referenced objects are mutable is another story, but that's beyond the scope of tuple, so it would not be accurate to say a tuple can be mutable if it references mutable objects.

Answer 2

That's not usually the way it's conceptualized. The tuple is always immutable; the objects it contains may or may not be mutable. Similarly, if you have a fireproof box, and you put paper inside it, the box is still fireproof, even though the paper is not (and thus the entire box-paper combo could be considered non-fireproof).

Answer 3

Am I correct in thinking that tuple can be both mutable and immutable based the things it contains?

Consider the fact, that, tuples contains a fixed sized objects with definite identifiers. None of these objects can be replaced with a different object. But this does not mean the object's content cannot change.

Technically speaking if

T = (O₁, O₂, O₃ .. O_n), where O₁ through O_n are certain objects and through out the lifetime of the tuple T, you cannot replace one or more of these objects O_i with some other objects O_j where i <> j. But O_i can mutate.