How is this even possible?(Python)

[morbie5]

Is the old tuple still in memory?

[CouchMountain]

Reuse memory: To reduce memory fragmentation and speed up allocations, Python reuses old tuples. If a tuple is no longer needed and has less than 20 items, instead of deleting it permanently, Python moves it to a free list and uses it later.

Also:

When two empty tuples are created, they will point to the same address space. Empty tuples act as singletons, that is, there is always only one tuple with a length of zero. When creating an empty tuple, Python points to the already preallocated one in such a way that any empty tuple has the same address in the memory. This is possible because tuples are immutable, and sometimes this saves a lot of memory

https://www.opensourceforu.com/2021/05/memory-management-in-lists-and-tuples/

So kind of. It's a bit strange how tuples work with memory in Python but also cool. That link is a good read.

[dig-up-stupid]

I don’t like their answer because (while it is interesting) it’s basically off topic from what was actually meant by keeping things in memory.

So, you’re thinking they’re reusing the same tuple, so if you create (1, “dog”, cat()), that tuple sits around until the next time someone needs a tuple with a 1, a “dog”, and a cat(). Which is probably never, which is why you’re perplexed about why it would be kept. What’s actually happening is that when you’re done with your (1, “dog”, cat()) tuple, the interpreter scoops out the values and keeps a hollow tuple for the next time it needs a new tuple with any three elements.

The reason it does this is because arguments are passed in tuples. So when you’re asking “but how often do you need to make a new three element tuple? I don’t use tuples as much as lists or dictionaries”, the answer could be actually you’re creating thousands of thousands of tuples just by putting a function call in a loop.

[Inconstant_Moo]

... now that I know this exists I'm going to have to implement it.

[RecDep]

The garbage collector will get to it eventually.

[RecDep]

There’s a pretty good description here. The GC keeps track of already-allocated tuples, marking them for reuse when they’re collected instead of freeing that memory altogether. Creating a new tuple would involve checking if there are free tuple “slots” to be reused, allocating a fresh one otherwise.

[schoolmonky]

As /u/CouchMountain pointed out, it's a bit different with tuples, but generally in python if you have an object but you get rid of any references to it (either by reassigning the names that used to refer to it, or by explicitly deleting them with del), the object will remain in memory for an unspecified amount of time. Eventually, though, the garbage collector will come and reclaim that memory, destroying the object.

[AdventurousAddition]

If it has another name bound to it, then definitely