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Comment by random_upvoter | Hacker News Reader

For me it's somewhat strange that it is universally presented as a beginner's language. Python would be hugely confusing to me if I didn't keep the underlying C model -- dynamically allocated objects with reference counts -- in mind at all time. Together with a lot of protocol that is largely arbitrary.

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I've met a lot of people who have programmed simple things in python without understanding the memory model at all so for most people it doesn't seem to be a large impediment.

Would you also find Excel macros hugely confusing if you didn't know the underlying C model? Because I think that's the level of programming that the masses are doing.

To me that would only be relevant if I'm doing super performance sensitive stuff, and if that's the case I wouldn't be using Python.

I've been programming in both C and Python for years and never once have I had to consider reference counting in Python.

When teaching Python to beginners, I struggle with the concept of mutability -- e.g. `sorted(mylist) vs mylist.sort()` without being able to refer to the concepts of memory and references. But it's not a terrible obstacle if you drill in extra adherence to logic and testing and jumping into REPL. After enough trial-and-error with `x is y` `x == y` and `id(x)`, the abstract concept comes through without having to acknowledge the existence of reference count.

Hardly a beginner at programming, but I also struggled with this when I picked up Python recently. The documentation doesn't make it obvious when functions have this sort of side effect, so like your students I play with the REPL to establish exactly what a function will do. Even then an unexpected side effect was the source of the single most perplexing bug in my program. I imagine that in complex programs this philosophy of sometimes-mutability-sometimes-not must lie at the root of a huge amount of programming error.

Can you provide an example of why you need to understand the underlying C model?

I don't think I've ever considered it when writing a Python program.

In all this time I didn’t even know python uses reference counting instead of tracing gc...

It also uses mark-and-sweep.

    a = []
    a.append(a)

Can't collect that one with ref counting.

Weird. :)

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