A minor headache for a beginner coder (lemmy.dbzer0.com)

submitted 3 weeks ago by moosetwin@lemmy.dbzer0.com to c/python@programming.dev

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if var1 equals 1, and you run var2 = var1, that sets var2 to 1.

if list1 equals [1, 2, 3], and you run list2 = list1, that sets list2 to list1

so if you then run var1 = 2, var2 will still be 1

but if you run list1 = [3, 2, 1], list2 will give [3, 2, 1]

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[-] marcos@lemmy.world 2 points 3 weeks ago

As I said, it's because you can't change the value of a primitive value. (That is, unless you abuse the C interface.)

Because Python doesn't protect classes, you just can't do the same with the types you create. But that's what is special, not the way if handles variables.

And this is different from languages like Java/C#, PHP/Perl, etc. Most imperative languages have primitive atomic values that go directly into your variables. But Python has only references (except for some complicated optimizations). Anyway, it is weird, and it's one of the reasons people should learn C or Rust eventually.