[Tutor] why can you swap an immutable tuple?

[Jim Mooney]

On 25 May 2013 19:38, Steven D'Aprano <steve at pearwood.info> wrote:

> On 26/05/13 05:23, Mark Lawrence wrote:
>


> On the right hand side, 5,8 creates a tuple, which is then immediately
> unpacked to two individual values. You can see this by disassembling the
> code. In 2.7, you get this:
>
> py> from dis import dis
> py> code = compile("a, b = 5, 8", "", "exec")
> py> dis(code)
>   1           0 LOAD_CONST               3 ((5, 8))
>               3 UNPACK_SEQUENCE          2
>               6 STORE_NAME               0 (a)
>               9 STORE_NAME               1 (b)
>              12 LOAD_CONST               2 (None)
>              15 RETURN_VALUE
>
> That disassembling looks like it could clarify a number of things. I'll
have to try it. It might make more sense to me since my  only programming,
besides a bit of javascript copy-hacking for websites, was A86 Assembler,
some decades ago, when I wrote an ASCII Art prog for Fidonet.

Then I got into other fields entirely to make a living. But Asm actually
makes sense to me and the disassemble looks close to it. (I can't count the
times I wiped out DOS and had to reload it ;')  A86 had a wonderful macro
language, though.

Jim
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