Why does Python swaps variable ids when swaps variables

Question

I thought every object take an id based on key.

>>> a = 10
>>> b = 20
>>> id(a)
1876869280
>>> id(b)
1876869440
>>> a,b=b,a
>>> id(a)
1876869440
>>> id(b)
1876869280

When swap the variables, their ids are swapped too. If every object has a unique id, then why ids are swapped? I thought id(a) and id(b) will be same after swap.

What Ignacio said. You may find it helpful to read this article, written by SO member Ned Batchelder: Facts and myths about Python names and values. — PM 2Ring
– PM 2Ring, Commented Feb 11, 2015 at 3:28

Ignacio Vazquez-Abrams · Accepted Answer · 2015-02-11 03:20:04Z

6

If every object has a unique id, then why ids are swapped?

Because you swapped objects. The objects aren't a and b, they're 10 and 20. a and b are just names that the code uses to refer to those objects.

answered Feb 11, 2015 at 3:20

Ignacio Vazquez-Abrams

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