swapping numbers in python

Question

using bitwise operator (xor),
a = a ^ b
b = b ^ a
a = a ^ b
will swap the numbers

is a one liner not possible?
like: a ^= b ^= a ^= b

I tried, but got some error

reference:
https://code.sololearn.com/c26o4pSfqFJL/?ref=app

Answer 1

Harsha S
1. a,b=b,a 👍
2. 😵 a,b=a^b^a,b^a^b 😲
3. 😵 a^=b^(b:=b^a^b) 😲

Answer 2

I presume you already know that swapping in Python is hassle free assignment with the RHS expression position flipped

a, b = b, a

So why go through the bitwise hassle?

Answer 3

Harsha S
You can do the bitwise trick with walrus operator

(a := (b := (a := b ^ a) ^ b) ^ a)

https://code.sololearn.com/cHUjIao4hGKY/?ref=app

https://realpython.com/JUMP_LINK__&&__python__&&__JUMP_LINK-walrus-operator/

Answer 4

Ipang yeah, i know that. I was just trying to explore various other methods of swapping.

Answer 5

Harsha S, you ask the question:
"Is one liner impossible?
for example: a ^= b ^= a ^= b".

And then you give an example of properly working code with the same line.
So what's the problem?

Answer 6

Solo by "correct" what do you mean is correct?
the code i linked has the one-liner bitwise operation to swap two variables.

Answer 7

a,b =b,a

Answer 8

Solo the code i have given is in c++
I want to implement it in python