[Tutor] Variable Swap

[Kent Johnson]

Steve Nelson wrote:
> Hello,
> 
> I understand the use of xor to do a variable swap without a temporary variable:
> 
>>>> x=2
>>>> y=3
>>>> y=x^y
>>>> x=x^y
>>>> y=x^y
>>>> x
> 3
>>>> y
> 2
> 
> 
> However, why do I see this?
> 
>>>> y=x^y
>>>> y
> 1

Because 2 ^ 3 == 1, right? Are you sure you understand what xor does? It 
is a bitwise exclusive or:
http://en.wikipedia.org/wiki/Xor#Bitwise_operation

By the way in Python you can write
x, y = y, x
as a readable alternative.

Kent