Steve Nelson wrote:
>> x, y = y, x
>
> Doesn't this use temporary variables?
Yes, behind the scenes maybe it does. It may create a temporary list,
then unpack it - that is what the syntax actually means. Let's take a look:
In [1]: import dis
In [2]: def f(x, y):
...: x, y = y, x
..
On 1/30/07, Steve Nelson <[EMAIL PROTECTED]> wrote:
> > x, y = y, x
>
> Doesn't this use temporary variables?
Python doesn't really *have* variables, as such, so no. What it does
is to create a tuple referring to the objects (or just possibly one
object) referred to by the names 'y' and 'x', then
On 1/29/07, Kent Johnson <[EMAIL PROTECTED]> wrote:
> Because 2 ^ 3 == 1, right? Are you sure you understand what xor does? It
> is a bitwise exclusive or:
Yes... at a binary level, it returns true if either input is true, but not both:
A B Q
0 0 0
0 1 1
1 0 1
1 1 0
Thus it has the effect of swa
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
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
S.
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