[Tutor] Fibonacci Series

[Dave Angel]

On Sun, 24 Nov 2013 11:24:43 +0100, Rafael Knuth 
<rafael.knuth at gmail.com> wrote:
>     a, b = b, a +b


> a = b = 1
> b = a + b = 1 + 1 = 2

I suggest you play with the statement a bit. Print out both values 
each time through the loop.

The expression b, a+b produces a tuple. The left side a, b *unpacks* 
that tuple into the two variables.a and b.

Perhaps a simpler case might help. Try a, b = b, a   What would you 
expect it to do and why?

-- 
DaveA