[Tutor] Variables don't change when altered within a loop?

[Bob Gailer]

Evan Klitzke wrote:
> Hi, I just started picking up python yesterday, and have already come
> across something that has me stumped.  I want some code that does
> this:
>
> a = foo(a)
> b = foo(b)
> c = foo(c)
>
> So I try to do this with a for loop, like so:
>
> for i in [a, b, c]:
>    i = foo(i)
>    print i     # make sure that it worked correctly
>
> So far, so good.  The problem is that outside the loop, the values
> aren't changed.  For example,
>
> print [a, b, c]   # outside the loop; the values never actually changed!
>
> What is going on?  Why aren't the values of my variables changing when
> I change them inside a loop like this?
>   
The program is not changing a or b or c in the loop. The for statement 
assigns a to i. The next statement assigns a new value to i. a is not 
affected. Change print i to print i, a, b, c # and note that a, b, c are 
unchanged.

-- 
Bob Gailer
510-978-4454