Scoping Issues

[Chris Rebert]

On Thu, May 24, 2012 at 6:23 PM, SherjilOzair <sherjilozair at gmail.com> wrote:
> def adder():
>        s = 0
>        def a(x):

Add a "nonlocal s" declaration right here.
See http://www.python.org/dev/peps/pep-3104/

>            s += x
>            return sum
>        return a
>
> pos, neg = adder(), adder()
> for i in range(10):
>        print pos(i), neg(-2*i)
>
> This should work, right? Why does it not?

Python doesn't have a C-like variable declaration scheme. So without a
`global` or `nonlocal` declaration, you can only assign to names which
reside in the innermost scope.

> Checkout slide no. 37 of a Tour of Go to know inspiration.

You mean slide #38 ("And functions are full closures.").

> Just wanted to see if python was the same as Go in this regard. Sorry, if I'm being rude, or anything.

I would suggest reading through the Python Language Reference
(http://docs.python.org/release/3.1.5/reference/index.html ) prior to
asking further questions, as it may well answer them for you.

Cheers,
Chris