Guilty secret: globals baffle me

[Gonçalo Rodrigues]

On 6 Nov 2002 17:21:46 GMT, bokr at oz.net (Bengt Richter) wrote:

>I have an uncomfortable feeling there is unfinished
>business in the way names in nested scopes and otherwise
>related namespaces work. The global/local dichotomy doesn't
>fully express the possibilities any more. IMO it would be nice
>to have full access to accessible namespaces without magically
>determined access mode restrictions based on full-function lookahead.
>
>I.e., we have a de facto hierarchy of name spaces defined by the
>ability to nest functions. Why not have an access mechanism that
>allows rebinding as desired? E.g., you could let locals take a depth argument,
>so locals() is equivalent to locals(0), and locals(1) is the enclosing
>name space, so locals(1)['x'] = 3 in bar above would rebind the x local to foo.
>

I totally agree with you. The uncomfortable feeling is underlined by the
fact that you can rebind global names through the use of global (the
only declaration in Python - ach!) but not names in the enclosing scope
- if it is not global that is. Although I do not feel that there is a
need for this feature in Python, it strikes as an ugly asymmetry - the
ugliest in fact.

I would just change a little bit your notation. Instead of reusing
locals use something like

enclosed()

returning the enclosing scope. And you've guessed it - if you want to
get at the next scope just use enclosed().enclosed(). The enclosed() at
global scope should return None.

Now if you wanted to rebind a variable in the enclosing scope you should
be able to use the notation

enclosed().x = <whatever>

and not dict notation. globals() should follow the same rules.

With my best regards,
Gonçalo Rodrigues