how to iterate over sequence and non-sequence ?

[stef mientki]

Steven D'Aprano wrote:
> On Fri, 19 Oct 2007 16:19:32 +0200, stef wrote:
>
>   
>> Well I'm not collecting data, I'm collecting pointers to data.
>>     
>
> I beg to differ, you're collecting data. How that data is to be 
> interpreted (a string, a number, a pointer...) is a separate issue.
>
>
>   
>> This
>> program simulates a user written program in JAL. As Python doesn't
>> support pointers, instead I collect names.
>>     
>
> This doesn't make any sense to me. If your user-written program is 
> supplying pointers (that is, memory addresses like 0x15A8), how do you 
> get a name from the memory address?
>
>
> If you are trying to emulate pointer-manipulation, then the usual way to 
> simulate a pointer is with an integer offset into an array:
>
> # initialise your memory space to all zeroes:
> memory = [chr(0)]*1024*64  # 64K of memory space, enough for anyone
> NULL = 0
> pointer = 45
> memory[pointer:pointer + 5] = 'HELLO'
> pointer += 6
> memory[pointer:pointer + 5] = 'WORLD'
>
>
>   
If there is a better way, I'ld like to hear it.
I understand that execute is dangerous.

I don't have pointers, I've just names (at least I think).
Let me explain a little bit more,
I want to simulate / debug a user program,
the user program might look like this:

   x = 5
   for i in xrange(10):
       x = x + 1

So now I want to follow the changes in "x" and "i",
therefor in the background I change the user program a little bit, like 
this

def user_program():
   x = 5    ; _debug(2)
   global x,i
   _debug (3)
   for i in xrange(10):
       _debug (3)
       x = x + 1    ; _debug (4)

And this modified user program is now called by the main program.
Now in the _debug procedure I can set breakpoints and watch x and i.
But as in this case both a and i are simple integers,
I can not reference them and I need to get their values through their 
names,
and thus a execute statement.

I couldn't come up with a better solution ;-)
(There may be no restrictions laid upon the user program, and indeed 
name clashing is an accepted risk).

cheers,
Stef