Hlelp clean up clumpsy code

[Steven Bethard]

It's me wrote:
> Another newbie question.
> 
> There must be a cleaner way to do this in Python:
> 
> #### section of C looking Python code ####
> a = [[1,5,2], 8, 4]
> a_list = {}
> i = 0
> for x in a:
>     if isinstance(x, (int, long)):
>         x = [x,]
>     for w in [y for y in x]:
>         i = i + 1
>         a_list[w] = i
> print a_list
> #####
> 
> The code prints what I want but it looks so "C-like".  How can I make it
> more Python like?

Don't know what version of Python you're using, but if you're using 2.4 
(or with a few slight modifications, with 2.3), you can write:

py> dict((item, i+1)
...      for i, item in enumerate(
...          a_sub_item
...          for a_item in a
...          for a_sub_item
...          in isinstance(a_item, (int, long)) and [a_item] or a_item))
{8: 4, 1: 1, 2: 3, 4: 5, 5: 2}

Basically, I use a generator expression to flatten your list, and then 
use enumerate to count the indices instead of keeping the i variable.

Steve