Sorting dict keys

[Will Maier]

On Fri, Jul 20, 2007 at 03:27:51PM -0700, montyphyton at gmail.com wrote:
> Consider the following:
> >>> a = {1:2, 3:4, 2:5}
> 
> Say that i want to get the keys of a, sorted. First thing I  tried:
> 
> >>> b = a.keys().sort()
> >>> print b
> None

list's sort() method sorts the list _in_place_:

    >>> l = ['spam', 'eggs']
    >>> help(l.sort)
    Help on built-in function sort:

    sort(...)
        L.sort(cmp=None, key=None, reverse=False) -- stable sort *IN PLACE*;
        cmp(x, y) -> -1, 0, 1

That means that doesn't return a sorted version of the list you're
working with. Instead, it sorts the list itself.

If you want to return a sorted list, use (duh) sorted:

    >>> sorted(l)
    ['eggs', 'spam', 'spam']

-- 

[Will Maier]-----------------[willmaier at ml1.net|http://www.lfod.us/]