Stepping backwards in for loop?

[Steve Purcell]

Gustaf Liljegren wrote:
> Can't figure out how to step backwards, character by character in a string. 
> I was looking for a loop countruct with a counter to handle this, but the 
> for loop in Python doesn't let me step backwards. What is the alternative?

An alternative is to use a forward loops but use negative indexes for the
string, which go from -1 to (-1 - len(s)):

    >>> s = "forwards"
    >>> backwards = []
    >>> for i in range(1, 1+len(s)):
    ...   backwards.append(s[-i])
    ... 
    >>> backwards
    ['s', 'd', 'r', 'a', 'w', 'r', 'o', 'f']
    >>> 

-Steve

-- 
Steve Purcell, Pythangelist
Get testing at http://pyunit.sourceforge.net/
Any opinions expressed herein are my own and not necessarily those of Yahoo