Stepping backwards in for loop?
Steve Purcell
stephen_purcell at yahoo.com
Sat Apr 14 10:49:25 EDT 2001
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
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