unreferenced (???) variable; prob. simple

[Halfdan Holger Knudsen]

goodday all - here's a snippet of code that just doesn't seem to work...at
all! But I haven't got the faintest idea why I keep getting an unref.
local var. error. Take a look - I know I can get good help here. And PS:
Thanks beforehand. 

If you're wondering - it's an attempt at a (crude) reproduction of the string.split() functionality for learning purposes.

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#! /usr/bin/env python

import string
begind = 0
endind = 0

def stripfunc():
    inpstr = raw_input('String to strip: ')
    length = len(inpstr)
    spacelst = list(string.whitespace)
    print spacelst
    for a in range(length):
        if inpstr[a] not in spacelst:
            begind = a
            break
        break
    for b in range(1, length+1):
        if inpstr[-b] not in spacelst:
            endind = length-b
            break
        break
    stripstring = inpstr[begind:(endind+1)]
    print stripstring
    print begind
    print endind

if __name__ == '__main__':
    stripfunc()