given a string:
st="abcdatraataza" ^ ^ ^ ^ (these should be found) I want to get the positions of all single 'a' characters. (Without another 'a' neighbour)
You could also try negative lookahead/lookbehind assertions:
>>> st="abcdatraataza" >>> for m in re.finditer("(?<!a)a(?!a)", st): ... print m.start() ... 0 4 10 12
Steve -- http://mail.python.org/mailman/listinfo/python-list