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Regular Expression Question

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In article <3aca5b94_2 at news.nwlink.com>,Wesley Witt <wesw at wittfamily.com> wrote:>This is probably a simple question, but I can't seem to find the answer>anywhere.>>I want a regular expression that will match ALL lines that do NOT contain>the string "skip".  I have some backup logs that I need to filter the noise>out of.Don't do this.  Your successor maintainers will curse you, your bosswill fire you, and your dog will pee on you.Just say:for line in file.getlines():    if string.find(line, 'skip') == -1:         outfile.write(line)But if you're curious:You can match a line not containing 's' simply: re.compile("^[^s]*$").You can match a line not containing 'sk' with more difficulty:re.compile("^([^s]|s+[^sk])*$")'ski' is a little harder; I think there's an easier way to do this, butI don't know what it is:re.compile("^([^s]|(s(ks)*)+([^sk]|k[^is]))*$")(I think there's an easier way because the above RE is not strictlydeterministic --- it has to push two states when it sees 'sk', onefor k's followed by s and one followed by [^is].)All of these REs have a bug: if a prefix of the evil sequence occurs atthe end of a line, they fail.  I'm not sure how to fix that, and Idon't want to extend it to 'skip'.-- <kragen at pobox.com>       Kragen Sitaker     <http://www.pobox.com/~kragen/>Perilous to all of us are the devices of an art deeper than we possessourselves.       -- Gandalf the White [J.R.R. Tolkien, "The Two Towers", Bk 3, Ch. XI]

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