I looked at the code again to make sure I wasn't speaking out of turn and it basically works like this: >>> import re >>> pattern='(\\\\|/|\s+|;|-)' >>> testdata='this-is-a-test.txt' >>> matches=re.split(pattern, testdata) >>> matches ['this', '-', 'is', '-', 'a', '-', 'test.txt'] >>> pattern='(\\\\)' >>> testdata='this-is-a-test.txt' >>> matches=re.split(pattern, testdata) >>> matches ['this-is-a-test.txt'] The delims value is just a splitter, not a filtering mechanism despite the bad variable naming I used in the script. I'll have to rename that later on... At any rate, modifying the delims to not include the hyphen should solve your issue. ... View more