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Question/Bug: how do I preserve dashes and not replace them with separator? #107
Description
I am trying to slugify a string, replacing non-matching characters with an underscore, but I don't want to consider a dash a non-matching character. This is easily achieved with regex but it looks like there is some special slugify behaviour when it comes to dashes which is preventing this working. I can't see anything in the docs or code, about how to work around this.
What did I do?
slugify.slugify("test-foo bar", separator='_', regex_pattern=r'[^-a-zA-Z0-9_]+')What happened?
test_foo_bar
What did I expect?
test-foo_bar
Activity
adamcunnington-mlg commentedon Nov 1, 2021
Pretty sure it is a big, caused by https://github.com/un33k/python-slugify/blob/master/slugify/slugify.py#L179
Looks like there is a test case missing.
adamcunnington-mlg commentedon Nov 2, 2021
@un33k
un33k commentedon Nov 2, 2021
Please note that '-' is a reserved character in slugs. This package allows an atomic replacement of the default separator of '-' with something else towards the end of the process.
A simple preprocess of the text is recommended for special cases.
All PRs are considered provided they remain backward compatible.
adamcunnington-mlg commentedon Nov 2, 2021
Ok, I think this is definitely PR-worthy. I agree that '-' is a reserved character - but this is precisely the reason why you shouldn't remove them. I can pre-process the string; sure; but this seems a bit broken.
Will find time to raise PR but I'm not sure how this can remain backwards compatible as this would be changing (fixing) behaviour where input string contains a - character. Do you imagine this being behind a feature toggle that defaults to current behaviour perhaps?
adamcunnington-mlg commentedon Nov 3, 2021
Also, there's a logical problem with the suggested workaround. Pre-processing the string is highly problematic - what character am I going to replace - with, before I pass it to a call to slugify that is going to replace characters that don't match my regex? I have a very limited set of options and whatever I choose could legitimately appear elsewhere in the string and be erroneously substituted by the post-processing.
The only thing I could do is replace - with some string that i think is going to be reasonably unique. This is brittle and bad. This behaviour should belong to slugify.
un33k commentedon Nov 3, 2021
I think we have examples on how to handle this situation.
python-slugify/test.py
Line 94 in a90d967
un33k commentedon Dec 4, 2021
Closing this now, feel free to reopen if the above example is not addressing your needs and/or you have a non-breaking PR.
ideepu commentedon Dec 14, 2021
I am facing the same issue here. I have a text like this
121232-some text here-some text here againTrying to
slugifythe text with separator' '. Expecting the output121232-some text here-some text here againbut got121232 some text here some text here againIs there any work around for this.
adamcunnington-mlg commentedon Dec 14, 2021
@PradeepTammali workaround is something like this:
un33k commentedon Dec 16, 2021
@PradeepTammali Slugify needs one reserved character, and since the name of the package is
slugifyits job is to convert some random text to adash-delimited clean text for use in URLs. With that said, the delimiter can also be changed to whatever user wants. In short, theaskhere is not doable. I encourage channelling one's energy to raising a meaningful PR instead.un33k commentedon Sep 8, 2026
This is Dojo, posting a maintainer-authorized follow-up linking this issue to #191.
Global dash-to-separator mapping remains unchanged. No new literal-hyphen-preservation API is introduced; modern length budgeting does not resolve that separate request.
The default algorithm remains legacy; improved output rules are opt-in. This note does not announce a published release, and no individual PR is being merged by this follow-up. Thank you for the contribution and discussion.
🚀 Generated with Dojo ⛩️