Identify, incorporate a slugify routine into utils

[stucka]

I don't know what's necessary as far as licensing goes. Django's has worked for me in the past, but then that part of it goes under a different license.

[zstumgoren]

Let's just add our own simple slugify function in a utils.py. That way we can avoid the heavy dependency on Django and sidestep licensing issues (we typically use Apache 2.0)

[newsroomdev]

@stucka was there a particular aspect or feature of Django slugify which we could incorporate ourselves quickly? Here's slugify's source code (it's rather short). We might be able to lightly refactor it and add it as utils/slugify.py without importing Django. (I'd recommend an inline comment acknowledging, thanking, and linking to the source code.)

def slugify(value, allow_unicode=False):
    """
    Convert to ASCII if 'allow_unicode' is False. Convert spaces or repeated
    dashes to single dashes. Remove characters that aren't alphanumerics,
    underscores, or hyphens. Convert to lowercase. Also strip leading and
    trailing whitespace, dashes, and underscores.
    """
    value = str(value)
    if allow_unicode:
        value = unicodedata.normalize("NFKC", value)
    else:
        value = (
            unicodedata.normalize("NFKD", value)
            .encode("ascii", "ignore")
            .decode("ascii")
        )
    value = re.sub(r"[^\w\s-]", "", value.lower())
    return re.sub(r"[-\s]+", "-", value).strip("-_")

[stucka]

I have no deep knowledge here -- just thinking we need a slugify routine, and it should be standardized. It can be an external dependency as far as I'm concerned, like python-slugify, but I don't know what effect if any that has on licensing.

I also see a very simple answer here:
https://stackoverflow.com/a/8366771