Today I needed a function to create a slug (an ASCII-only representation of a string). I went Googling a bit, and found an excellend Flask snippet. Problem is, it is designed for Python 2, so I came up with a Python 3 version.
import re
from unicodedata import normalize
_punctuation_re = re.compile(r'[\t !"#$%&\'()*\-/<=>?@\[\\\]^_`{|},.]+')
def slugify(text, delim='-'):
    """
    Generate an ASCII-only slug.
    """
    result = []
    for word in _punctuation_re.split(text.lower()):
        word = normalize('NFKD', word) \
               .encode('ascii', 'ignore') \
               .decode('utf-8')
        if word:
            result.append(word)
    return delim.join(result)
As I don’t really like the transliteration done in the first example (e.g. converting ü to ue), I went with the second example.