def slugify(value, replacement='-'):
   "" Force string convert in unicode ""
    if type(value) is str:
        value = unicode(value, 'UTF-8')

    value = unicodedata.normalize('NFKD', value).encode('ascii', 'ignore').decode('ascii')
    value = re.sub('[^\w\s-]', '', value).strip().lower()
    return mark_safe(re.sub('[-\s]+', replacement, value))