Q:

Django: Slug in Vietnamese

A site in Vietnamese, it is virtually no different to English. However, there is a problem that is slug. When I type characters such as "ư", "ơ", "á",... Django is not identified. Solution here is to replace characters that do not sign into. 
Eg: 
ư -> u 
ơ -> o 
á -> a 

One from "những-viên-kẹo" will become "nhung-vien-keo". 
However, I do not know how to do this. Someone help me. Thank you very much!

A:

[edit]
I take it back, django's django.template.defaultfilters.slugify() does what you want, using unicodedata.normalize and .encode('ascii', 'ignore'). Just feeding your string into slugify will work:
from django.template.defaultfilters import slugify
print slugify(u"những-viên-kẹo")

To do this automatically, add this to the .save() method in your models:
from django.template.defaultfilters import slugify
MyModel(models.Model):
    title = models.CharField(max_length=255)
    slug  = models.SlugField(blank=True)

    def save(self, *args, **kwargs):
        if not self.slug:
            self.slug = slugify(self.title)
        super(MyModel, self).save(*args, **kwargs)

The slolution I wrote ealier (below) would still be useful for languages that require additional characters in their translation, eg German's ü->ue, ß->ss etc.
[original post]
Python allows you to use a translation dict to map characters to a replacement string.
A simple version for you case would be:
vietnamese_map = {
    ord(u'ư'): 'u',
    ord(u'ơ'): 'o',
    ord(u'á'): 'a',
    ord(u'n'): 'n',
    ord(u'h'): 'h',
    ord(u'ữ'): 'u',
    ord(u'n'): 'n',
    ord(u'g'): 'g',
    ord(u'v'): 'v',
    ord(u'i'): 'i',
    ord(u'ê'): 'e',
    ord(u'n'): 'n',
    ord(u'k'): 'k',
    ord(u'ẹ'): 'e',
    ord(u'o'): 'o',
}

And then you can call:
print u"những-viên-kẹo".translate(vietnamese_map)

To get:
u"nhung-vien-keo"

For more advanced use (ie a dynamic dict), see eg http://effbot.org/zone/unicode-convert.htm
Note that the above is just to show you what the map needs to look like, it's not a particularly convenient way of entering the data. A more convenient way to do the exact same thing is something like:
_map = u"nn hh ữu nn gg vv ii êe nn kk ẹe oo"
# Take the above string and generate a translation dict
vietnamese_map = dict((ord(m[0]), m[1:]) for m in _map.split())
print u"những-viên-kẹo".translate(vietnamese_map)

