'Validate a phone number. Strips parentheses, whitespace and hyphens.'

def clean(self, value):

    super(AUPhoneNumberField, self).clean(value)
    if (value in EMPTY_VALUES):
        return u''
    value = re.sub(u'(\\(|\\)|\\s+|-)', u'', smart_text(value))
    phone_match = PHONE_DIGITS_RE.search(value)
    if phone_match:
        return (u'%s' % phone_match.group(1))
    raise ValidationError(self.error_messages[u'invalid'])
