

def value_to_string(self, obj):
    data = ''
    if obj:
        qs = getattr(obj, self.name).all()
        data = [instance._get_pk_val() for instance in qs]
    elif (not self.blank):
        choices_list = self.get_choices_default()
        if (len(choices_list) == 1):
            data = [choices_list[0][0]]
    return smart_text(data)

dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.5/django/db/models/fields/related.py ManyToManyField.value_to_string/original