Django自定义保存不工作(Django custom save not working)

 所以我有以下型号： 
 
class Info(models.Model):
    user_id = models.BigIntegerField(primary_key=True)
    #...
    def save(self,*args,**kwargs):
        print 1
        is_created = False
        if not self.pk:
            print 2
            is_created = True
        super(Info, self).save(*args, **kwargs)
        print 3
        if is_created:
            print 4
            signals.info_created.send(sender=self.__class__,info=self)
 
 现在我有那些打印语句来跟踪发生了什么。当我运行Info.create(...)或 
 
info = Info(...)
info.save()
 
 我得到以下输出： 
 
1
3
 
 这表明if not self.pk语句被评估为false。 现在我假设这是因为我有一个自定义主键需要在创建该对象时给出。 所以这是我的问题： 我的假设是正确的吗？ 无论是否，我如何才能使这个自定义保存合作？ 

So I have the following model:
 
class Info(models.Model):
    user_id = models.BigIntegerField(primary_key=True)
    #...
    def save(self,*args,**kwargs):
        print 1
        is_created = False
        if not self.pk:
            print 2
            is_created = True
        super(Info, self).save(*args, **kwargs)
        print 3
        if is_created:
            print 4
            signals.info_created.send(sender=self.__class__,info=self)
 
now I have those print statements to keep track of what is going on.when I run either Info.create(...) or
 
info = Info(...)
info.save()
 
I get the following output:
 
1
3
 
which suggests that the if not self.pk statement evaluated to false. Now I assume this is because I have a custom primary key that needs to be given on the creation of that object. So here is my question: is my assumption correct? Regardless if it is or is not, how can I get this custom save to cooperate?

原文：