Django的pre_save時不保存更改

Question

我需要保存模型之前修改某些值：

@receiver(pre_save) 
def model_pre_save(sender, instance, *args, **kwargs): 
    print instance.path # prints "old_path" 
    instance.path = some_path() 
    print instance.path # prints "new_path" 

但保存instance.path後，仍然等於"old_path"。

Answer 1

pre_save例如更改沒有穿過，你應該使用update_fields按照文檔

pre_save