無法爲這個正確的對象實例分配給ForeignKey的領域

Question

我想保存用戶在我的Django Socket.IO聊天應用程序發送的消息，並有以下型號：

class Conversation(models.Model): 
    """ 
    Conversation with two or more participants. 
    """ 
    name = models.CharField(max_length=20) 
    ... 

class Message(models.Model): 
    """ 
    Single chat message. 
    """ 
    conversation = models.ForeignKey(Conversation,related_name='message_convo') 
    content = models.CharField(max_length=10000) 
    sender = models.ForeignKey(User,related_name='message_sender') 
    sent = models.DateTimeField(auto_now=True) 

我的事件處理程序代碼包括以下情況：

convo = get_object_or_404(Conversation, id=message["room"]) 
... 
m = Message() 
m.conversation = convo, 
m.content = message["message"] 
m.sender = user 
m.save() 

這失敗，完全無意義的信息： ValueError: Cannot assign "(<Conversation: ImmaMode, Century>,)": "Message.conversation" must be a "Conversation" instance.

由於convo由get_object_or_404返回並且是明確 a Conversation實例，有什麼可能導致此？？

Answer 1

m.conversation = convo, 

逗號？