[Tutor] query from sqlalchemy returns AttributeError: 'NoneType' object

[Alan Gauld]

On 02/05/13 23:13, Karthik Sharma wrote:

This doesn't have much to do with learning Python and a lot to do with 
SqlAlchemy so you'd be better off asking on a SqlAlchemy forum I suspect.

However, some basic debugging investigation first may help your cause.
For example...

>      Traceback (most recent call last):
...
>        File "/home/karthik/pox/tutorial.py", line 118, in _handle_PacketIn
>          self.act_like_switch(packet, packet_in)
>        File "/home/karthik/pox/tutorial.py", line 86, in act_like_switch
>          self.send_packet(packet_in.buffer_id,
> packet_in.data,q_res.port_no, packet_in.in_port)
>      AttributeError: 'NoneType' object has no attribute 'port_no'

Have you checked to see what q_res is supposed to be?
And where it comes from? And why it's apparently a NoneType?

Some print statements might be in order?

That will help anyone who can help you to so do.

-- 
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/