Object in List : how?

[MRAB]

On 23/07/2022 05:28, Khairil Sitanggang wrote:
> Hello Expert:
> 
> I just started using python. Below is a simple code.  I was trying to check
> if, say, NO1 is not in the NODELIST[:].NO
> How can I achieve this purpose?
> 
> Regards,
> -Irfan
> 
> 
> class Node:
>      def __init__(self):
>          self.NO = 0
>          self.A = 20
> 
> NODE = Node()
> NODELIST = []
> 
> NODE.NO = 10
> NODELIST.append(NODE)
> 
> NODE.NO = 20
> NODELIST.append(NODE)
> 
> NODE.NO = 30
> NODELIST.append(NODE)
> 
> 
> NO1 = 20
> if NO1 not in NODELIST[:].NO  ???

No, you can't do it that way. You have to iterate through the list and 
check each member individually:

     if any(NO1 == N.NO for N in NODELIST):

And another thing: you've created only 1 node, and you're changing it 
each time before adding it to the list, so the list ends up with 3 
references to the _same_ object.