Thank you. I did it as you said. Yes, I forgot to create a new object Node() for each of the 3 instances.
The reason I wanted to do as I asked was that I expected Python provides that convenient feature (since it is a high level language). I use Matlab a lot and it is so rich of features that allow us to process object array in many different ways. Anyway, as I said, I just started playing with Python, and I like it so much. Thanks to Visual Studio Code making coding very enjoyable. Get Outlook for iOS<https://aka.ms/o0ukef> ________________________________ From: Python-list <python-list-bounces+ksit70=gmail....@python.org> on behalf of MRAB <pyt...@mrabarnett.plus.com> Sent: Saturday, July 23, 2022 4:57:34 PM To: python-list@python.org <python-list@python.org> Subject: Re: Object in List : how? 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. -- https://mail.python.org/mailman/listinfo/python-list -- https://mail.python.org/mailman/listinfo/python-list
