removing an instance of an object in python list

Question

I Think this should work but its giving me an error. I have a list that contains objects of class node. I have two different lists

1. open_list

Answer 1

If I read the question right, python's default of comparing the memory locations is the behavior he is looking for, but is not getting. Here's a working example where a custom class is defined Node, it show's that there is no need for the __eq__(self, other).

class Node(object):
    pass

open_node_list = []
node_list = []

for i in range(10):
    a_node = Node()
    open_node_list.append(a_node)
    node_list.append(a_node)

removed = open_node_list.pop()
node_list.remove(removed)

I can't be sure, because you did not show where your open_node_list and node_list were defined, but I suspect that the lists themselves reference the same list object. If that's the case, the popping from open_node_list also pops from node_list, therefore the node will no longer exist when you call remove. Here is example in which node_list and open_node_list are really the same list and so changes to one affect the other:

class Node(object):
  pass

open_node_list = []
node_list = open_node_list # <-- This is a reference, not a copy.

open_node_list.append(Node())
print(node_list)

One way you can copy a list is:

node_list = open_node_list[:]