python global variable is not saved global

Question

NexusConnectedClients = []

class Thread1(NexusCore.Thread):
    def Run():
        global NexusConnectedClients
        if(IncomingCommand == "ADDCLIENT"):
            NewClientOBJ = [
                LastCID,
                ClientType,
                ClientADDR,
                ClientObject,
                Args[1],
                Args[2],
                '{"events":[]}'
            ]
            NexusConnectedClients.append(NewClientOBJ)
        elif(IncomingCommand == "LISTCLIENTS"):
            SendResponse(NexusConnectedClients)

When i add an client, it is ok. When i read the NexusConnectedClients variable, it is add to the list. But when i run the LISTCLIENTS function, the list is empty. What is wrong?

I Simplified the code a bit. all the variables are set and all other global variables work as they should.

EDIT I found the mistake, nothing wrong with this code but another function deleted the element from the NexusConnectedClients array

Answer 1

You don't need to declare NexusConnectedClients as global since it is visible in the run method. A variable must be declared global when you want to (re)bind a name in the global scope. When a variable is modifiable, and lists are, just modify it.

Instead what you have to do is to regulate the access to the NexusConnectedClients . You are modifying a shared variable inside a thread, maybe more than one. Use a lock. Said that, I think nothing more could be said in a such small snippet.

Answer 2

Solved the problem. Didn't remove an line of code from previous testing. That line resetted the array