Nodes with Controller

class Node:
    def __init__(self, id, alive=True, leader=None, controller=None):
        self.id = id
        self.alive = alive
        self.leader = leader
        self.controller = controller

    def setLeader(self, leader_node):
        self.leader = leader_node

    def getLeader(self):
        return self.leader

    def isAlive(self):
        return self.alive

    def __repr__(self):
        return 'Node instance, id=%s' %self.id


class Controller:
    def __init__(self, nodes=[], name='Controller', leader_node=None):
        self.nodes = nodes
        self.name = name
        self.leader_node = leader_node

    def addNode(self, node):
        if type(node) == Node:
            node.controller = self
            if self.leader_node:
                node.leader = self.leader_node
            self.nodes.append(node)
        else:
            raise TypeError ('setting node muse be a type of Node')

    def getNode(self, node_id):
        return [node for node in self.nodes if node.id == id]

    def setLeader(self):
        arr = []
        arr.append([node.id for node in self.nodes if node.isAlive() == True])
        leader = [node for node in self.nodes if node.id == min(arr[0])]
        self.leader_node = leader[0]
        for node in self.nodes:
            if node.isAlive() == True:
                node.setLeader(self.leader_node)

    def delNode(self, node_id):
        try:
            node_for_del = self.getNode(node_id)
            return 'Node with id=%s was removed' %node_id
        except IndexError:
            return 'Node with id=%s is not avaliable' %node_id
        self.nodes.remove(node_for_del)

    def __repr__(self):
        return '%s' %self.name