How to determine the variable size of subscription

[JHQRAIN]

I want use a value val ,I want determine the variable size of subscription# '' print("Python: New data change event", node, val)''

import sys sys.path.insert(0, "..") import logging

from opcua import Client

class SubHandler(object):

"""
Client to subscription. It will receive events from server
"""

def datachange_notification(self, node, val, data):
    print("Python: New data change event", node, val)

def event_notification(self, event):
    print("Python: New event", event)

if name == "main":

from IPython import embed

logging.basicConfig(level=logging.WARN)
client = Client("opc.tcp://192.168.56.100:49320/OPCUA/SimulationServer/")
#client = Client("opc.tcp://192.168.56.100:4840/OPCUA/SimulationServer/")
#client = Client("opc.tcp://olivier:olivierpass@localhost:53530/OPCUA/SimulationServer/")
try:
    client.connect()
    root = client.get_root_node()
    print("Root is", root)
    print("childs of root are: ", root.get_children())
    print("name of root is", root.get_browse_name())
    objects = client.get_objects_node()
    print("childs og objects are: ", objects.get_children())

    tag1 = client.get_node("ns=2;s=Channel1.Device1.Tag1")
    print("tag1 is: {0} with value {1} ".format(tag1, tag1.get_value()))
    tag2 = client.get_node("ns=2;s=Channel1.Device1.Tag2")
    print("tag2 is: {0} with value {1} ".format(tag2, tag2.get_value()))

    handler = SubHandler()
    sub = client.create_subscription(500, handler)
    handle1 = sub.subscribe_data_change(tag1)
    handle2 = sub.subscribe_data_change(tag2)

    from IPython import embed
    embed()

    sub.unsubscribe(handle1)
    sub.unsubscribe(handle2)
    sub.delete()
finally:
    client.disconnect()

[zerox1212]

I have no idea what you are asking for and your code isn't formatted at all.

[JHQRAIN]

Thank you for answering my question！Well, I mean：“how to print(v) in the main function ”: from opcua import Client

class SubHandler(object): def datachange_notification(self, node, val, data): global v v = val

print("Python: New data change event", node, v)

    return v

client = Client("opc.tcp://127.0.0.1:49320") client.connect() tag2 = client.get_node("ns=2;s=test.test.VW100") handler = SubHandler() sub = client.create_subscription(200, handler) handle1 = sub.subscribe_data_change(tag2) print(v)