listener.py

#!/usr/bin/env python3
#
# This is a NetworkTables client (eg, the DriverStation/coprocessor side).
# You need to tell it the IP address of the NetworkTables server (the
# robot or simulator).
#
# This shows how to use a listener to listen for changes in NetworkTables
# values. This will print out any changes detected on the SmartDashboard
# table.
#

import sys
import time
from networktables import NetworkTable

# To see messages from networktables, you must setup logging
import logging
logging.basicConfig(level=logging.DEBUG)

if len(sys.argv) != 2:
    print("Error: specify an IP to connect to!")
    exit(0)

ip = sys.argv[1]

NetworkTable.setIPAddress(ip)
NetworkTable.setClientMode()
NetworkTable.initialize()

def valueChanged(table, key, value, isNew):
    print("valueChanged: key: '%s'; value: %s; isNew: %s" % (key, value, isNew))
        
sd = NetworkTable.getTable("SmartDashboard")
sd.addTableListener(valueChanged)

while True:
    time.sleep(1)