Script client.py sends xy data over a datagram socket to the server.py which displays them on matplotlib. Run the server in one console and then the client on another. You should see an interactive display of xy data as they arrive. Using Python 3.

client.py

import time
import socket
import math
import json

addr = ("127.0.0.1", 12000)

clientSocket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
clientSocket.settimeout(1)

for x in range(1000):
    point = dict(x=float(x), y=math.sin(x/10))
    message = json.dumps(point)
    b = bytearray()
    b.extend(map(ord, message))
    clientSocket.sendto(b, addr)
    print('sent ', message)
    time.sleep(0.2)

server.py

import numpy as np
import matplotlib.pyplot as plt
import time
import socket
import json

serverSocket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
serverSocket.bind(('', 12000))

plt.ion()

while True:
    message, address = serverSocket.recvfrom(1024)
    point = json.loads(message)  # expects json in the format {"x": 123.23, "y": 321.2}
    print('recv:', point)
    plt.plot(point['x'], point['y'], 'ob')
    plt.pause(0.001)

while True:
    plt.pause(0.05)