USE THIS https://github.com/stephenlb/pubnub-python-docker - THE CODE BELOW IS FINE< BUT IF YOU WANT DOCKERFILE, USE REPO

pubnub-python-publish.py

import pubnub#pubnub==4.0.2
import time
from pubnub.pnconfiguration import PNConfiguration
from pubnub.pubnub import PubNub

pnconf = PNConfiguration()
pnconf.subscribe_key = "demo"
pnconf.publish_key = "demo"
pubnub = PubNub(pnconf)

def show(msg, stat):
    if msg and stat: print( msg.timetoken, stat.status_code )
    else           : print( "Error", stat and stat.status_code )

while True:
    pubnub.publish().channel("change_log").message("hello").async(show)
    time.sleep(2)

pubnub-python-subscribe.py

import pubnub

from pubnub.pnconfiguration import PNConfiguration
from pubnub.pubnub          import PubNub, SubscribeListener

class DatabaseSync(SubscribeListener):
    def message( self, pubnub, data ):
        print( "Saving to Database: ", data.message )

pnconfig               = PNConfiguration()
pnconfig.subscribe_key = 'demo'
pnconfig.publish_key   = 'demo'
pubnub                 = PubNub(pnconfig)

pubnub.add_listener(DatabaseSync())
pubnub.subscribe().channels("change_log").execute()

USE THIS https://github.com/stephenlb/pubnub-python-docker