PubNub Python Sample App

This repository contains the files required to run the PubNub Python Quickstart.

PubNub takes care of the infrastructure and APIs needed for the realtime communication layer of your application. Work on your app's logic and let PubNub handle sending and receiving data across the world in less than 100ms.

Get keys

You will need publish and subscribe keys to authenticate your app. Get your keys from the Admin Portal.

Set up the project

If you don't want to copy the code from this document, you can clone the repository and use the files in there.

Create a new folder for your Python scripts.
In that folder, create two files named pub.py and sub.py.
Install the PubNub Python SDK using pip:
```
pip install pubnub
```

Add project files

If you don't want to copy the code from this document, you can clone the repository and use the files in there.

Open the pub.py file and add the following code. Remember to also replace the myPublishKey and mySubscribeKey placeholders with your keys.

from pubnub.callbacks import SubscribeCallback
from pubnub.enums import PNStatusCategory
from pubnub.pnconfiguration import PNConfiguration
from pubnub.pubnub import PubNub

ENTRY = "Earth"
CHANNEL = "the_guide"
the_update = None

# replace the key placeholders with your own PubNub publish and subscribe keys
pnconfig = PNConfiguration()
pnconfig.publish_key = "myPublishKey"
pnconfig.subscribe_key = "mySubscribeKey"
pnconfig.uuid = "serverUUID-PUB"

pubnub = PubNub(pnconfig)

print("*****************************************")
print("* Submit updates to The Guide for Earth *")
print("*     Enter 42 to exit this process     *")
print("*****************************************")

while the_update != "42":
    the_update = input("Enter an update for Earth: ")
    the_message = {"entry": ENTRY, "update": the_update}
    envelope = pubnub.publish().channel(CHANNEL).message(the_message).sync()

    if envelope.status.is_error():
        print("[PUBLISH: fail]")
        print("error: %s" % envelope.status.error)
    else:
        print("[PUBLISH: sent]")
        print("timetoken: %s" % envelope.result.timetoken)

Open the sub.py file and add the following code. Remember to also replace the myPublishKey and mySubscribeKey placeholders with your keys.

import os

from pubnub.callbacks import SubscribeCallback
from pubnub.enums import PNStatusCategory
from pubnub.pnconfiguration import PNConfiguration
from pubnub.pubnub import PubNub

ENTRY = "Earth"
CHANNEL = "the_guide"

# replace the key placeholders with your own PubNub publish and subscribe keys
pnconfig = PNConfiguration()
pnconfig.publish_key = "myPublishKey"
pnconfig.subscribe_key = "mySubscribeKey"
pnconfig.uuid = "serverUUID-SUB"

pubnub = PubNub(pnconfig)

class MySubscribeCallback(SubscribeCallback):
    def message(self, pubnub, event):
        print("[MESSAGE received]")

        if event.message["update"] == "42":
            print("The publisher has ended the session.")
            exit(0)
        else:
            print("{}: {}".format(event.message["entry"], event.message["update"]))

    def presence(self, pubnub, event):
        print("[PRESENCE: {}]".format(event.event))
        print("uuid: {}, channel: {}".format(event.uuid, event.channel))
        print()

    def status(self, pubnub, event):
        if event.category == PNStatusCategory.PNConnectedCategory:
            print("[STATUS: PNConnectedCategory]")
            print("connected to channels: {}".format(event.affected_channels))
            print()

pubnub.add_listener(MySubscribeCallback())
pubnub.subscribe().channels(CHANNEL).with_presence().execute()

print()
print("***************************************************")
print("* Waiting for updates to The Guide about {}... *".format(ENTRY))
print("***************************************************")
print()

Run the app

You first need to start the subcribe process to see the updates you want to publish.

Open the terminal and run the subscribe script by calling python sub.py.

You should see a message that the script is waiting for updates. The subscriber process is implemented to receive updates from the publisher process, so you don't need any further input here.
In a new terminal window, run the publish script by calling python pub.py.

You should see a message that informs you how to exit the process and a prompt that awaits your next update.

When you're finished submitting entries, enter 42 to exit the publisher script. This operation also forces the subscriber script to exit.

Documentation

Support

If you need help or have a general question, contact support@pubnub.com.