PubNub Python-Twisted SDK 4.8.1
Unsupported SDK
PubNub no longer supports this SDK, but you are welcome to contribute.
Python version support
Python SDK versions 5.0.0 and higher no longer support Python v2.7 and the Twisted framework. If you require support for any of these, use SDK version 4.8.1.
Note that PubNub will stop supporting versions of Python lower than 3.7 at the end of 2021.
Deprecated
NOTICE: Based on current web trends and our own usage data, PubNub's Python Twisted SDK is deprecated as of May 1, 2019. Deprecation means we will no longer be updating the Python Twisted SDK but will continue to support users currently using it. Please feel free to use our other Python SDK offerings as they will continue to be supported and maintained. If you would like to use the Python Twisted SDK specifically, we would love to work with you on keeping this project alive!
Get Code: pip
The simplest way to get started is to install PubNub Python SDK via pip:
pip install 'pubnub>=4.8.1'
Get Code: git
git clone https://github.com/pubnub/python
Get Code: Source
https://github.com/pubnub/python
Hello World
Add PubNub to your project using one of the procedures defined above.
Dependencies
- PyOpenSSL
- Service-Identity
Include the Python SDK in your code
from pubnub.pubnub_twisted import PubNubTwisted
Note
Always set the UUID to uniquely identify the user or device that connects to PubNub. This UUID should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the UUID, you won't be able to connect to PubNub.
from pubnub.enums import PNStatusCategory
from pubnub.pubnub_twisted import PubNubTwisted as PubNub
from pubnub.pnconfiguration import PNConfiguration
from twisted.internet import reactor
from pubnub.callbacks import SubscribeCallback
def main():
pnconf = PNConfiguration()
pnconf.subscribe_key = 'demo'
pnconf.publish_key = 'demo'
pnconf.uuid = "my_custom_uuid"
pubnub = PubNub(pnconf)
def my_publish_callback(result, status):
Copy and paste examples
In addition to the Hello World sample code, we also provide some copy and paste snippets of common API functions:
Init
Instantiate a new Pubnub instance. Only the subscribe_key is mandatory. Also include publish_key if you intend to publish from this instance, and the secret_key if you wish to perform Access Manager administrative operations from this Python-Twisted instance.
Important
For security reasons you should only include the secret-key on a highly secured server. The secret-key is only required for granting rights using our Access Manager.
When you init with secret_key, you get root permissions for the Access Manager. With this feature you don't have to grant access to your servers to access channel data. The servers get all access on all channels.
Note
Always set the UUID to uniquely identify the user or device that connects to PubNub. This UUID should be persisted, and should remain unchanged for the lifetime of the user or the device. If you don't set the UUID, you won't be able to connect to PubNub.
from pubnub.pubnub_twisted import PubNubTwisted
from pubnub.pnconfiguration import PNConfiguration
pnconfig = PNConfiguration()
pnconfig.subscribe_key = "my_subkey"
pnconfig.publish_key = "my_pubkey"
pnconfig.ssl = False
pnconfig.uuid = "my_custom_uuid"
pubnub = PubNubTwisted(pnconfig)
Listeners
Add Listeners
from pubnub.callbacks import SubscribeCallback
class MySubscribeCallback(SubscribeCallback):
def status(self, pubnub, status):
pass
# The status object returned is always related to subscribe but could contain
# information about subscribe, heartbeat, or errors
# use the operationType to switch on different options
if status.operation == PNOperationType.PNSubscribeOperation \
or status.operation == PNOperationType.PNUnsubscribeOperation:
if status.category == PNStatusCategory.PNConnectedCategory:
pass
# This is expected for a subscribe, this means there is no error or issue whatsoever
elif status.category == PNStatusCategory.PNReconnectedCategory:
pass
Remove Listeners
my_listener = MySubscribeCallback()
pubnub.add_listener(my_listener)
# some time later
pubnub.remove_listener(my_listener)
Handling Disconnects
from pubnub.callbacks import SubscribeCallback
from pubnub.enums import PNStatusCategory
class HandleDisconnectsCallback(SubscribeCallback):
def status(self, pubnub, status):
if status.category == PNStatusCategory.PNUnexpectedDisconnectCategory:
# internet got lost, do some magic and call reconnect when ready
pubnub.reconnect()
elif status.category == PNStatusCategory.PNTimeoutCategory:
# do some magic and call reconnect when ready
pubnub.reconnect()
else:
logger.debug(status)
def presence(self, pubnub, presence):
Listener status events
| Category | Description |
|---|---|
PNTimeoutCategory | Failure to establish a connection to PubNub due to a timeout. |
PNBadRequestCategory | The server responded with a bad response error because the request is malformed. |
PNNetworkIssuesCategory | A subscribe event experienced an exception when running. The SDK isn't able to reach PubNub servers. This may be due to many reasons, such as: the machine or device isn't connected to the internet; the internet connection has been lost; your internet service provider is having trouble; or, perhaps the SDK is behind a proxy. |
PNReconnectedCategory | The SDK was able to reconnect to PubNub. |
PNConnectedCategory | SDK subscribed with a new mix of channels. This is fired every time the channel or channel group mix changes. |
PNUnexpectedDisconnectCategory | Previously started subscribe loop did fail and at this moment client disconnected from real-time data channels. |
PNUnknownCategory | Returned when the subscriber gets a non-200 HTTP response code from the server. |
Time
Call time() to verify the client connectivity to the origin:
d = pubnub.time().deferred()
d.addCallback(my_callback)
Subscribe
Subscribe (listen on) a channel:
pubnub.subscribe().channels('my_channel').execute()
Note
The response of the call is handled by adding a Listener. Please see the Listeners section for more details. Listeners should be added before calling the method.
Publish
Publish a message to a channel:
@gen.coroutine
def publish_snippet():
def publish_callback(result, status):
if not status.is_error():
envelope = result
pass # Message successfully published to specified channel.
else:
pass # Handle message publish error. Check 'category' property to find out possible issue
# because of which request did fail.
# Request can be resent using: [status retry];
pubnub.publish().channel('such_channel').message(['hello', 'there']).pn_async(publish_callback)
Here Now
Get occupancy of who's here now on the channel by UUID:
Note
Requires you to enable the Presence add-on for your key. Refer to the How do I enable add-on features for my keys? knowledge base article for details on enabling features.
envelope = yield pubnub.here_now()\
.channels("my_channel", "demo")\
.include_uuids(True)\
.future()
if envelope.status.is_error():
# handle error
return
for channel_data in envelope.result.channels:
print("---")
print("channel: %s" % channel_data.channel_name)
print("occupancy: %s" % channel_data.occupancy)
print("occupants: %s" % channel_data.channel_name)
Presence
Subscribe to real-time Presence events, such as join, leave, and timeout, by UUID. Setting the presence attribute to a callback will subscribe to presents events on my_channel:
Note
Requires you to enable the Presence add-on for your key. Refer to the How do I enable add-on features for my keys? knowledge base article for details on enabling features.
pubnub.subscribe()\
.channels("my_channel")\
.with_presence()\
.execute()
Note
The response of the call is handled by adding a Listener. Please see the Listeners section for more details. Listeners should be added before calling the method.
History
Retrieve published messages from archival storage:
Note
Requires that the Message Persistence add-on is enabled for your key. See how to enable add-on features for your keys.
envelope = yield pubnub.history()\
.channel("history_channel")\
.count(100)\
.future()
Unsubscribe
Stop subscribing (listening) to a channel:
pubnub.unsubscribe().channels("my_channel").execute()
Note
The response of the call is handled by adding a Listener. Please see the Listeners section for more details. Listeners should be added before calling the method.