centrifuge-python 0.1

Websocket client for Centrifugo on top of asyncio library

# Centrifuge-python (work in progress)

This is a websocket client for [Centrifugo](https://github.com/centrifugal/centrifugo) server on top of Python asyncio library.

Usage example:

```python
import time
import json
import asyncio
from cent import generate_token
from centrifuge import Client, Credentials


def run(loop):

# Generate credentials.
# In production this must only be done on backend side and you should
# never show secret to client!
user = "3000"
timestamp = str(int(time.time()))
info = json.dumps({"first_name": "Python", "last_name": "Client"})
token = generate_token("secret", user, timestamp, info=info)

address = "ws://localhost:8000/connection/websocket"
credentials = Credentials(user, timestamp, info, token)
client = Client(address, credentials)

yield from client.connect()

@asyncio.coroutine
def message_handler(**kwargs):
print("Message:", kwargs)

@asyncio.coroutine
def join_handler(**kwargs):
print("Join:", kwargs)

@asyncio.coroutine
def leave_handler(**kwargs):
print("Leave:", kwargs)

yield from client.subscribe(
"public:chat",
on_message=message_handler,
on_join=join_handler,
on_leave=leave_handler
)


if __name__ == '__main__':
loop = asyncio.get_event_loop()
asyncio.ensure_future(run(loop))
try:
loop.run_forever()
except KeyboardInterrupt:
print("interrupted")
finally:
loop.close()
```

Or with Python 3.5 async/await syntax:

```python
import time
import json
import asyncio
from centrifuge import Client, Credentials
from cent import generate_token


async def run():

# Generate credentials.
# In production this must only be done on backend side and you should
# never show secret to client!
user = "3000"
timestamp = str(int(time.time()))
info = json.dumps({"first_name": "Python", "last_name": "Client"})
token = generate_token("secret", user, timestamp, info=info)

credentials = Credentials(user, timestamp, info, token)
address = "ws://localhost:8000/connection/websocket"

async def connect_handler(**kwargs):
print("Connected", kwargs)

async def disconnect_handler(**kwargs):
print("Disconnected:", kwargs)

async def connect_error_handler(**kwargs):
print("Error:", kwargs)

client = Client(
address, credentials,
on_connect=connect_handler,
on_disconnect=disconnect_handler,
on_error=connect_error_handler
)

await client.connect()

async def message_handler(**kwargs):
print("Message:", kwargs)

async def join_handler(**kwargs):
print("Join:", kwargs)

async def leave_handler(**kwargs):
print("Leave:", kwargs)

async def error_handler(**kwargs):
print("Sub error:", kwargs)

await client.subscribe(
"public:chat",
on_message=message_handler,
on_join=join_handler,
on_leave=leave_handler,
on_error=error_handler
)


if __name__ == '__main__':
loop = asyncio.get_event_loop()
asyncio.ensure_future(run())
try:
loop.run_forever()
except KeyboardInterrupt:
print("interrupted")
finally:
loop.close()
```

### TODO

* [connection refresh](https://fzambia.gitbooks.io/centrifugal/content/server/connection_check.html) support
* functional tests
* more detailed API description