aiogremlin is a Python 3 driver for the the Tinkerpop 3 Gremlin Server. This module is built on Asyncio and aiohttp aiogremlin is currently in alpha mode, but all major functionality has test coverage.
Since Python 3.4 is not the default version on many systems, it's nice to create a virtualenv that uses Python 3.4 by default. Then use pip to install aiogremlin. Using virtualenvwrapper on Ubuntu 14.04:
$ mkvirtualenv -p /usr/bin/python3.4 aiogremlin
$ pip install aiogremlinFire up the Gremlin Server:
$ ./bin/gremlin-server.shThe GremlinClient communicates asynchronously with the Gremlin Server using websockets. The majority of GremlinClient methods are an asyncio.coroutine, so you will also need to use asyncio:
>>> import asyncio
>>> from aiogremlin import GremlinClientThe Gremlin Server responds with messages in chunks, GremlinClient.submit submits a script to the server, and returns a GremlinResponse object. This object provides the methods: get and the property stream. get collects all of the response messages and returns them as a Python list. stream returns an object of the type GremlinResponseStream that implements a method read. This allows you to read the response without loading all of the messages into memory.
Note that the GremlinClient constructor and the create_client function take keyword only arguments only!
>>> loop = asyncio.get_event_loop()
>>> gc = GremlinClient(url='ws://localhost:8182/', loop=loop) # Default url
# Use get.
>>> @asyncio.coroutine
... def get(gc):
... resp = yield from gc.submit("x + x", bindings={"x": 4})
... result = yield from resp.get()
... return result
>>> result = loop.run_until_complete(get(gc))
>>> result
[Message(status_code=200, data=[8], message={}, metadata='')]
>>> resp = result[0]
>>> resp.status_code
200
>>> resp # Named tuple.
Message(status_code=200, data=[8], message={}, metadata='')
# Use stream.
>>> @asyncio.coroutine
... def stream(gc):
... resp = yield from gc.submit("x + x", bindings={"x": 1})
... while True:
... result = yield from resp.stream.read()
... if result is None:
... break
... print(result)
>>> loop.run_until_complete(stream(gc))
Message(status_code=200, data=[2], message={}, metadata='')
>>> loop.run_until_complete(gc.close()) # Explicitly close client!!!
>>> loop.close()For convenience, aiogremlin also provides a method execute, which is equivalent to calling yield from submit() and then yield from get() in the same coroutine.
>>> loop = asyncio.get_event_loop()
>>> gc = GremlinClient(loop=loop)
>>> execute = gc.execute("x + x", bindings={"x": 4})
>>> result = loop.run_until_complete(execute)
>>> result
[Message(status_code=200, data=[8], message={}, metadata='')]
>>> loop.run_until_complete(gc.close()) # Explicitly close client!!!
>>> loop.close()