如何将 tinkergraph 上传到 python/gremlin？

Question

我正在尝试在 python 中使用 gremlin。我导入了以下内容：

from gremlin_python.driver.driver_remote_connection import DriverRemoteConnection
from gremlin_python.structure.graph import Graph
from gremlin_python import statics
from gremlin_python.process.graph_traversal import __
from gremlin_python.process.strategies import *
from gremlin_python.process.traversal import *
import asyncio
statics.load_statics(globals()) 

当我运行这个时：

graph = TinkerGraph.open() 
graph.io(graphml()).readGraph('air-routes.graphml') 

我收到以下错误：

NameError: name 'TinkerGraph' is not defined

我该如何解决这个问题？

Answer 1

Python 中没有 TinkerGraph。在 gremlin-python 中，您只能在服务器上远程获得对图形的引用，这可能是 TinkerGraph 或其他东西。如果您想以这种方式加载数据，则必须通过 Client 实例将该命令作为脚本发出：

client = Client('ws://localhost:45940/gremlin', 'g')
client.submit("graph.io(graphml()).readGraph('air-routes.graphml');[]").all().result()

该脚本中的“graph”是服务器上已存在的Graph 实例（并且可能为空）。如果您使用 Gremlin Server，您可能会考虑将加载作为Gremlin Server startup 的一部分单独加载，然后仅使用 gremlin-python 来查询该数据。在这个例子中这可能是最好的，因为数据只会在服务器启动时出现。

请注意，在 3.4.0 中，我们引入了 io() 步骤，它将直接成为 gremlin-python 的一部分，此时您将能够直接执行：

g.io('air-routes.xml').read()

在本机 python 中，它可以正常工作（同样，Graph 实例必须远程定义）尽管文件​​必须可由服务器读取。

这是我在 Python shell 中提交脚本的工作示例，首先出现龙卷风错误，然后没有：

$ env/bin/python
Python 3.4.3 (default, Nov 28 2017, 16:41:13) 
[GCC 4.8.4] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from gremlin_python.driver.client import Client
>>> client = Client('ws://localhost:8182/gremlin', 'g')
>>> client.submit("g.V()").all().result()
Traceback (most recent call last):
  File "/home/smallette/git/apache/incubator-tinkerpop/gremlin-python/target/python3/gremlin_python/driver/client.py", line 51, in __init__
    from gremlin_python.driver.tornado.transport import (
  File "/home/smallette/git/apache/incubator-tinkerpop/gremlin-python/target/python3/gremlin_python/driver/tornado/transport.py", line 19, in <module>
    from tornado import ioloop, websocket
ImportError: No module named 'tornado'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/smallette/git/apache/incubator-tinkerpop/gremlin-python/target/python3/gremlin_python/driver/driver_remote_connection.py", line 45, in __init__
    password=password)
  File "/home/smallette/git/apache/incubator-tinkerpop/gremlin-python/target/python3/gremlin_python/driver/client.py", line 54, in __init__
    raise Exception("Please install Tornado or pass"
Exception: Please install Tornado or passcustom transport factory
>>> exit
Use exit() or Ctrl-D (i.e. EOF) to exit
>>> exit()
$ env/bin/pip install tornado
Collecting tornado
Collecting backports-abc>=0.4 (from tornado)
  Using cached https://files.pythonhosted.org/packages/7d/56/6f3ac1b816d0cd8994e83d0c4e55bc64567532f7dc543378bd87f81cebc7/backports_abc-0.5-py2.py3-none-any.whl
Installing collected packages: backports-abc, tornado
Successfully installed backports-abc-0.5 tornado-5.1.1
smallette@ubuntu:~/git/apache/incubator-tinkerpop/gremlin-python/target/python3$ env/bin/python
Python 3.4.3 (default, Nov 28 2017, 16:41:13) 
[GCC 4.8.4] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from gremlin_python import statics
>>> client = Client('ws://localhost:8182/gremlin', 'g')
>>> client.submit("g.V()").all().result()
[v[0]]