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()) 

当我运行以下命令时：

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

我得到以下错误：

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，您只能远程获得对服务器上图形的引用，而引用可能是TinkerGraph或其他什么。如果要以这种方式加载数据，则必须通过Client实例以脚本形式发出该命令：

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

其中，脚本中的“图形”是服务器上已经存在的Graph实例(可能是空的)。如果您使用的是Gremlin Server，则可以考虑将该加载作为Gremlin Server startup的一部分单独执行，然后使用gremlin-python来查询该数据。这在本例中可能是最好的，因为数据将仅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，它将直接作为gremlin-python的一部分，在这一点上，您将能够直接执行以下操作：

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

在原生python中，它只会工作(同样，Graph实例必须是远程定义的)，尽管文件必须是服务器可读的。

下面是我在Python shell中提交脚本的工作示例，首先使用tornado错误，然后不使用：

$ 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]]