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https://issues.apache.org/jira/browse/TINKERPOP-2293?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16931191#comment-16931191
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Wolfgang Fahl commented on TINKERPOP-2293:
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Please concentrate on the error message and the point of view of a beginner
that does not want to wade thru oodles of documentation to get the basic
environment working.
First of all [https://pypi.org/project/gremlinpython/
|https://pypi.org/project/gremlinpython/]
shows
{code:java}
>>> g.V().both()[1:3].toList()
[v[2], v[4]]
>>> g.V().both()[1].toList()
[v[2]]
>>> g.V().both().name.toList()
[lop, vadas, josh, marko, marko, josh, peter, ripple, lop, marko, josh,
lop]{code}
as the sample code which is not the complete needed python code. It also does
not explictly mention that you need a server and that this is only a restricted
language variant and not a full implementation.
There is no link to an example or tutorial.
So aftere somebody like me finds out he needs a server he will naturally try it
out. In my case this leads to a non-working server where you get two
error-messages:
Could not initialize gremlin-jython GremlinScriptEngine as init script could
not be evaluated
java.util.concurrent.CompletionException: java.lang.IllegalArgumentException:
gremlin-jython is not an available GremlinScriptEngine
java.util.concurrent.CompletionException: java.lang.IllegalArgumentException:
gremlin-python is not an available GremlinScriptEngine
But there is no hint on how to fix this and what the reason for the problem is.
> Gremlin-Python example not working
> ----------------------------------
>
> Key: TINKERPOP-2293
> URL: https://issues.apache.org/jira/browse/TINKERPOP-2293
> Project: TinkerPop
> Issue Type: Bug
> Components: python
> Affects Versions: 3.3.8
> Reporter: Wolfgang Fahl
> Priority: Major
>
> see
> [https://stackoverflow.com/questions/57936915/how-do-i-get-gremlin-python-with-gremlin-server-3-4-3-to-work]
>
> Steps to reproduce:
> So i wanted to tryout gremlin-python. I found
> [https://pypi.org/project/gremlinpython/] and happily added
>
> {{gremlinpython}}
> to my requirements.txt
>
> {{sudo -H pip install -r requirements.txt}}
> ran successfully- great. Let's find some python code to play with .
> [https://gist.githubusercontent.com/okram/f193d5616563a69ad5714a42c504276f/raw/b8075410e400e18f18360015945f3760d99d044a/gremlin-python-play.py]
> has it.
> Oh - I need a server ...
> Let's download it
> [http://ftp-stud.hs-esslingen.de/pub/Mirrors/ftp.apache.org/dist/tinkerpop/3.4.3/apache-tinkerpop-gremlin-server-3.4.3-bin.zip]
> unzip it and create a starter file for it as outlined in the example above:
>
> {{gspath=$HOME/Downloads/apache-tinkerpop-gremlin-server-3.4.3#$gspath/bin/gremlin-server.sh
> install org.apache.tinkerpop gremlin-python
> 3.4.3$gspath/bin/gremlin-server.sh
> $gspath/conf/gremlin-server-modern-py.yaml}}
> It doesn't work - get a 599 timeout from tornado.
> Look at:
> [Why can't I connect to
> Gremlin-Server?|https://stackoverflow.com/questions/41783800/why-cant-i-connect-to-gremlin-server]
> Try hints e.g. using 0.0.0.0 as host
> Check the startup.
> Oops - there is an error:
> ServerGremlinExecutor - Could not initialize gremlin-python
> GremlinScriptEngine as init script could not be evaluated
> java.util.concurrent.CompletionException: java.lang.IllegalArgumentException:
> gremlin-python is not an available GremlinScriptEngine
> at
> java.util.concurrent.CompletableFuture.reportJoin(CompletableFuture.java:375)
>
> Same for gremlin-jython.
>
> sudo port install jython
>
> does not change the situation.
>
> At least there are some things that would improve the situation:
>
> * add a complete example for python3 including requirements.txt, python code
> install script and description how to configure and start server
> - fix the gremlin-server-modern-py.yaml
> the "-i" optione mentioned in this file does not seem to exist any more.
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