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LabVIEW cluster and python node


I have a question!
I'm trying to send cluster data from LabVIEW to python through python node, but so far I have no clue how LabVIEW send cluster data to python (I mean in what format or form), have tried many python parsing options but still getting an error (end of topic), any ideas of how to parse cluster LabVIEW data in python!?

simple LabVIEW vi and python script would be really appreciated!

LabVIEW: (Hex 0x687) There was an error in executing the specified function. Python returned the following error: <class 'TypeError'> bad argument type for built-in operation

Message 1 of 10

LabVIEW clusters can be sent to Python... but it looks like we forgot to include a shipping example for that. We will fix that mistake in the next version. In the meantime, here's the script to catch a cluster:

def SumClusterIntegers(cluster):
    "cluster[0] -> Integer, cluster[1] -> String, cluster[2] -> Integer"
    return cluster[0] + cluster[2]

And here's the VI:



Attached are the script and the VI. I hope that helps.

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Message 2 of 10

There is one shipping example that uses clusters, but it doesn't explicitly call out that it does. It is here:


We still should add an explicitly tagged example for this common operation.

Message 3 of 10

it's really helpful thanks a lot!
but not quite what I meant, I want is the return value to be a cluster!

like in the picture I uploaded in cluster x2 (numeric3 would be 10 and string would be abc)

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Message 4 of 10

Screen Shot 2018-10-04 at 18.40.37.png

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Message 5 of 10

Hey ramymagdy,


Were you ever able to get this to work?  I am also working have a cluster output from the Python node, but running into the same error (1671) you show here.  I have a work around of calling separate functions for each, but this isn't as efficient as I'd like.  




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Message 6 of 10

Hi RG,

Sometimes it happens still, but occurrence dropped dramatically, check if you have same bits versions of both labview and python for example 32-bit or 64-bit


also check if you have same datatypes passed in and out the python script and that labview datatypes matches them. Try your way around the node itself that’s the most important link between labview and python, and check other posts they can be really helpful to figure it out. Good luck

Message 7 of 10

Thanks ramy!  I had a few things mixed up, but with your guidance, I had it working in just a few minutes this morning.



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Message 8 of 10

That’s great, happy to help 🙂

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Message 9 of 10

When i connect LabVIEW cluster to input of python node, json.loads is getting list instead of dictionary. Although, i see this help and able to read input like mentioned cluster0,cluster1.... 

But, I saw in website that there will be array/list ,  cluster/dictionary, array/tuple combination. If i have cluster input, dictionary items must be there but i am receiving list.

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Message 10 of 10