Neptune to_property_graph errors if the DataFrame is empty

[brianok-aws]

Describe the bug

When writing a dataframe with zero records to Neptune using to_property_graph, an exception is thrown "Error during serialization: Serializer for type com.amazon.neptune.tinkerpop.structure.NeptuneGraph$NeptuneGraphTraversalSource not found"

How to Reproduce

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Create a data frame with zero records and try to write it to Neptune using to_property_graph().

Expected behavior

Nothing will be written but an exception will not be thrown.

Your project

No response

Screenshots

No response

OS

Amazon Linux 2 (via Jupyter Notebook on Sagemaker)

Python version

3.10

AWS SDK for pandas version

3.4.1

Additional context

Related to #2494

[kukushking]

Hi @brianok-aws we can certainly skip the operation and return if there are no rows in the property graph df. Do you foresee any cases where user/client code would like to know they are trying to insert something that does not make sense?

[jaidisido]

I would be in favour of raising an EmptyDataFrame Exception rather than failing silently. Users should realise that their df is empty and they catch the exception on their own if they wish to ignore it

[brianok-aws]

I agree. Any clear exception would be good for this. The customer can always catch and eat it if they have zero-record updates as part of their workflow (or check the count prior to calling). The current exception is essentially the equivalent to NullPointerException in the Gremlin driver. From: jaidisido ***@***.***> Sent: Thursday, November 16, 2023 11:43 AM To: aws/aws-sdk-pandas ***@***.***> Cc: O'Keefe, Brian ***@***.***>; Mention ***@***.***> Subject: Re: [aws/aws-sdk-pandas] Neptune to_property_graph errors if the DataFrame is empty (Issue #2517) I would be in favour of raising an EmptyDataFrame<https://github.com/aws/aws-sdk-pandas/blob/main/awswrangler/exceptions.py#L60> Exception rather than failing silently. Users should realise that their df is empty and they catch the exception on their own if they wish to ignore it — Reply to this email directly, view it on GitHub<#2517 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ARDUYOVDGGDXUKNHE5GK5B3YEY7CPAVCNFSM6AAAAAA7JH4XCWVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTQMJUHAZDKOJRGI>. You are receiving this because you were mentioned.Message ID: ***@***.******@***.***>>

[kukushking]

Fixed in #2526.