[C++][Python] Implement to/from substrait for Expression

[asfimport]

DataFusion has the ability to convert between Substrait expressions and it's own internal expressions. (See: https://github.com/datafusion-contrib/datafusion-substrait .) It would be cool if we had a similar conversion for Acero's Expression class.

This might unlock allowing datafusion-python to easily use PyArrow datasets, by using Substrait as intermediate format to pass down filter and projections from Datafusion into the scanner. (See early draft here: datafusion-contrib/datafusion-python#21.)

One problem is that it's unclear what should be the type of the object in Python representing the Substrait expression. IIUC Python doesn't have direct bindings to the Substrait protobuf.

 

Reporter: Will Jones / @wjones127

_{Note: This issue was originally created as ARROW-16844. Please see the migration documentation for further details.}

[asfimport]

Vibhatha Lakmal Abeykoon / @vibhatha:
@wjones127  is there a data-fusion script/example/test which shows the capability?

[asfimport]

Vibhatha Lakmal Abeykoon / @vibhatha:
Just want to see the workflow.

[github-actions]

This issue has been marked as stale because it has had no activity in the past 365 days. Please remove the stale label or comment below, or this issue will be closed in 14 days. If this improvement is still desired but has no current owner, please add the 'Status: needs champion' label.