Instructions for writing Python user-defined functions (UDFs) for YQL

Using a purely declarative, SQL-like approach to describe task results can sometimes be impractical. You may need to specify which data to JOIN and how to group it declaratively, while handling the data processing logic imperatively. For these use cases, YQL provides a mechanism for writing and calling user-defined functions (UDFs) in Python.
To learn more about UDFs, see Python user-defined functions (UDFs) in YQL.