Q80
Single choice
A Spark developer wants to improve the performance of an existing PySpark UDF that runs a hash function that is not available in the standard Spark functions library.
The existing UDF code is:
The developer wants to replace this existing UDF with a Pandas UDF to improve performance.
The developer changes the definition of shake_256_udf to this:
shake_256_udf = sf.pandas_udf(shake_256, StringType())
However, the developer receives the error:
[UNSUPPORTED_SIGNATURE] Unsupported signature: (raw: str) -> str.
What should the signature of the shake_256() function be changed to in order to fix this error?