A. Python UDFs can contain both new code and calls to existing packages

B. For each row passed to a UDF, the UDF returns either a scalar (i.e. single) value or, if defined as a table function, a set of rows.

C. A UDF also gives you a way to encapsulate functionality so that you can call it repeatedly from multiple places in code

D. A scalar function (UDF) returns a tabular value for each input row