register (UDTFRegistration)

Registers a Python user-defined table function as a SQL table function.

Syntax

register(name, f)

Parameters

Returns

UserDefinedTableFunction

Notes

Spark uses the return type of the given user-defined table function as the return type of the registered function.

To register a nondeterministic Python table function, first build a nondeterministic user-defined table function and then register it as a SQL function.

Examples

from pyspark.sql.functions import udtf

@udtf(returnType="c1: int, c2: int")
class PlusOne:
    def eval(self, x: int):
        yield x, x + 1

spark.udtf.register(name="plus_one", f=PlusOne)
spark.sql("SELECT * FROM plus_one(1)").collect()
# [Row(c1=1, c2=2)]

# Use it with a lateral join.
spark.sql("SELECT * FROM VALUES (0, 1), (1, 2) t(x, y), LATERAL plus_one(x)").collect()
# [Row(x=0, y=1, c1=0, c2=1), Row(x=1, y=2, c1=1, c2=2)]