pyspark.sql.UDTFRegistration.register#

UDTFRegistration.register(name, f)[source]#

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

New in version 3.5.0.

Parameters
namestr

The name of the user-defined table function in SQL statements.

ffunction or pyspark.sql.functions.udtf()

The user-defined table function.

Returns
function

The registered user-defined table function.

Notes

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

To register a nondeterministic Python table function, users need to 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 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)]