allisonwang-db commented on code in PR #42272: URL: https://github.com/apache/spark/pull/42272#discussion_r1283803283
########## python/docs/source/user_guide/sql/python_udtf.rst: ########## @@ -0,0 +1,140 @@ +.. Licensed to the Apache Software Foundation (ASF) under one + or more contributor license agreements. See the NOTICE file + distributed with this work for additional information + regarding copyright ownership. The ASF licenses this file + to you under the Apache License, Version 2.0 (the + "License"); you may not use this file except in compliance + with the License. You may obtain a copy of the License at + +.. http://www.apache.org/licenses/LICENSE-2.0 + +.. Unless required by applicable law or agreed to in writing, + software distributed under the License is distributed on an + "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + KIND, either express or implied. See the License for the + specific language governing permissions and limitations + under the License. + +=========================================== +Python User-defined Table Functions (UDTFs) +=========================================== + +Spark 3.5 introduces a new type of user-defined fucntion: Python user-defined table functions (UDTFs), +which take zero or more arguments and return a set of rows. + +Implementing a Python UDTF +-------------------------- + +.. currentmodule:: pyspark.sql.functions + +To implement a Python UDTF, you can implement this class: + +.. code-block:: python + + class PythonUDTF: + + def __init__(self) -> None: + """ + Initialize the user-defined table function (UDTF). + + This method is optional to implement and is called once when the UDTF is + instantiated. Use it to perform any initialization required for the UDTF. + """ + ... + + def eval(self, *args: Any) -> Iterator[Any]: + """" + Evaluate the function using the given input arguments. + + This method is required to implement. + + Args: + *args: Arbitrary positional arguments representing the input + to the UDTF. + + Yields: + tuple: A tuple representing a single row in the UDTF result relation. + Yield thisas many times as needed to produce multiple rows. + + Note: + - The result must be a tuple. + - UDTFs do not accept keyword arguments on the calling side. + - Use "yield" to produce one row at a time for the UDTF result relation, + or use "return" to produce multiple rows for the UDTF result relation at once. + + Example: + def eval(self, x: int, y: int): + yield x + y, x - y Review Comment: Sure! I will add a simple one here and a more complex one in the example section below. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org
