dtenedor commented on code in PR #42272: URL: https://github.com/apache/spark/pull/42272#discussion_r1282415737
########## 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. Review Comment: Can we also describe the mapping between provided scalar argument(s) and the attributes of any provided relation argument with the ordering of these `*args` here? For example, we could mention that each provided scalar argument with index i in 0...N gets assigned to `*args` index i here, with the exception of at most one input relation argument at provided index j, and its attributes are injected one-by-one into the `*args` starting at index j? -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
