spark-instrumented-optimizer/python
zero323 e1b3e9a3d2 [SPARK-29212][ML][PYSPARK] Add common classes without using JVM backend
### What changes were proposed in this pull request?

Implement common base ML classes (`Predictor`, `PredictionModel`, `Classifier`, `ClasssificationModel` `ProbabilisticClassifier`, `ProbabilisticClasssificationModel`, `Regressor`, `RegrssionModel`) for non-Java backends.

Note

- `Predictor` and `JavaClassifier` should be abstract as `_fit` method is not implemented.
- `PredictionModel` should be abstract as `_transform` is not implemented.

### Why are the changes needed?

To provide extensions points for non-JVM algorithms, as well as a public (as opposed to `Java*` variants, which are commonly described in docstrings as private) hierarchy which can be used to distinguish between different classes of predictors.

For longer discussion see [SPARK-29212](https://issues.apache.org/jira/browse/SPARK-29212) and / or https://github.com/apache/spark/pull/25776.

### Does this PR introduce any user-facing change?

It adds new base classes as listed above, but effective interfaces (method resolution order notwithstanding) stay the same.

Additionally "private" `Java*` classes in`ml.regression` and `ml.classification` have been renamed to follow PEP-8 conventions (added leading underscore).

It is for discussion if the same should be done to equivalent classes from `ml.wrapper`.

If we take `JavaClassifier` as an example, type hierarchy will change from

![old pyspark ml classification JavaClassifier](https://user-images.githubusercontent.com/1554276/72657093-5c0b0c80-39a0-11ea-9069-a897d75de483.png)

to

![new pyspark ml classification _JavaClassifier](https://user-images.githubusercontent.com/1554276/72657098-64fbde00-39a0-11ea-8f80-01187a5ea5a6.png)

Similarly the old model

![old pyspark ml classification JavaClassificationModel](https://user-images.githubusercontent.com/1554276/72657103-7513bd80-39a0-11ea-9ffc-59eb6ab61fde.png)

will become

![new pyspark ml classification _JavaClassificationModel](https://user-images.githubusercontent.com/1554276/72657110-80ff7f80-39a0-11ea-9f5c-fe408664e827.png)

### How was this patch tested?

Existing unit tests.

Closes #27245 from zero323/SPARK-29212.

Authored-by: zero323 <mszymkiewicz@gmail.com>
Signed-off-by: zhengruifeng <ruifengz@foxmail.com>
2020-03-04 12:20:02 +08:00
..
docs [SPARK-30880][DOCS] Delete Sphinx Makefile cruft 2020-02-21 14:53:40 +09:00
lib [SPARK-30884][PYSPARK] Upgrade to Py4J 0.10.9 2020-02-20 09:09:30 -08:00
pyspark [SPARK-29212][ML][PYSPARK] Add common classes without using JVM backend 2020-03-04 12:20:02 +08:00
test_coverage [SPARK-7721][PYTHON][TESTS] Adds PySpark coverage generation script 2018-01-22 22:12:50 +09:00
test_support [SPARK-23094][SPARK-23723][SPARK-23724][SQL] Support custom encoding for json files 2018-04-29 11:25:31 +08:00
.coveragerc [SPARK-7721][PYTHON][TESTS] Adds PySpark coverage generation script 2018-01-22 22:12:50 +09:00
.gitignore [SPARK-3946] gitignore in /python includes wrong directory 2014-10-14 14:09:39 -07:00
MANIFEST.in [SPARK-26803][PYTHON] Add sbin subdirectory to pyspark 2019-02-27 08:39:55 -06:00
pylintrc [SPARK-13596][BUILD] Move misc top-level build files into appropriate subdirs 2016-03-07 14:48:02 -08:00
README.md [SPARK-30884][PYSPARK] Upgrade to Py4J 0.10.9 2020-02-20 09:09:30 -08:00
run-tests [SPARK-29672][PYSPARK] update spark testing framework to use python3 2019-11-14 10:18:55 -08:00
run-tests-with-coverage [SPARK-26252][PYTHON] Add support to run specific unittests and/or doctests in python/run-tests script 2018-12-05 15:22:08 +08:00
run-tests.py [SPARK-30480][PYTHON][TESTS] Increases the memory limit being tested in 'WorkerMemoryTest.test_memory_limit' 2020-01-13 18:47:15 +09:00
setup.cfg [SPARK-1267][SPARK-18129] Allow PySpark to be pip installed 2016-11-16 14:22:15 -08:00
setup.py [SPARK-30884][PYSPARK] Upgrade to Py4J 0.10.9 2020-02-20 09:09:30 -08:00

Apache Spark

Spark is a unified analytics engine for large-scale data processing. It provides high-level APIs in Scala, Java, Python, and R, and an optimized engine that supports general computation graphs for data analysis. It also supports a rich set of higher-level tools including Spark SQL for SQL and DataFrames, MLlib for machine learning, GraphX for graph processing, and Structured Streaming for stream processing.

https://spark.apache.org/

Online Documentation

You can find the latest Spark documentation, including a programming guide, on the project web page

Python Packaging

This README file only contains basic information related to pip installed PySpark. This packaging is currently experimental and may change in future versions (although we will do our best to keep compatibility). Using PySpark requires the Spark JARs, and if you are building this from source please see the builder instructions at "Building Spark".

The Python packaging for Spark is not intended to replace all of the other use cases. This Python packaged version of Spark is suitable for interacting with an existing cluster (be it Spark standalone, YARN, or Mesos) - but does not contain the tools required to set up your own standalone Spark cluster. You can download the full version of Spark from the Apache Spark downloads page.

NOTE: If you are using this with a Spark standalone cluster you must ensure that the version (including minor version) matches or you may experience odd errors.

Python Requirements

At its core PySpark depends on Py4J, but some additional sub-packages have their own extra requirements for some features (including numpy, pandas, and pyarrow).