## What changes were proposed in this pull request?
SPARK-23754 was fixed in #21383 by changing the UDF code to wrap the user function, but this required a hack to save its argspec. This PR reverts this change and fixes the `StopIteration` bug in the worker
## How does this work?
The root of the problem is that when an user-supplied function raises a `StopIteration`, pyspark might stop processing data, if this function is used in a for-loop. The solution is to catch `StopIteration`s exceptions and re-raise them as `RuntimeError`s, so that the execution fails and the error is reported to the user. This is done using the `fail_on_stopiteration` wrapper, in different ways depending on where the function is used:
- In RDDs, the user function is wrapped in the driver, because this function is also called in the driver itself.
- In SQL UDFs, the function is wrapped in the worker, since all processing happens there. Moreover, the worker needs the signature of the user function, which is lost when wrapping it, but passing this signature to the worker requires a not so nice hack.
## How was this patch tested?
Same tests, plus tests for pandas UDFs
Author: edorigatti <emilio.dorigatti@gmail.com>
Closes#21467 from e-dorigatti/fix_udf_hack.
## What changes were proposed in this pull request?
Make sure that `StopIteration`s raised in users' code do not silently interrupt processing by spark, but are raised as exceptions to the users. The users' functions are wrapped in `safe_iter` (in `shuffle.py`), which re-raises `StopIteration`s as `RuntimeError`s
## How was this patch tested?
Unit tests, making sure that the exceptions are indeed raised. I am not sure how to check whether a `Py4JJavaError` contains my exception, so I simply looked for the exception message in the java exception's `toString`. Can you propose a better way?
## License
This is my original work, licensed in the same way as spark
Author: e-dorigatti <emilio.dorigatti@gmail.com>
Author: edorigatti <emilio.dorigatti@gmail.com>
Closes#21383 from e-dorigatti/fix_spark_23754.
## What changes were proposed in this pull request?
More close to Scala API behavior when can't parse input by throwing exception. Add tests.
## How was this patch tested?
Added tests.
Author: Liang-Chi Hsieh <viirya@gmail.com>
Closes#21211 from viirya/SPARK-24131-followup.
## What changes were proposed in this pull request?
We need to determine Spark major and minor versions in PySpark. We can add a `majorMinorVersion` API to PySpark which is similar to the Scala API in `VersionUtils.majorMinorVersion`.
## How was this patch tested?
Added tests.
Author: Liang-Chi Hsieh <viirya@gmail.com>
Closes#21203 from viirya/SPARK-24131.
## What changes were proposed in this pull request?
This cleans up unused imports, mainly from pyspark.sql module. Added a note in function.py that imports `UserDefinedFunction` only to maintain backwards compatibility for using `from pyspark.sql.function import UserDefinedFunction`.
## How was this patch tested?
Existing tests and built docs.
Author: Bryan Cutler <cutlerb@gmail.com>
Closes#20892 from BryanCutler/pyspark-cleanup-imports-SPARK-23700.
The exit() builtin is only for interactive use. applications should use sys.exit().
## What changes were proposed in this pull request?
All usage of the builtin `exit()` function is replaced by `sys.exit()`.
## How was this patch tested?
I ran `python/run-tests`.
Please review http://spark.apache.org/contributing.html before opening a pull request.
Author: Benjamin Peterson <benjamin@python.org>
Closes#20682 from benjaminp/sys-exit.
## What changes were proposed in this pull request?
This PR proposes to support an alternative function from with group aggregate pandas UDF.
The current form:
```
def foo(pdf):
return ...
```
Takes a single arg that is a pandas DataFrame.
With this PR, an alternative form is supported:
```
def foo(key, pdf):
return ...
```
The alternative form takes two argument - a tuple that presents the grouping key, and a pandas DataFrame represents the data.
## How was this patch tested?
GroupbyApplyTests
Author: Li Jin <ice.xelloss@gmail.com>
Closes#20295 from icexelloss/SPARK-23011-groupby-apply-key.
## What changes were proposed in this pull request?
This PR proposes for `pyspark.util._exception_message` to produce the trace from Java side by `Py4JJavaError`.
Currently, in Python 2, it uses `message` attribute which `Py4JJavaError` didn't happen to have:
```python
>>> from pyspark.util import _exception_message
>>> try:
... sc._jvm.java.lang.String(None)
... except Exception as e:
... pass
...
>>> e.message
''
```
Seems we should use `str` instead for now:
aa6c53b590/py4j-python/src/py4j/protocol.py (L412)
but this doesn't address the problem with non-ascii string from Java side -
`https://github.com/bartdag/py4j/issues/306`
So, we could directly call `__str__()`:
```python
>>> e.__str__()
u'An error occurred while calling None.java.lang.String.\n: java.lang.NullPointerException\n\tat java.lang.String.<init>(String.java:588)\n\tat sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)\n\tat sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)\n\tat sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)\n\tat java.lang.reflect.Constructor.newInstance(Constructor.java:422)\n\tat py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:247)\n\tat py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:357)\n\tat py4j.Gateway.invoke(Gateway.java:238)\n\tat py4j.commands.ConstructorCommand.invokeConstructor(ConstructorCommand.java:80)\n\tat py4j.commands.ConstructorCommand.execute(ConstructorCommand.java:69)\n\tat py4j.GatewayConnection.run(GatewayConnection.java:214)\n\tat java.lang.Thread.run(Thread.java:745)\n'
```
which doesn't type coerce unicodes to `str` in Python 2.
This can be actually a problem:
```python
from pyspark.sql.functions import udf
spark.conf.set("spark.sql.execution.arrow.enabled", True)
spark.range(1).select(udf(lambda x: [[]])()).toPandas()
```
**Before**
```
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/.../spark/python/pyspark/sql/dataframe.py", line 2009, in toPandas
raise RuntimeError("%s\n%s" % (_exception_message(e), msg))
RuntimeError:
Note: toPandas attempted Arrow optimization because 'spark.sql.execution.arrow.enabled' is set to true. Please set it to false to disable this.
```
**After**
```
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/.../spark/python/pyspark/sql/dataframe.py", line 2009, in toPandas
raise RuntimeError("%s\n%s" % (_exception_message(e), msg))
RuntimeError: An error occurred while calling o47.collectAsArrowToPython.
: org.apache.spark.SparkException: Job aborted due to stage failure: Task 7 in stage 0.0 failed 1 times, most recent failure: Lost task 7.0 in stage 0.0 (TID 7, localhost, executor driver): org.apache.spark.api.python.PythonException: Traceback (most recent call last):
File "/.../spark/python/pyspark/worker.py", line 245, in main
process()
File "/.../spark/python/pyspark/worker.py", line 240, in process
...
Note: toPandas attempted Arrow optimization because 'spark.sql.execution.arrow.enabled' is set to true. Please set it to false to disable this.
```
## How was this patch tested?
Manually tested and unit tests were added.
Author: hyukjinkwon <gurwls223@gmail.com>
Closes#20680 from HyukjinKwon/SPARK-23517.
## What changes were proposed in this pull request?
Added `util._message_exception` helper to use `str(e)` when `e.message` is unavailable (Python3). Grepped for all occurrences of `.message` in `pyspark/` and these were the only occurrences.
## How was this patch tested?
- Doctests for helper function
## Legal
This is my original work and I license the work to the project under the project’s open source license.
Author: David Gingrich <david@textio.com>
Closes#16845 from dgingrich/topic-spark-19505-py3-exceptions.
