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99 commits

Author SHA1 Message Date
Shantanu 77f2ca6cce [MINOR][PYTHON] Fix spacing in error message
### What changes were proposed in this pull request?
Fixes spacing in an error message

### Why are the changes needed?
Makes error messages easier to read

### Does this PR introduce _any_ user-facing change?
Yes, it changes the error message

### How was this patch tested?
This patch doesn't affect any logic, so existing tests should cover it

Closes #29264 from hauntsaninja/patch-1.

Authored-by: Shantanu <12621235+hauntsaninja@users.noreply.github.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
2020-07-28 11:22:18 +09:00
HyukjinKwon 4ad9bfd53b [SPARK-32138] Drop Python 2.7, 3.4 and 3.5
### What changes were proposed in this pull request?

This PR aims to drop Python 2.7, 3.4 and 3.5.

Roughly speaking, it removes all the widely known Python 2 compatibility workarounds such as `sys.version` comparison, `__future__`. Also, it removes the Python 2 dedicated codes such as `ArrayConstructor` in Spark.

### Why are the changes needed?

 1. Unsupport EOL Python versions
 2. Reduce maintenance overhead and remove a bit of legacy codes and hacks for Python 2.
 3. PyPy2 has a critical bug that causes a flaky test, SPARK-28358 given my testing and investigation.
 4. Users can use Python type hints with Pandas UDFs without thinking about Python version
 5. Users can leverage one latest cloudpickle, https://github.com/apache/spark/pull/28950. With Python 3.8+ it can also leverage C pickle.

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

Yes, users cannot use Python 2.7, 3.4 and 3.5 in the upcoming Spark version.

### How was this patch tested?

Manually tested and also tested in Jenkins.

Closes #28957 from HyukjinKwon/SPARK-32138.

Authored-by: HyukjinKwon <gurwls223@apache.org>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
2020-07-14 11:22:44 +09:00
HyukjinKwon 6fb22aa42d
[SPARK-31748][PYTHON] Document resource module in PySpark doc and rename/move classes
### What changes were proposed in this pull request?

This PR is kind of a followup for SPARK-29641 and SPARK-28234. This PR proposes:

1.. Document the new `pyspark.resource` module introduced at 95aec091e4, in PySpark API docs.

2.. Move classes into fewer and simpler modules

Before:

```
pyspark
├── resource
│   ├── executorrequests.py
│   │   ├── class ExecutorResourceRequest
│   │   └── class ExecutorResourceRequests
│   ├── taskrequests.py
│   │   ├── class TaskResourceRequest
│   │   └── class TaskResourceRequests
│   ├── resourceprofilebuilder.py
│   │   └── class ResourceProfileBuilder
│   ├── resourceprofile.py
│   │   └── class ResourceProfile
└── resourceinformation
    └── class ResourceInformation
```

After:

```
pyspark
└── resource
    ├── requests.py
    │   ├── class ExecutorResourceRequest
    │   ├── class ExecutorResourceRequests
    │   ├── class TaskResourceRequest
    │   └── class TaskResourceRequests
    ├── profile.py
    │   ├── class ResourceProfileBuilder
    │   └── class ResourceProfile
    └── information.py
        └── class ResourceInformation
```

3.. Minor docstring fix e.g.:

```diff
-     param name the name of the resource
-     param addresses an array of strings describing the addresses of the resource
+     :param name: the name of the resource
+     :param addresses: an array of strings describing the addresses of the resource
+
+     .. versionadded:: 3.0.0
```

### Why are the changes needed?

To document APIs, and move Python modules to fewer and simpler modules.

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

No, the changes are in unreleased branches.

### How was this patch tested?

Manually tested via:

```bash
cd python
./run-tests --python-executables=python3 --modules=pyspark-core
./run-tests --python-executables=python3 --modules=pyspark-resource
```

Closes #28569 from HyukjinKwon/SPARK-28234-SPARK-29641-followup.

Authored-by: HyukjinKwon <gurwls223@apache.org>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
2020-05-19 17:09:37 -07:00
Thomas Graves 95aec091e4 [SPARK-29641][PYTHON][CORE] Stage Level Sched: Add python api's and tests
### What changes were proposed in this pull request?

As part of the Stage level scheduling features, add the Python api's to set resource profiles.
This also adds the functionality to properly apply the pyspark memory configuration when specified in the ResourceProfile. The pyspark memory configuration is being passed in the task local properties. This was an easy way to get it to the PythonRunner that needs it. I modeled this off how the barrier task scheduling is passing the addresses. As part of this I added in the JavaRDD api's because those are needed by python.

### Why are the changes needed?

python api for this feature

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

Yes adds the java and python apis for user to specify a ResourceProfile to use stage level scheduling.

### How was this patch tested?

unit tests and manually tested on yarn. Tests also run to verify it errors properly on standalone and local mode where its not yet supported.

Closes #28085 from tgravescs/SPARK-29641-pr-base.

Lead-authored-by: Thomas Graves <tgraves@nvidia.com>
Co-authored-by: Thomas Graves <tgraves@apache.org>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
2020-04-23 10:20:39 +09:00
HyukjinKwon c279e6b091 [SPARK-30722][DOCS][FOLLOW-UP] Explicitly mention the same entire input/output length restriction of Series Iterator UDF
### What changes were proposed in this pull request?

This PR explicitly mention that the requirement of Iterator of Series to Iterator of Series and Iterator of Multiple Series to Iterator of Series (previously Scalar Iterator pandas UDF).

The actual limitation of this UDF is the same length of the _entire input and output_, instead of each series's length. Namely you can do something as below:

```python
from typing import Iterator, Tuple
import pandas as pd
from pyspark.sql.functions import pandas_udf

pandas_udf("long")
def func(
        iterator: Iterator[pd.Series]) -> Iterator[pd.Series]:
    return iter([pd.concat(iterator)])

spark.range(100).select(func("id")).show()
```

This characteristic allows you to prefetch the data from the iterator to speed up, compared to the regular Scalar to Scalar (previously Scalar pandas UDF).

### Why are the changes needed?

To document the correct restriction and characteristics of a feature.

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

Yes in the documentation but only in unreleased branches.

### How was this patch tested?

Github Actions should test the documentation build

Closes #28160 from HyukjinKwon/SPARK-30722-followup.

Authored-by: HyukjinKwon <gurwls223@apache.org>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
2020-04-09 16:46:27 +09:00
HyukjinKwon 4fafdcd63b [SPARK-26412][PYTHON][FOLLOW-UP] Improve error messages in Scala iterator pandas UDF
### What changes were proposed in this pull request?

This PR proposes to improve the error message from Scalar iterator pandas UDF.

### Why are the changes needed?

To show the correct error messages.

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

Yes, but only in unreleased branches.

```python
import pandas as pd
from pyspark.sql.functions import pandas_udf, PandasUDFType

pandas_udf('long', PandasUDFType.SCALAR_ITER)
def pandas_plus_one(iterator):
      for _ in iterator:
            yield pd.Series(1)

spark.range(10).repartition(1).select(pandas_plus_one("id")).show()
```
```python
import pandas as pd
from pyspark.sql.functions import pandas_udf, PandasUDFType

pandas_udf('long', PandasUDFType.SCALAR_ITER)
def pandas_plus_one(iterator):
      for _ in iterator:
            yield pd.Series(list(range(20)))

spark.range(10).repartition(1).select(pandas_plus_one("id")).show()
```

**Before:**

```
RuntimeError: The number of output rows of pandas iterator UDF should
be the same with input rows. The input rows number is 10 but the output
rows number is 1.
```
```
AssertionError: Pandas MAP_ITER UDF outputted more rows than input rows.
```

**After:**

```
RuntimeError: The length of output in Scalar iterator pandas UDF should be
the same with the input's; however, the length of output was 1 and the length
of input was 10.
```
```
AssertionError: Pandas SCALAR_ITER UDF outputted more rows than input rows.
```

### How was this patch tested?

Unittests were fixed accordingly.

Closes #28135 from HyukjinKwon/SPARK-26412-followup.

Authored-by: HyukjinKwon <gurwls223@apache.org>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
2020-04-09 13:14:41 +09:00
yi.wu 68d7edf949 [SPARK-30812][SQL][CORE] Revise boolean config name to comply with new config naming policy
### What changes were proposed in this pull request?

Revise below config names to comply with [new config naming policy](http://apache-spark-developers-list.1001551.n3.nabble.com/DISCUSS-naming-policy-of-Spark-configs-td28875.html):

SQL:
* spark.sql.execution.subquery.reuse.enabled / [SPARK-27083](https://issues.apache.org/jira/browse/SPARK-27083)
* spark.sql.legacy.allowNegativeScaleOfDecimal.enabled / [SPARK-30252](https://issues.apache.org/jira/browse/SPARK-30252)
* spark.sql.adaptive.optimizeSkewedJoin.enabled / [SPARK-29544](https://issues.apache.org/jira/browse/SPARK-29544)
* spark.sql.legacy.property.nonReserved / [SPARK-30183](https://issues.apache.org/jira/browse/SPARK-30183)
* spark.sql.streaming.forceDeleteTempCheckpointLocation.enabled / [SPARK-26389](https://issues.apache.org/jira/browse/SPARK-26389)
* spark.sql.analyzer.failAmbiguousSelfJoin.enabled / [SPARK-28344](https://issues.apache.org/jira/browse/SPARK-28344)
* spark.sql.adaptive.shuffle.reducePostShufflePartitions.enabled / [SPARK-30074](https://issues.apache.org/jira/browse/SPARK-30074)
* spark.sql.execution.pandas.arrowSafeTypeConversion / [SPARK-25811](https://issues.apache.org/jira/browse/SPARK-25811)
* spark.sql.legacy.looseUpcast / [SPARK-24586](https://issues.apache.org/jira/browse/SPARK-24586)
* spark.sql.legacy.arrayExistsFollowsThreeValuedLogic / [SPARK-28052](https://issues.apache.org/jira/browse/SPARK-28052)
* spark.sql.sources.ignoreDataLocality.enabled / [SPARK-29189](https://issues.apache.org/jira/browse/SPARK-29189)
* spark.sql.adaptive.shuffle.fetchShuffleBlocksInBatch.enabled / [SPARK-9853](https://issues.apache.org/jira/browse/SPARK-9853)

CORE:
* spark.eventLog.erasureCoding.enabled / [SPARK-25855](https://issues.apache.org/jira/browse/SPARK-25855)
* spark.shuffle.readHostLocalDisk.enabled / [SPARK-30235](https://issues.apache.org/jira/browse/SPARK-30235)
* spark.scheduler.listenerbus.logSlowEvent.enabled / [SPARK-29001](https://issues.apache.org/jira/browse/SPARK-29001)
* spark.resources.coordinate.enable / [SPARK-27371](https://issues.apache.org/jira/browse/SPARK-27371)
* spark.eventLog.logStageExecutorMetrics.enabled / [SPARK-23429](https://issues.apache.org/jira/browse/SPARK-23429)

### Why are the changes needed?

To comply with the config naming policy.

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

No. Configurations listed above are all newly added in Spark 3.0.

### How was this patch tested?

Pass Jenkins.

Closes #27563 from Ngone51/revise_boolean_conf_name.

Authored-by: yi.wu <yi.wu@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
2020-02-18 20:39:50 +08:00
HyukjinKwon ee8d661058 [SPARK-30434][PYTHON][SQL] Move pandas related functionalities into 'pandas' sub-package
### What changes were proposed in this pull request?

This PR proposes to move pandas related functionalities into pandas package. Namely:

```bash
pyspark/sql/pandas
├── __init__.py
├── conversion.py  # Conversion between pandas <> PySpark DataFrames
├── functions.py   # pandas_udf
├── group_ops.py   # Grouped UDF / Cogrouped UDF + groupby.apply, groupby.cogroup.apply
├── map_ops.py     # Map Iter UDF + mapInPandas
├── serializers.py # pandas <> PyArrow serializers
├── types.py       # Type utils between pandas <> PyArrow
└── utils.py       # Version requirement checks
```

In order to separately locate `groupby.apply`, `groupby.cogroup.apply`, `mapInPandas`, `toPandas`, and `createDataFrame(pdf)` under `pandas` sub-package, I had to use a mix-in approach which Scala side uses often by `trait`, and also pandas itself uses this approach (see `IndexOpsMixin` as an example) to group related functionalities. Currently, you can think it's like Scala's self typed trait. See the structure below:

```python
class PandasMapOpsMixin(object):
    def mapInPandas(self, ...):
        ...
        return ...

    # other Pandas <> PySpark APIs
```

```python
class DataFrame(PandasMapOpsMixin):

    # other DataFrame APIs equivalent to Scala side.

```

Yes, This is a big PR but they are mostly just moving around except one case `createDataFrame` which I had to split the methods.

### Why are the changes needed?

There are pandas functionalities here and there and I myself gets lost where it was. Also, when you have to make a change commonly for all of pandas related features, it's almost impossible now.

Also, after this change, `DataFrame` and `SparkSession` become more consistent with Scala side since pandas is specific to Python, and this change separates pandas-specific APIs away from `DataFrame` or `SparkSession`.

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

No.

### How was this patch tested?

Existing tests should cover. Also, I manually built the PySpark API documentation and checked.

Closes #27109 from HyukjinKwon/pandas-refactoring.

Authored-by: HyukjinKwon <gurwls223@apache.org>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
2020-01-09 10:22:50 +09:00
Bago Amirbekian 8152a87235 [SPARK-28978][ ] Support > 256 args to python udf
### What changes were proposed in this pull request?

On the worker we express lambda functions as strings and then eval them to create a "mapper" function. This make the code hard to read & limits the # of arguments a udf can support to 256 for python <= 3.6.

This PR rewrites the mapper functions as nested functions instead of "lambda strings" and allows passing in more than 255 args.

### Why are the changes needed?
The jira ticket associated with this issue describes how MLflow uses udfs to consume columns as features. This pattern isn't unique and a limit of 255 features is quite low.

### Does this PR introduce any user-facing change?
Users can now pass more than 255 cols to a udf function.

### How was this patch tested?
Added a unit test for passing in > 255 args to udf.

Closes #26442 from MrBago/replace-lambdas-on-worker.

Authored-by: Bago Amirbekian <bago@databricks.com>
Signed-off-by: Xiangrui Meng <meng@databricks.com>
2019-11-08 19:19:14 -08:00
Xianyang Liu 1e599e5005 [SPARK-29582][PYSPARK] Support TaskContext.get() in a barrier task from Python side
### What changes were proposed in this pull request?

Add support of `TaskContext.get()` in a barrier task from Python side, this makes it easier to migrate legacy user code to barrier execution mode.

### Why are the changes needed?

In Spark Core, there is a `TaskContext` object which is a singleton. We set a task context instance which can be TaskContext or BarrierTaskContext before the task function startup, and unset it to none after the function end. So we can both get TaskContext and BarrierTaskContext with the object. However we can only get the BarrierTaskContext with `BarrierTaskContext`, we will get `None` if we get it by `TaskContext.get` in a barrier stage.

This is useful when people switch from normal code to barrier code, and only need a little update.

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

Yes.
Previously:
```python
def func(iterator):
    task_context = TaskContext.get() . # this could be None.
    barrier_task_context = BarrierTaskContext.get() # get the BarrierTaskContext instance
    ...

rdd.barrier().mapPartitions(func)
```

Proposed:
```python
def func(iterator):
    task_context = TaskContext.get() . # this could also get the BarrierTaskContext instance which is same as barrier_task_context
    barrier_task_context = BarrierTaskContext.get() # get the BarrierTaskContext instance
    ...

rdd.barrier().mapPartitions(func)
```

### How was this patch tested?

New UT tests.

Closes #26239 from ConeyLiu/barrier_task_context.

Authored-by: Xianyang Liu <xianyang.liu@intel.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
2019-10-31 13:10:44 +09:00
Xianjin YE 8c8016a152 [SPARK-21045][PYTHON] Allow non-ascii string as an exception message from python execution in Python 2
### What changes were proposed in this pull request?

This PR allows non-ascii string as an exception message in Python 2 by explicitly en/decoding in case of `str` in Python 2.

### Why are the changes needed?

Previously PySpark will hang when the `UnicodeDecodeError` occurs and the real exception cannot be passed to the JVM side.

See the reproducer as below:

```python
def f():
    raise Exception("中")
spark = SparkSession.builder.master('local').getOrCreate()
spark.sparkContext.parallelize([1]).map(lambda x: f()).count()
```

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

User may not observe hanging for the similar cases.

### How was this patch tested?

Added a new test and manually checking.

This pr is based on #18324, credits should also go to dataknocker.
To make lint-python happy for python3, it also includes a followup fix for #25814

Closes #25847 from advancedxy/python_exception_19926_and_21045.

Authored-by: Xianjin YE <advancedxy@gmail.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
2019-09-21 08:09:19 +09:00
Chris Martin 05988b256e [SPARK-27463][PYTHON] Support Dataframe Cogroup via Pandas UDFs
### What changes were proposed in this pull request?

Adds a new cogroup Pandas UDF.  This allows two grouped dataframes to be cogrouped together and apply a (pandas.DataFrame, pandas.DataFrame) -> pandas.DataFrame UDF to each cogroup.

**Example usage**

```
from pyspark.sql.functions import pandas_udf, PandasUDFType
df1 = spark.createDataFrame(
   [(20000101, 1, 1.0), (20000101, 2, 2.0), (20000102, 1, 3.0), (20000102, 2, 4.0)],
   ("time", "id", "v1"))

df2 = spark.createDataFrame(
   [(20000101, 1, "x"), (20000101, 2, "y")],
    ("time", "id", "v2"))

pandas_udf("time int, id int, v1 double, v2 string", PandasUDFType.COGROUPED_MAP)
   def asof_join(l, r):
      return pd.merge_asof(l, r, on="time", by="id")

df1.groupby("id").cogroup(df2.groupby("id")).apply(asof_join).show()

```

        +--------+---+---+---+
        |    time| id| v1| v2|
        +--------+---+---+---+
        |20000101|  1|1.0|  x|
        |20000102|  1|3.0|  x|
        |20000101|  2|2.0|  y|
        |20000102|  2|4.0|  y|
        +--------+---+---+---+

### How was this patch tested?

Added unit test test_pandas_udf_cogrouped_map

Closes #24981 from d80tb7/SPARK-27463-poc-arrow-stream.

Authored-by: Chris Martin <chris@cmartinit.co.uk>
Signed-off-by: Bryan Cutler <cutlerb@gmail.com>
2019-09-17 17:13:50 -07:00
Thomas Graves f84cca2d84 [SPARK-28234][CORE][PYTHON] Add python and JavaSparkContext support to get resources
## What changes were proposed in this pull request?

Add python api support and JavaSparkContext support for resources().  I needed the JavaSparkContext support for it to properly translate into python with the py4j stuff.

## How was this patch tested?

Unit tests added and manually tested in local cluster mode and on yarn.

Closes #25087 from tgravescs/SPARK-28234-python.

Authored-by: Thomas Graves <tgraves@nvidia.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
2019-07-11 09:32:58 +09:00
HyukjinKwon 5c55812400 [SPARK-28198][PYTHON][FOLLOW-UP] Rename mapPartitionsInPandas to mapInPandas with a separate evaluation type
## What changes were proposed in this pull request?

This PR proposes to rename `mapPartitionsInPandas` to `mapInPandas` with a separate evaluation type .

Had an offline discussion with rxin, mengxr and cloud-fan

The reason is basically:

1. `SCALAR_ITER` doesn't make sense with `mapPartitionsInPandas`.
2. It cannot share the same Pandas UDF, for instance, at `select` and `mapPartitionsInPandas` unlike `GROUPED_AGG` because iterator's return type is different.
3. `mapPartitionsInPandas` -> `mapInPandas` - see https://github.com/apache/spark/pull/25044#issuecomment-508298552 and https://github.com/apache/spark/pull/25044#issuecomment-508299764

Renaming `SCALAR_ITER` as `MAP_ITER` is abandoned due to 2. reason.

For `XXX_ITER`, it might have to have a different interface in the future if we happen to add other versions of them. But this is an orthogonal topic with `mapPartitionsInPandas`.

## How was this patch tested?

Existing tests should cover.

Closes #25044 from HyukjinKwon/SPARK-28198.

Authored-by: HyukjinKwon <gurwls223@apache.org>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
2019-07-05 09:22:41 +09:00
HyukjinKwon 02f4763286 [SPARK-28198][PYTHON] Add mapPartitionsInPandas to allow an iterator of DataFrames
## What changes were proposed in this pull request?

This PR proposes to add `mapPartitionsInPandas` API to DataFrame by using existing `SCALAR_ITER` as below:

1. Filtering via setting the column

```python
from pyspark.sql.functions import pandas_udf, PandasUDFType

df = spark.createDataFrame([(1, 21), (2, 30)], ("id", "age"))

pandas_udf(df.schema, PandasUDFType.SCALAR_ITER)
def filter_func(iterator):
    for pdf in iterator:
        yield pdf[pdf.id == 1]

df.mapPartitionsInPandas(filter_func).show()
```

```
+---+---+
| id|age|
+---+---+
|  1| 21|
+---+---+
```

2. `DataFrame.loc`

```python
from pyspark.sql.functions import pandas_udf, PandasUDFType
import pandas as pd

df = spark.createDataFrame([['aa'], ['bb'], ['cc'], ['aa'], ['aa'], ['aa']], ["value"])

pandas_udf(df.schema, PandasUDFType.SCALAR_ITER)
def filter_func(iterator):
    for pdf in iterator:
        yield pdf.loc[pdf.value.str.contains('^a'), :]

df.mapPartitionsInPandas(filter_func).show()
```

```
+-----+
|value|
+-----+
|   aa|
|   aa|
|   aa|
|   aa|
+-----+
```

3. `pandas.melt`

```python
from pyspark.sql.functions import pandas_udf, PandasUDFType
import pandas as pd

df = spark.createDataFrame(
    pd.DataFrame({'A': {0: 'a', 1: 'b', 2: 'c'},
                  'B': {0: 1, 1: 3, 2: 5},
                  'C': {0: 2, 1: 4, 2: 6}}))

pandas_udf("A string, variable string, value long", PandasUDFType.SCALAR_ITER)
def filter_func(iterator):
    for pdf in iterator:
        import pandas as pd
        yield pd.melt(pdf, id_vars=['A'], value_vars=['B', 'C'])

df.mapPartitionsInPandas(filter_func).show()
```

```
+---+--------+-----+
|  A|variable|value|
+---+--------+-----+
|  a|       B|    1|
|  a|       C|    2|
|  b|       B|    3|
|  b|       C|    4|
|  c|       B|    5|
|  c|       C|    6|
+---+--------+-----+
```

The current limitation of `SCALAR_ITER` is that it doesn't allow different length of result, which is pretty critical in practice - for instance, we cannot simply filter by using Pandas APIs but we merely just map N to N. This PR allows map N to M like flatMap.

This API mimics the way of `mapPartitions` but keeps API shape of `SCALAR_ITER` by allowing different results.

### How does this PR implement?

This PR adds mimics both `dapply` with Arrow optimization and Grouped Map Pandas UDF. At Python execution side, it reuses existing `SCALAR_ITER` code path.

Therefore, externally, we don't introduce any new type of Pandas UDF but internally we use another evaluation type code `205` (`SQL_MAP_PANDAS_ITER_UDF`).

This approach is similar with Pandas' Windows function implementation with Grouped Aggregation Pandas UDF functions - internally we have `203` (`SQL_WINDOW_AGG_PANDAS_UDF`) but externally we just share the same `GROUPED_AGG`.

## How was this patch tested?

Manually tested and unittests were added.

Closes #24997 from HyukjinKwon/scalar-udf-iter.

Authored-by: HyukjinKwon <gurwls223@apache.org>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
2019-07-02 10:54:16 +09:00
WeichenXu 31e7c37354 [SPARK-28185][PYTHON][SQL] Closes the generator when Python UDFs stop early
## What changes were proposed in this pull request?

 Closes the generator when Python UDFs stop early.

### Manually verification on pandas iterator UDF and mapPartitions

```python
from pyspark.sql import SparkSession
from pyspark.sql.functions import pandas_udf, PandasUDFType
from pyspark.sql.functions import col, udf
from pyspark.taskcontext import TaskContext
import time
import os

spark.conf.set('spark.sql.execution.arrow.maxRecordsPerBatch', '1')
spark.conf.set('spark.sql.pandas.udf.buffer.size', '4')

pandas_udf("int", PandasUDFType.SCALAR_ITER)
def fi1(it):
    try:
        for batch in it:
            yield batch + 100
            time.sleep(1.0)
    except BaseException as be:
        print("Debug: exception raised: " + str(type(be)))
        raise be
    finally:
        open("/tmp/000001.tmp", "a").close()

df1 = spark.range(10).select(col('id').alias('a')).repartition(1)

# will see log Debug: exception raised: <class 'GeneratorExit'>
# and file "/tmp/000001.tmp" generated.
df1.select(col('a'), fi1('a')).limit(2).collect()

def mapper(it):
    try:
        for batch in it:
                yield batch
    except BaseException as be:
        print("Debug: exception raised: " + str(type(be)))
        raise be
    finally:
        open("/tmp/000002.tmp", "a").close()

df2 = spark.range(10000000).repartition(1)

# will see log Debug: exception raised: <class 'GeneratorExit'>
# and file "/tmp/000002.tmp" generated.
df2.rdd.mapPartitions(mapper).take(2)

```

## How was this patch tested?

Unit test added.

Please review https://spark.apache.org/contributing.html before opening a pull request.

Closes #24986 from WeichenXu123/pandas_iter_udf_limit.

Authored-by: WeichenXu <weichen.xu@databricks.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
2019-06-28 17:10:25 +09:00
WeichenXu 6d441dcdc6 [SPARK-26412][PYSPARK][SQL] Allow Pandas UDF to take an iterator of pd.Series or an iterator of tuple of pd.Series
## What changes were proposed in this pull request?

Allow Pandas UDF to take an iterator of pd.Series or an iterator of tuple of pd.Series.
Note the UDF input args will be always one iterator:
* if the udf take only column as input, the iterator's element will be pd.Series (corresponding to the column values batch)
* if the udf take multiple columns as inputs, the iterator's element will be a tuple composed of multiple `pd.Series`s, each one corresponding to the multiple columns as inputs (keep the same order). For example:
```
pandas_udf("int", PandasUDFType.SCALAR_ITER)
def the_udf(iterator):
    for col1_batch, col2_batch in iterator:
        yield col1_batch + col2_batch

df.select(the_udf("col1", "col2"))
```
The udf above will add col1 and col2.

I haven't add unit tests, but manually tests show it works fine. So it is ready for first pass review.
We can test several typical cases:

```
from pyspark.sql import SparkSession
from pyspark.sql.functions import pandas_udf, PandasUDFType
from pyspark.sql.functions import udf
from pyspark.taskcontext import TaskContext

df = spark.createDataFrame([(1, 20), (3, 40)], ["a", "b"])

pandas_udf("int", PandasUDFType.SCALAR_ITER)
def fi1(it):
    pid = TaskContext.get().partitionId()
    print("DBG: fi1: do init stuff, partitionId=" + str(pid))
    for batch in it:
        yield batch + 100
    print("DBG: fi1: do close stuff, partitionId=" + str(pid))

pandas_udf("int", PandasUDFType.SCALAR_ITER)
def fi2(it):
    pid = TaskContext.get().partitionId()
    print("DBG: fi2: do init stuff, partitionId=" + str(pid))
    for batch in it:
        yield batch + 10000
    print("DBG: fi2: do close stuff, partitionId=" + str(pid))

pandas_udf("int", PandasUDFType.SCALAR_ITER)
def fi3(it):
    pid = TaskContext.get().partitionId()
    print("DBG: fi3: do init stuff, partitionId=" + str(pid))
    for x, y in it:
        yield x + y * 10 + 100000
    print("DBG: fi3: do close stuff, partitionId=" + str(pid))

pandas_udf("int", PandasUDFType.SCALAR)
def fp1(x):
    return x + 1000

udf("int")
def fu1(x):
    return x + 10

# test select "pandas iter udf/pandas udf/sql udf" expressions at the same time.
# Note this case the `fi1("a"), fi2("b"), fi3("a", "b")` will generate only one plan,
# and `fu1("a")`, `fp1("a")` will generate another two separate plans.
df.select(fi1("a"), fi2("b"), fi3("a", "b"), fu1("a"), fp1("a")).show()

# test chain two pandas iter udf together
# Note this case `fi2(fi1("a"))` will generate only one plan
# Also note the init stuff/close stuff call order will be like:
# (debug output following)
#     DBG: fi2: do init stuff, partitionId=0
#     DBG: fi1: do init stuff, partitionId=0
#     DBG: fi1: do close stuff, partitionId=0
#     DBG: fi2: do close stuff, partitionId=0
df.select(fi2(fi1("a"))).show()

# test more complex chain
# Note this case `fi1("a"), fi2("a")` will generate one plan,
# and `fi3(fi1_output, fi2_output)` will generate another plan
df.select(fi3(fi1("a"), fi2("a"))).show()
```

## How was this patch tested?

To be added.

Please review http://spark.apache.org/contributing.html before opening a pull request.

Closes #24643 from WeichenXu123/pandas_udf_iter.

Lead-authored-by: WeichenXu <weichen.xu@databricks.com>
Co-authored-by: Xiangrui Meng <meng@databricks.com>
Signed-off-by: Xiangrui Meng <meng@databricks.com>
2019-06-15 08:29:20 -07:00
Takuya UESHIN 594be7a911 [SPARK-27240][PYTHON] Use pandas DataFrame for struct type argument in Scalar Pandas UDF.
## What changes were proposed in this pull request?

Now that we support returning pandas DataFrame for struct type in Scalar Pandas UDF.

If we chain another Pandas UDF after the Scalar Pandas UDF returning pandas DataFrame, the argument of the chained UDF will be pandas DataFrame, but currently we don't support pandas DataFrame as an argument of Scalar Pandas UDF. That means there is an inconsistency between the chained UDF and the single UDF.

We should support taking pandas DataFrame for struct type argument in Scalar Pandas UDF to be consistent.
Currently pyarrow >=0.11 is supported.

## How was this patch tested?

Modified and added some tests.

Closes #24177 from ueshin/issues/SPARK-27240/structtype_argument.

Authored-by: Takuya UESHIN <ueshin@databricks.com>
Signed-off-by: Bryan Cutler <cutlerb@gmail.com>
2019-03-25 11:26:09 -07:00
Bryan Cutler be08b415da [SPARK-27163][PYTHON] Cleanup and consolidate Pandas UDF functionality
## What changes were proposed in this pull request?

This change is a cleanup and consolidation of 3 areas related to Pandas UDFs:

1) `ArrowStreamPandasSerializer` now inherits from `ArrowStreamSerializer` and uses the base class `dump_stream`, `load_stream` to create Arrow reader/writer and send Arrow record batches.  `ArrowStreamPandasSerializer` makes the conversions to/from Pandas and converts to Arrow record batch iterators. This change removed duplicated creation of Arrow readers/writers.

2) `createDataFrame` with Arrow now uses `ArrowStreamPandasSerializer` instead of doing its own conversions from Pandas to Arrow and sending record batches through `ArrowStreamSerializer`.

3) Grouped Map UDFs now reuse existing logic in `ArrowStreamPandasSerializer` to send Pandas DataFrame results as a `StructType` instead of separating each column from the DataFrame. This makes the code a little more consistent with the Python worker, but does require that the returned StructType column is flattened out in `FlatMapGroupsInPandasExec` in Scala.

## How was this patch tested?

Existing tests and ran tests with pyarrow 0.12.0

Closes #24095 from BryanCutler/arrow-refactor-cleanup-UDFs.

Authored-by: Bryan Cutler <cutlerb@gmail.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
2019-03-21 17:44:51 +09:00
TigerYang414 60a899b8c3 [SPARK-27041][PYSPARK] Use imap() for python 2.x to resolve oom issue
## What changes were proposed in this pull request?

With large partition, pyspark may exceeds executor memory limit and trigger out of memory for python 2.7.
This is because map() is used. Unlike in python3.x, python 2.7 map() will generate a list and need to read all data into memory.

The proposed fix will use imap in python 2.7 and it has been verified.

## How was this patch tested?
Manual test.
(Please explain how this patch was tested. E.g. unit tests, integration tests, manual tests)
(If this patch involves UI changes, please attach a screenshot; otherwise, remove this)

Please review http://spark.apache.org/contributing.html before opening a pull request.

Closes #23954 from TigerYang414/patch-1.

Lead-authored-by: TigerYang414 <39265202+TigerYang414@users.noreply.github.com>
Co-authored-by: Hyukjin Kwon <gurwls223@apache.org>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
2019-03-12 10:23:26 -05:00
Bryan Cutler ddc2052ebd [SPARK-23836][PYTHON] Add support for StructType return in Scalar Pandas UDF
## What changes were proposed in this pull request?

This change adds support for returning StructType from a scalar Pandas UDF, where the return value of the function is a pandas.DataFrame. Nested structs are not supported and an error will be raised, child types can be any other type currently supported.

## How was this patch tested?

Added additional unit tests to `test_pandas_udf_scalar`

Closes #23900 from BryanCutler/pyspark-support-scalar_udf-StructType-SPARK-23836.

Authored-by: Bryan Cutler <cutlerb@gmail.com>
Signed-off-by: Bryan Cutler <cutlerb@gmail.com>
2019-03-07 08:52:24 -08:00
Liang-Chi Hsieh f92d276653 [SPARK-25811][PYSPARK] Raise a proper error when unsafe cast is detected by PyArrow
## What changes were proposed in this pull request?

Since 0.11.0, PyArrow supports to raise an error for unsafe cast ([PR](https://github.com/apache/arrow/pull/2504)). We should use it to raise a proper error for pandas udf users when such cast is detected.

Added a SQL config `spark.sql.execution.pandas.arrowSafeTypeConversion` to disable Arrow safe type check.

## How was this patch tested?

Added test and manually test.

Closes #22807 from viirya/SPARK-25811.

Authored-by: Liang-Chi Hsieh <viirya@gmail.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
2019-01-22 14:54:41 +08:00
Sean Owen c2d0d700b5 [SPARK-26640][CORE][ML][SQL][STREAMING][PYSPARK] Code cleanup from lgtm.com analysis
## What changes were proposed in this pull request?

Misc code cleanup from lgtm.com analysis. See comments below for details.

## How was this patch tested?

Existing tests.

Closes #23571 from srowen/SPARK-26640.

Lead-authored-by: Sean Owen <sean.owen@databricks.com>
Co-authored-by: Hyukjin Kwon <gurwls223@apache.org>
Co-authored-by: Sean Owen <srowen@gmail.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
2019-01-17 19:40:39 -06:00
Li Jin 86100df54b [SPARK-24561][SQL][PYTHON] User-defined window aggregation functions with Pandas UDF (bounded window)
## What changes were proposed in this pull request?

This PR implements a new feature - window aggregation Pandas UDF for bounded window.

#### Doc:
https://docs.google.com/document/d/14EjeY5z4-NC27-SmIP9CsMPCANeTcvxN44a7SIJtZPc/edit#heading=h.c87w44wcj3wj

#### Example:
```
from pyspark.sql.functions import pandas_udf, PandasUDFType
from pyspark.sql.window import Window

df = spark.range(0, 10, 2).toDF('v')
w1 = Window.partitionBy().orderBy('v').rangeBetween(-2, 4)
w2 = Window.partitionBy().orderBy('v').rowsBetween(-2, 2)

pandas_udf('double', PandasUDFType.GROUPED_AGG)
def avg(v):
    return v.mean()

df.withColumn('v_mean', avg(df['v']).over(w1)).show()
# +---+------+
# |  v|v_mean|
# +---+------+
# |  0|   1.0|
# |  2|   2.0|
# |  4|   4.0|
# |  6|   6.0|
# |  8|   7.0|
# +---+------+

df.withColumn('v_mean', avg(df['v']).over(w2)).show()
# +---+------+
# |  v|v_mean|
# +---+------+
# |  0|   2.0|
# |  2|   3.0|
# |  4|   4.0|
# |  6|   5.0|
# |  8|   6.0|
# +---+------+

```

#### High level changes:

This PR modifies the existing WindowInPandasExec physical node to deal with unbounded (growing, shrinking and sliding) windows.

* `WindowInPandasExec` now share the same base class as `WindowExec` and share utility functions. See `WindowExecBase`
* `WindowFunctionFrame` now has two new functions `currentLowerBound` and `currentUpperBound` - to return the lower and upper window bound for the current output row. It is also modified to allow `AggregateProcessor` == null. Null aggregator processor is used for `WindowInPandasExec` where we don't have an aggregator and only uses lower and upper bound functions from `WindowFunctionFrame`
* The biggest change is in `WindowInPandasExec`, where it is modified to take `currentLowerBound` and `currentUpperBound` and write those values together with the input data to the python process for rolling window aggregation. See `WindowInPandasExec` for more details.

#### Discussion
In benchmarking, I found numpy variant of the rolling window UDF is much faster than the pandas version:

Spark SQL window function: 20s
Pandas variant: ~80s
Numpy variant: 10s
Numpy variant with numba: 4s

Allowing numpy variant of the vectorized UDFs is something I want to discuss because of the performance improvement, but doesn't have to be in this PR.

## How was this patch tested?

New tests

Closes #22305 from icexelloss/SPARK-24561-bounded-window-udf.

Authored-by: Li Jin <ice.xelloss@gmail.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
2018-12-18 09:15:21 +08:00
hyukjinkwon 9cda9a892d [SPARK-26080][PYTHON] Skips Python resource limit on Windows in Python worker
## What changes were proposed in this pull request?

`resource` package is a Unix specific package. See https://docs.python.org/2/library/resource.html and https://docs.python.org/3/library/resource.html.

Note that we document Windows support:

> Spark runs on both Windows and UNIX-like systems (e.g. Linux, Mac OS).

This should be backported into branch-2.4 to restore Windows support in Spark 2.4.1.

## How was this patch tested?

Manually mocking the changed logics.

Closes #23055 from HyukjinKwon/SPARK-26080.

Lead-authored-by: hyukjinkwon <gurwls223@apache.org>
Co-authored-by: Hyukjin Kwon <gurwls223@apache.org>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
2018-12-02 17:41:08 +08:00
gatorsmile 8c2edf46d0 [SPARK-24324][PYTHON][FOLLOW-UP] Rename the Conf to spark.sql.legacy.execution.pandas.groupedMap.assignColumnsByName
## What changes were proposed in this pull request?

Add the legacy prefix for spark.sql.execution.pandas.groupedMap.assignColumnsByPosition and rename it to spark.sql.legacy.execution.pandas.groupedMap.assignColumnsByName

## How was this patch tested?
The existing tests.

Closes #22540 from gatorsmile/renameAssignColumnsByPosition.

Lead-authored-by: gatorsmile <gatorsmile@gmail.com>
Co-authored-by: Hyukjin Kwon <gurwls223@gmail.com>
Signed-off-by: hyukjinkwon <gurwls223@apache.org>
2018-09-26 09:32:51 +08:00
Imran Rashid 58419b9267 [PYSPARK] Updates to pyspark broadcast 2018-09-17 14:06:09 -05:00
Imran Rashid 38391c9aa8 [SPARK-25253][PYSPARK] Refactor local connection & auth code
This eliminates some duplication in the code to connect to a server on localhost to talk directly to the jvm.  Also it gives consistent ipv6 and error handling.  Two other incidental changes, that shouldn't matter:
1) python barrier tasks perform authentication immediately (rather than waiting for the BARRIER_FUNCTION indicator)
2) for `rdd._load_from_socket`, the timeout is only increased after authentication.

Closes #22247 from squito/py_connection_refactor.

Authored-by: Imran Rashid <irashid@cloudera.com>
Signed-off-by: hyukjinkwon <gurwls223@apache.org>
2018-08-29 09:47:38 +08:00
Ryan Blue 7ad18ee9f2 [SPARK-25004][CORE] Add spark.executor.pyspark.memory limit.
## What changes were proposed in this pull request?

This adds `spark.executor.pyspark.memory` to configure Python's address space limit, [`resource.RLIMIT_AS`](https://docs.python.org/3/library/resource.html#resource.RLIMIT_AS). Limiting Python's address space allows Python to participate in memory management. In practice, we see fewer cases of Python taking too much memory because it doesn't know to run garbage collection. This results in YARN killing fewer containers. This also improves error messages so users know that Python is consuming too much memory:

```
  File "build/bdist.linux-x86_64/egg/package/library.py", line 265, in fe_engineer
    fe_eval_rec.update(f(src_rec_prep, mat_rec_prep))
  File "build/bdist.linux-x86_64/egg/package/library.py", line 163, in fe_comp
    comparisons = EvaluationUtils.leven_list_compare(src_rec_prep.get(item, []), mat_rec_prep.get(item, []))
  File "build/bdist.linux-x86_64/egg/package/evaluationutils.py", line 25, in leven_list_compare
    permutations = sorted(permutations, reverse=True)
  MemoryError
```

The new pyspark memory setting is used to increase requested YARN container memory, instead of sharing overhead memory between python and off-heap JVM activity.

## How was this patch tested?

Tested memory limits in our YARN cluster and verified that MemoryError is thrown.

Author: Ryan Blue <blue@apache.org>

Closes #21977 from rdblue/SPARK-25004-add-python-memory-limit.
2018-08-28 12:31:33 -07:00
Xingbo Jiang ad45299d04 [SPARK-25095][PYSPARK] Python support for BarrierTaskContext
## What changes were proposed in this pull request?

Add method `barrier()` and `getTaskInfos()` in python TaskContext, these two methods are only allowed for barrier tasks.

## How was this patch tested?

Add new tests in `tests.py`

Closes #22085 from jiangxb1987/python.barrier.

Authored-by: Xingbo Jiang <xingbo.jiang@databricks.com>
Signed-off-by: Xiangrui Meng <meng@databricks.com>
2018-08-21 15:54:30 -07:00
Bryan Cutler a5849ad9a3 [SPARK-24324][PYTHON] Pandas Grouped Map UDF should assign result columns by name
## What changes were proposed in this pull request?

Currently, a `pandas_udf` of type `PandasUDFType.GROUPED_MAP` will assign the resulting columns based on index of the return pandas.DataFrame.  If a new DataFrame is returned and constructed using a dict, then the order of the columns could be arbitrary and be different than the defined schema for the UDF.  If the schema types still match, then no error will be raised and the user will see column names and column data mixed up.

This change will first try to assign columns using the return type field names.  If a KeyError occurs, then the column index is checked if it is string based. If so, then the error is raised as it is most likely a naming mistake, else it will fallback to assign columns by position and raise a TypeError if the field types do not match.

## How was this patch tested?

Added a test that returns a new DataFrame with column order different than the schema.

Author: Bryan Cutler <cutlerb@gmail.com>

Closes #21427 from BryanCutler/arrow-grouped-map-mixesup-cols-SPARK-24324.
2018-06-24 09:28:46 +08:00
Li Jin 9786ce66c5 [SPARK-22239][SQL][PYTHON] Enable grouped aggregate pandas UDFs as window functions with unbounded window frames
## What changes were proposed in this pull request?
This PR enables using a grouped aggregate pandas UDFs as window functions. The semantics is the same as using SQL aggregation function as window functions.

```
       >>> from pyspark.sql.functions import pandas_udf, PandasUDFType
       >>> from pyspark.sql import Window
       >>> df = spark.createDataFrame(
       ...     [(1, 1.0), (1, 2.0), (2, 3.0), (2, 5.0), (2, 10.0)],
       ...     ("id", "v"))
       >>> pandas_udf("double", PandasUDFType.GROUPED_AGG)
       ... def mean_udf(v):
       ...     return v.mean()
       >>> w = Window.partitionBy('id')
       >>> df.withColumn('mean_v', mean_udf(df['v']).over(w)).show()
       +---+----+------+
       | id|   v|mean_v|
       +---+----+------+
       |  1| 1.0|   1.5|
       |  1| 2.0|   1.5|
       |  2| 3.0|   6.0|
       |  2| 5.0|   6.0|
       |  2|10.0|   6.0|
       +---+----+------+
```

The scope of this PR is somewhat limited in terms of:
(1) Only supports unbounded window, which acts essentially as group by.
(2) Only supports aggregation functions, not "transform" like window functions (n -> n mapping)

Both of these are left as future work. Especially, (1) needs careful thinking w.r.t. how to pass rolling window data to python efficiently. (2) is a bit easier but does require more changes therefore I think it's better to leave it as a separate PR.

## How was this patch tested?

WindowPandasUDFTests

Author: Li Jin <ice.xelloss@gmail.com>

Closes #21082 from icexelloss/SPARK-22239-window-udf.
2018-06-13 09:10:52 +08:00
edorigatti 3e5b4ae63a [SPARK-23754][PYTHON][FOLLOWUP] Move UDF stop iteration wrapping from driver to executor
## 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.
2018-06-11 10:15:42 +08:00
Tathagata Das 223df5d9d4 [SPARK-24397][PYSPARK] Added TaskContext.getLocalProperty(key) in Python
## What changes were proposed in this pull request?

This adds a new API `TaskContext.getLocalProperty(key)` to the Python TaskContext. It mirrors the Java TaskContext API of returning a string value if the key exists, or None if the key does not exist.

## How was this patch tested?
New test added.

Author: Tathagata Das <tathagata.das1565@gmail.com>

Closes #21437 from tdas/SPARK-24397.
2018-05-31 11:23:57 -07:00
Kelley Robinson 0d210ec8b6 [SPARK-24262][PYTHON] Fix typo in UDF type match error message
## What changes were proposed in this pull request?

Updates `functon` to `function`. This was called out in holdenk's PyCon 2018 conference talk. Didn't see any existing PR's for this.

holdenk happy to fix the Pandas.Series bug too but will need a bit more guidance.

Author: Kelley Robinson <krobinson@twilio.com>

Closes #21304 from robinske/master.
2018-05-13 13:19:03 -07:00
Marcelo Vanzin cc613b552e [PYSPARK] Update py4j to version 0.10.7. 2018-05-09 10:47:35 -07:00
Benjamin Peterson 7013eea11c [SPARK-23522][PYTHON] always use sys.exit over builtin exit
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.
2018-03-08 20:38:34 +09:00
Li Jin 2cb23a8f51 [SPARK-23011][SQL][PYTHON] Support alternative function form with group aggregate pandas UDF
## 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.
2018-03-08 20:29:07 +09:00
hyukjinkwon c338c8cf82 [SPARK-23352][PYTHON] Explicitly specify supported types in Pandas UDFs
## What changes were proposed in this pull request?

This PR targets to explicitly specify supported types in Pandas UDFs.
The main change here is to add a deduplicated and explicit type checking in `returnType` ahead with documenting this; however, it happened to fix multiple things.

1. Currently, we don't support `BinaryType` in Pandas UDFs, for example, see:

    ```python
    from pyspark.sql.functions import pandas_udf
    pudf = pandas_udf(lambda x: x, "binary")
    df = spark.createDataFrame([[bytearray(1)]])
    df.select(pudf("_1")).show()
    ```
    ```
    ...
    TypeError: Unsupported type in conversion to Arrow: BinaryType
    ```

    We can document this behaviour for its guide.

2. Also, the grouped aggregate Pandas UDF fails fast on `ArrayType` but seems we can support this case.

    ```python
    from pyspark.sql.functions import pandas_udf, PandasUDFType
    foo = pandas_udf(lambda v: v.mean(), 'array<double>', PandasUDFType.GROUPED_AGG)
    df = spark.range(100).selectExpr("id", "array(id) as value")
    df.groupBy("id").agg(foo("value")).show()
    ```

    ```
    ...
     NotImplementedError: ArrayType, StructType and MapType are not supported with PandasUDFType.GROUPED_AGG
    ```

3. Since we can check the return type ahead, we can fail fast before actual execution.

    ```python
    # we can fail fast at this stage because we know the schema ahead
    pandas_udf(lambda x: x, BinaryType())
    ```

## How was this patch tested?

Manually tested and unit tests for `BinaryType` and `ArrayType(...)` were added.

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #20531 from HyukjinKwon/pudf-cleanup.
2018-02-12 20:49:36 +09:00
gatorsmile 7a2ada223e [SPARK-23261][PYSPARK] Rename Pandas UDFs
## What changes were proposed in this pull request?
Rename the public APIs and names of pandas udfs.

- `PANDAS SCALAR UDF` -> `SCALAR PANDAS UDF`
- `PANDAS GROUP MAP UDF` -> `GROUPED MAP PANDAS UDF`
- `PANDAS GROUP AGG UDF` -> `GROUPED AGG PANDAS UDF`

## How was this patch tested?
The existing tests

Author: gatorsmile <gatorsmile@gmail.com>

Closes #20428 from gatorsmile/renamePandasUDFs.
2018-01-30 21:55:55 +09:00
Li Jin b2ce17b4c9 [SPARK-22274][PYTHON][SQL] User-defined aggregation functions with pandas udf (full shuffle)
## What changes were proposed in this pull request?

Add support for using pandas UDFs with groupby().agg().

This PR introduces a new type of pandas UDF - group aggregate pandas UDF. This type of UDF defines a transformation of multiple pandas Series -> a scalar value. Group aggregate pandas UDFs can be used with groupby().agg(). Note group aggregate pandas UDF doesn't support partial aggregation, i.e., a full shuffle is required.

This PR doesn't support group aggregate pandas UDFs that return ArrayType, StructType or MapType. Support for these types is left for future PR.

## How was this patch tested?

GroupbyAggPandasUDFTests

Author: Li Jin <ice.xelloss@gmail.com>

Closes #19872 from icexelloss/SPARK-22274-groupby-agg.
2018-01-23 14:11:30 +09:00
Takuya UESHIN 64817c423c [SPARK-22395][SQL][PYTHON] Fix the behavior of timestamp values for Pandas to respect session timezone
## What changes were proposed in this pull request?

When converting Pandas DataFrame/Series from/to Spark DataFrame using `toPandas()` or pandas udfs, timestamp values behave to respect Python system timezone instead of session timezone.

For example, let's say we use `"America/Los_Angeles"` as session timezone and have a timestamp value `"1970-01-01 00:00:01"` in the timezone. Btw, I'm in Japan so Python timezone would be `"Asia/Tokyo"`.

The timestamp value from current `toPandas()` will be the following:

```
>>> spark.conf.set("spark.sql.session.timeZone", "America/Los_Angeles")
>>> df = spark.createDataFrame([28801], "long").selectExpr("timestamp(value) as ts")
>>> df.show()
+-------------------+
|                 ts|
+-------------------+
|1970-01-01 00:00:01|
+-------------------+

>>> df.toPandas()
                   ts
0 1970-01-01 17:00:01
```

As you can see, the value becomes `"1970-01-01 17:00:01"` because it respects Python timezone.
As we discussed in #18664, we consider this behavior is a bug and the value should be `"1970-01-01 00:00:01"`.

## How was this patch tested?

Added tests and existing tests.

Author: Takuya UESHIN <ueshin@databricks.com>

Closes #19607 from ueshin/issues/SPARK-22395.
2017-11-28 16:45:22 +08:00
Li Jin 7d039e0c0a [SPARK-22409] Introduce function type argument in pandas_udf
## What changes were proposed in this pull request?

* Add a "function type" argument to pandas_udf.
* Add a new public enum class `PandasUdfType` in pyspark.sql.functions
* Refactor udf related code from pyspark.sql.functions to pyspark.sql.udf
* Merge "PythonUdfType" and "PythonEvalType" into a single enum class "PythonEvalType"

Example:
```
from pyspark.sql.functions import pandas_udf, PandasUDFType

pandas_udf('double', PandasUDFType.SCALAR):
def plus_one(v):
    return v + 1
```

## Design doc
https://docs.google.com/document/d/1KlLaa-xJ3oz28xlEJqXyCAHU3dwFYkFs_ixcUXrJNTc/edit

## How was this patch tested?

Added PandasUDFTests

## TODO:
* [x] Implement proper enum type for `PandasUDFType`
* [x] Update documentation
* [x] Add more tests in PandasUDFTests

Author: Li Jin <ice.xelloss@gmail.com>

Closes #19630 from icexelloss/spark-22409-pandas-udf-type.
2017-11-17 16:43:08 +01:00
Takuya UESHIN b8624b06e5 [SPARK-20396][SQL][PYSPARK][FOLLOW-UP] groupby().apply() with pandas udf
## What changes were proposed in this pull request?

This is a follow-up of #18732.
This pr modifies `GroupedData.apply()` method to convert pandas udf to grouped udf implicitly.

## How was this patch tested?

Exisiting tests.

Author: Takuya UESHIN <ueshin@databricks.com>

Closes #19517 from ueshin/issues/SPARK-20396/fup2.
2017-10-20 12:44:30 -07:00
Li Jin bfc7e1fe1a [SPARK-20396][SQL][PYSPARK] groupby().apply() with pandas udf
## What changes were proposed in this pull request?

This PR adds an apply() function on df.groupby(). apply() takes a pandas udf that is a transformation on `pandas.DataFrame` -> `pandas.DataFrame`.

Static schema
-------------------
```
schema = df.schema

pandas_udf(schema)
def normalize(df):
    df = df.assign(v1 = (df.v1 - df.v1.mean()) / df.v1.std()
    return df

df.groupBy('id').apply(normalize)
```
Dynamic schema
-----------------------
**This use case is removed from the PR and we will discuss this as a follow up. See discussion https://github.com/apache/spark/pull/18732#pullrequestreview-66583248**

Another example to use pd.DataFrame dtypes as output schema of the udf:

```
sample_df = df.filter(df.id == 1).toPandas()

def foo(df):
      ret = # Some transformation on the input pd.DataFrame
      return ret

foo_udf = pandas_udf(foo, foo(sample_df).dtypes)

df.groupBy('id').apply(foo_udf)
```
In interactive use case, user usually have a sample pd.DataFrame to test function `foo` in their notebook. Having been able to use `foo(sample_df).dtypes` frees user from specifying the output schema of `foo`.

Design doc: https://github.com/icexelloss/spark/blob/pandas-udf-doc/docs/pyspark-pandas-udf.md

## How was this patch tested?
* Added GroupbyApplyTest

Author: Li Jin <ice.xelloss@gmail.com>
Author: Takuya UESHIN <ueshin@databricks.com>
Author: Bryan Cutler <cutlerb@gmail.com>

Closes #18732 from icexelloss/groupby-apply-SPARK-20396.
2017-10-11 07:32:01 +09:00
Takuya UESHIN 09cbf3df20 [SPARK-22125][PYSPARK][SQL] Enable Arrow Stream format for vectorized UDF.
## What changes were proposed in this pull request?

Currently we use Arrow File format to communicate with Python worker when invoking vectorized UDF but we can use Arrow Stream format.

This pr replaces the Arrow File format with the Arrow Stream format.

## How was this patch tested?

Existing tests.

Author: Takuya UESHIN <ueshin@databricks.com>

Closes #19349 from ueshin/issues/SPARK-22125.
2017-09-27 23:21:44 +09:00
Bryan Cutler d8e825e3bc [SPARK-22106][PYSPARK][SQL] Disable 0-parameter pandas_udf and add doctests
## What changes were proposed in this pull request?

This change disables the use of 0-parameter pandas_udfs due to the API being overly complex and awkward, and can easily be worked around by using an index column as an input argument.  Also added doctests for pandas_udfs which revealed bugs for handling empty partitions and using the pandas_udf decorator.

## How was this patch tested?

Reworked existing 0-parameter test to verify error is raised, added doctest for pandas_udf, added new tests for empty partition and decorator usage.

Author: Bryan Cutler <cutlerb@gmail.com>

Closes #19325 from BryanCutler/arrow-pandas_udf-0-param-remove-SPARK-22106.
2017-09-26 10:54:00 +09:00
Bryan Cutler 27fc536d9a [SPARK-21190][PYSPARK] Python Vectorized UDFs
This PR adds vectorized UDFs to the Python API

**Proposed API**
Introduce a flag to turn on vectorization for a defined UDF, for example:

```
pandas_udf(DoubleType())
def plus(a, b)
    return a + b
```
or

```
plus = pandas_udf(lambda a, b: a + b, DoubleType())
```
Usage is the same as normal UDFs

0-parameter UDFs
pandas_udf functions can declare an optional `**kwargs` and when evaluated, will contain a key "size" that will give the required length of the output.  For example:

```
pandas_udf(LongType())
def f0(**kwargs):
    return pd.Series(1).repeat(kwargs["size"])

df.select(f0())
```

Added new unit tests in pyspark.sql that are enabled if pyarrow and Pandas are available.

- [x] Fix support for promoted types with null values
- [ ] Discuss 0-param UDF API (use of kwargs)
- [x] Add tests for chained UDFs
- [ ] Discuss behavior when pyarrow not installed / enabled
- [ ] Cleanup pydoc and add user docs

Author: Bryan Cutler <cutlerb@gmail.com>
Author: Takuya UESHIN <ueshin@databricks.com>

Closes #18659 from BryanCutler/arrow-vectorized-udfs-SPARK-21404.
2017-09-22 16:17:50 +08:00
Josh Rosen 8ddbc431d8 [SPARK-20685] Fix BatchPythonEvaluation bug in case of single UDF w/ repeated arg.
## What changes were proposed in this pull request?

There's a latent corner-case bug in PySpark UDF evaluation where executing a `BatchPythonEvaluation` with a single multi-argument UDF where _at least one argument value is repeated_ will crash at execution with a confusing error.

This problem was introduced in #12057: the code there has a fast path for handling a "batch UDF evaluation consisting of a single Python UDF", but that branch incorrectly assumes that a single UDF won't have repeated arguments and therefore skips the code for unpacking arguments from the input row (whose schema may not necessarily match the UDF inputs due to de-duplication of repeated arguments which occurred in the JVM before sending UDF inputs to Python).

This fix here is simply to remove this special-casing: it turns out that the code in the "multiple UDFs" branch just so happens to work for the single-UDF case because Python treats `(x)` as equivalent to `x`, not as a single-argument tuple.

## How was this patch tested?

New regression test in `pyspark.python.sql.tests` module (tested and confirmed that it fails before my fix).

Author: Josh Rosen <joshrosen@databricks.com>

Closes #17927 from JoshRosen/SPARK-20685.
2017-05-10 16:50:57 -07:00
Holden Karau 047a9d92ca [SPARK-18576][PYTHON] Add basic TaskContext information to PySpark
## What changes were proposed in this pull request?

Adds basic TaskContext information to PySpark.

## How was this patch tested?

New unit tests to `tests.py` & existing unit tests.

Author: Holden Karau <holden@us.ibm.com>

Closes #16211 from holdenk/SPARK-18576-pyspark-taskcontext.
2016-12-20 15:51:21 -08:00