## What changes were proposed in this pull request?
PySpark StringIndexer supports StringOrderType added in #17879.

Author: Wayne Zhang <actuaryzhang@uber.com>

Closes #17978 from actuaryzhang/PythonStringIndexer.

## What changes were proposed in this pull request?
Review new Scala APIs introduced in 2.2.

## How was this patch tested?
Existing tests.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #17934 from yanboliang/spark-20501.

## What changes were proposed in this pull request?
Before 2.2, MLlib keep to remove APIs deprecated in last feature/minor release. But from Spark 2.2, we decide to remove deprecated APIs in a major release, so we need to change corresponding annotations to tell users those will be removed in 3.0.
Meanwhile, this fixed bugs in ML documents. The original ML docs can't show deprecated annotations in ```MLWriter``` and ```MLReader``` related class, we correct it in this PR.

Before:
![image](https://cloud.githubusercontent.com/assets/1962026/25939889/f8c55f20-3666-11e7-9fa2-0605bfb3ed06.png)

After:
![image](https://cloud.githubusercontent.com/assets/1962026/25939870/e9b0d5be-3666-11e7-9765-5e04885e4b32.png)

## How was this patch tested?
Existing tests.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #17946 from yanboliang/spark-20707.

[SPARK-20639][SQL] Add single argument support for to_timestamp in SQL with documentation improvement

## What changes were proposed in this pull request?

This PR proposes three things as below:

- Use casting rules to a timestamp in `to_timestamp` by default (it was `yyyy-MM-dd HH:mm:ss`).

- Support single argument for `to_timestamp` similarly with APIs in other languages.

  For example, the one below works

  ```
  import org.apache.spark.sql.functions._
  Seq("2016-12-31 00:12:00.00").toDF("a").select(to_timestamp(col("a"))).show()
  ```

  prints

  ```
  +----------------------------------------+
  |to_timestamp(`a`, 'yyyy-MM-dd HH:mm:ss')|
  +----------------------------------------+
  |                     2016-12-31 00:12:00|
  +----------------------------------------+
  ```

  whereas this does not work in SQL.

  **Before**

  ```
  spark-sql> SELECT to_timestamp('2016-12-31 00:12:00');
  Error in query: Invalid number of arguments for function to_timestamp; line 1 pos 7
  ```

  **After**

  ```
  spark-sql> SELECT to_timestamp('2016-12-31 00:12:00');
  2016-12-31 00:12:00
  ```

- Related document improvement for SQL function descriptions and other API descriptions accordingly.

  **Before**

  ```
  spark-sql> DESCRIBE FUNCTION extended to_date;
  ...
  Usage: to_date(date_str, fmt) - Parses the `left` expression with the `fmt` expression. Returns null with invalid input.
  Extended Usage:
      Examples:
        > SELECT to_date('2016-12-31', 'yyyy-MM-dd');
         2016-12-31
  ```

  ```
  spark-sql> DESCRIBE FUNCTION extended to_timestamp;
  ...
  Usage: to_timestamp(timestamp, fmt) - Parses the `left` expression with the `format` expression to a timestamp. Returns null with invalid input.
  Extended Usage:
      Examples:
        > SELECT to_timestamp('2016-12-31', 'yyyy-MM-dd');
         2016-12-31 00:00:00.0
  ```

  **After**

  ```
  spark-sql> DESCRIBE FUNCTION extended to_date;
  ...
  Usage:
      to_date(date_str[, fmt]) - Parses the `date_str` expression with the `fmt` expression to
        a date. Returns null with invalid input. By default, it follows casting rules to a date if
        the `fmt` is omitted.

  Extended Usage:
      Examples:
        > SELECT to_date('2009-07-30 04:17:52');
         2009-07-30
        > SELECT to_date('2016-12-31', 'yyyy-MM-dd');
         2016-12-31
  ```

  ```
  spark-sql> DESCRIBE FUNCTION extended to_timestamp;
  ...
   Usage:
      to_timestamp(timestamp[, fmt]) - Parses the `timestamp` expression with the `fmt` expression to
        a timestamp. Returns null with invalid input. By default, it follows casting rules to
        a timestamp if the `fmt` is omitted.

  Extended Usage:
      Examples:
        > SELECT to_timestamp('2016-12-31 00:12:00');
         2016-12-31 00:12:00
        > SELECT to_timestamp('2016-12-31', 'yyyy-MM-dd');
         2016-12-31 00:00:00
  ```

## How was this patch tested?

Added tests in `datetime.sql`.

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #17901 from HyukjinKwon/to_timestamp_arg.

## What changes were proposed in this pull request?
This pr supported a DDL-formatted string in `DataFrameReader.schema`.
This fix could make users easily define a schema without importing  `o.a.spark.sql.types._`.

## How was this patch tested?
Added tests in `DataFrameReaderWriterSuite`.

Author: Takeshi Yamamuro <yamamuro@apache.org>

Closes #17719 from maropu/SPARK-20431.

This reverts commit b8733e0a.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #17944 from yanboliang/spark-20606-revert.

## 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.

## What changes were proposed in this pull request?

It turns out pyspark doctest is calling saveAsTable without ever dropping them. Since we have separate python tests for bucketed table, and there is no checking of results, there is really no need to run the doctest, other than leaving it as an example in the generated doc

## How was this patch tested?

Jenkins

Author: Felix Cheung <felixcheung_m@hotmail.com>

Closes #17932 from felixcheung/pytablecleanup.

[SPARK-20631][PYTHON][ML] LogisticRegression._checkThresholdConsistency should use values not Params

## What changes were proposed in this pull request?

- Replace `getParam` calls with `getOrDefault` calls.
- Fix exception message to avoid unintended `TypeError`.
- Add unit tests

## How was this patch tested?

New unit tests.

Author: zero323 <zero323@users.noreply.github.com>

Closes #17891 from zero323/SPARK-20631.

## What changes were proposed in this pull request?
Remove ML methods we deprecated in 2.1.

## How was this patch tested?
Existing tests.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #17867 from yanboliang/spark-20606.

## What changes were proposed in this pull request?

Adds Python wrappers for `DataFrameWriter.bucketBy` and `DataFrameWriter.sortBy` ([SPARK-16931](https://issues.apache.org/jira/browse/SPARK-16931))

## How was this patch tested?

Unit tests covering new feature.

__Note__: Based on work of GregBowyer (f49b9a23468f7af32cb53d2b654272757c151725)

CC HyukjinKwon

Author: zero323 <zero323@users.noreply.github.com>
Author: Greg Bowyer <gbowyer@fastmail.co.uk>

Closes #17077 from zero323/SPARK-16931.

## What changes were proposed in this pull request?

- Move udf wrapping code from `functions.udf` to `functions.UserDefinedFunction`.
- Return wrapped udf from `catalog.registerFunction` and dependent methods.
- Update docstrings in `catalog.registerFunction` and `SQLContext.registerFunction`.
- Unit tests.

## How was this patch tested?

- Existing unit tests and docstests.
- Additional tests covering new feature.

Author: zero323 <zero323@users.noreply.github.com>

Closes #17831 from zero323/SPARK-18777.

## What changes were proposed in this pull request?

Adds `hint` method to PySpark `DataFrame`.

## How was this patch tested?

Unit tests, doctests.

Author: zero323 <zero323@users.noreply.github.com>

Closes #17850 from zero323/SPARK-20584.

## What changes were proposed in this pull request?

Use midpoints for split values now, and maybe later to make it weighted.

## How was this patch tested?

+ [x] add unit test.
+ [x] revise Split's unit test.

Author: Yan Facai (颜发才) <facai.yan@gmail.com>
Author: 颜发才（Yan Facai） <facai.yan@gmail.com>

Closes #17556 from facaiy/ENH/decision_tree_overflow_and_precision_in_aggregation.

Add PCA and SVD to PySpark's wrappers for `RowMatrix` and `IndexedRowMatrix` (SVD only).

Based on #7963, updated.

## How was this patch tested?

New doc tests and unit tests. Ran all examples locally.

Author: MechCoder <manojkumarsivaraj334@gmail.com>
Author: Nick Pentreath <nickp@za.ibm.com>

Closes #17621 from MLnick/SPARK-6227-pyspark-svd-pca.

Add Python API for `ALSModel` methods `recommendForAllUsers`, `recommendForAllItems`

## How was this patch tested?

New doc tests.

Author: Nick Pentreath <nickp@za.ibm.com>

Closes #17622 from MLnick/SPARK-20300-pyspark-recall.

## What changes were proposed in this pull request?

Adds Python bindings for `Column.eqNullSafe`

## How was this patch tested?

Manual tests, existing unit tests, doc build.

Author: zero323 <zero323@users.noreply.github.com>

Closes #17605 from zero323/SPARK-20290.

## What changes were proposed in this pull request?

Currently pyspark Dataframe.fillna API supports boolean type when we pass dict, but it is missing in documentation.

## How was this patch tested?
>>> spark.createDataFrame([Row(a=True),Row(a=None)]).fillna({"a" : True}).show()
+----+
|   a|
+----+
|true|
|true|
+----+

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

Author: Srinivasa Reddy Vundela <vsr@cloudera.com>

Closes #17688 from vundela/fillna_doc_fix.

## What changes were proposed in this pull request?

This PR proposes to fill up the documentation with examples for `bitwiseOR`, `bitwiseAND`, `bitwiseXOR`. `contains`, `asc` and `desc` in `Column` API.

Also, this PR fixes minor typos in the documentation and matches some of the contents between Scala doc and Python doc.

Lastly, this PR suggests to use `spark` rather than `sc` in doc tests in `Column` for Python documentation.

## How was this patch tested?

Doc tests were added and manually tested with the commands below:

`./python/run-tests.py --module pyspark-sql`
`./python/run-tests.py --module pyspark-sql --python-executable python3`
`./dev/lint-python`

Output was checked via `make html` under `./python/docs`. The snapshots will be left on the codes with comments.

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #17737 from HyukjinKwon/SPARK-20442.

## What changes were proposed in this pull request?
This pr added a new display mode for `Dataset.show` to print output rows vertically (one line per column value). In the current master, when printing Dataset with many columns, the readability is low like;

```
scala> val df = spark.range(100).selectExpr((0 until 100).map(i => s"rand() AS c$i"): _*)
scala> df.show(3, 0)
+------------------+------------------+------------------+-------------------+------------------+------------------+-------------------+------------------+------------------+------------------+------------------+-------------------+------------------+------------------+------------------+-------------------+-------------------+-------------------+------------------+------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+--------------------+-------------------+------------------+-------------------+--------------------+------------------+------------------+-------------------+-------------------+-------------------+------------------+------------------+-------------------+------------------+------------------+-------------------+-------------------+-------------------+------------------+--------------------+--------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+--------------------+-------------------+-------------------+-------------------+-------------------+------------------+------------------+-------------------+-------------------+------------------+-------------------+------------------+------------------+-----------------+-------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+------------------+-------------------+-------------------+------------------+------------------+------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+
|c0                |c1                |c2                |c3                 |c4                |c5                |c6                 |c7                |c8                |c9                |c10               |c11                |c12               |c13               |c14               |c15                |c16                |c17                |c18               |c19               |c20                |c21               |c22                |c23               |c24                |c25                |c26                |c27                 |c28                |c29               |c30                |c31                 |c32               |c33               |c34                |c35                |c36                |c37               |c38               |c39                |c40               |c41               |c42                |c43                |c44                |c45               |c46                 |c47                 |c48                |c49                |c50                |c51                |c52                |c53                |c54                 |c55                |c56                |c57                |c58                |c59               |c60               |c61                |c62                |c63               |c64                |c65               |c66               |c67              |c68                |c69                |c70               |c71                |c72               |c73                |c74                |c75                |c76               |c77                |c78               |c79                |c80                |c81                |c82                |c83                |c84                |c85                |c86                |c87               |c88                |c89                |c90               |c91               |c92               |c93                |c94               |c95                |c96               |c97                |c98                |c99                |
+------------------+------------------+------------------+-------------------+------------------+------------------+-------------------+------------------+------------------+------------------+------------------+-------------------+------------------+------------------+------------------+-------------------+-------------------+-------------------+------------------+------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+--------------------+-------------------+------------------+-------------------+--------------------+------------------+------------------+-------------------+-------------------+-------------------+------------------+------------------+-------------------+------------------+------------------+-------------------+-------------------+-------------------+------------------+--------------------+--------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+--------------------+-------------------+-------------------+-------------------+-------------------+------------------+------------------+-------------------+-------------------+------------------+-------------------+------------------+------------------+-----------------+-------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+------------------+-------------------+-------------------+------------------+------------------+------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+
|0.6306087152476858|0.9174349686288383|0.5511324165035159|0.3320844128641819 |0.7738486877101489|0.2154915886962553|0.4754997600674299 |0.922780639280355 |0.7136894772661909|0.2277580838165979|0.5926874459847249|0.40311408392226633|0.467830264333843 |0.8330466896984213|0.1893258482389527|0.6320849515511165 |0.7530911056912044 |0.06700254871955424|0.370528597355559 |0.2755437445193154|0.23704391110980128|0.8067400174905822|0.13597793616251852|0.1708888820162453|0.01672725007605702|0.983118121881555  |0.25040195628629924|0.060537253723083384|0.20000530582637488|0.3400572407133511|0.9375689433322597 |0.057039316954370256|0.8053269714347623|0.5247817572228813|0.28419308820527944|0.9798908885194533 |0.31805988175678146|0.7034448027077574|0.5400575751346084|0.25336322371116216|0.9361634546853429|0.6118681368289798|0.6295081549153907 |0.13417468943957422|0.41617137072255794|0.7267230869252035|0.023792726137561115|0.5776157058356362  |0.04884204913195467|0.26728716103441275|0.646680370807925  |0.9782712690657244 |0.16434031314818154|0.20985522381321275|0.24739842475440077 |0.26335189682977334|0.19604841662422068|0.10742950487300651|0.20283136488091502|0.3100312319723688|0.886959006630645 |0.25157102269776244|0.34428775168410786|0.3500506818575777|0.3781142441912052 |0.8560316444386715|0.4737104888956839|0.735903101602148|0.02236617130529006|0.8769074095835873 |0.2001426662503153|0.5534032319238532 |0.7289496620397098|0.41955191309992157|0.9337700133660436 |0.34059094378451005|0.6419144759403556|0.08167496930341167|0.9947099478497635|0.48010888605366586|0.22314796858167918|0.17786598882331306|0.7351521162297135 |0.5422057170020095 |0.9521927872726792 |0.7459825486368227 |0.40907708791990627|0.8903819313311575|0.7251413746923618 |0.2977174938745204 |0.9515209660203555|0.9375968604766713|0.5087851740042524|0.4255237544908751 |0.8023768698664653|0.48003189618006703|0.1775841829745185|0.09050775629268382|0.6743909291138167 |0.2498415755876865 |
|0.6866473844170801|0.4774360641212433|0.631696201340726 |0.33979113021468343|0.5663049010847052|0.7280190472258865|0.41370958502324806|0.9977433873622218|0.7671957338989901|0.2788708556233931|0.3355106391656496|0.88478952319287   |0.0333974166999893|0.6061744715862606|0.9617779139652359|0.22484954822341863|0.12770906021550898|0.5577789629508672 |0.2877649024640704|0.5566577406549361|0.9334933255278052 |0.9166720585157266|0.9689249324600591 |0.6367502457478598|0.7993572745928459 |0.23213222324218108|0.11928284054154137|0.6173493362456599  |0.0505122058694798 |0.9050228629552983|0.17112767911121707|0.47395598348370005 |0.5820498657823081|0.6241124650645072|0.18587258258036776|0.14987593554122225|0.3079446253653946 |0.9414228822867968|0.8362276265462365|0.9155655305576353 |0.5121559807153562|0.8963362656525707|0.22765970274318037|0.8177039187132797 |0.8190326635933787 |0.5256005177032199|0.8167598457269669  |0.030936807130934496|0.6733006585281015 |0.4208049626816347 |0.24603085738518538|0.22719198954208153|0.1622280557565281 |0.22217325159218038|0.014684419513742553|0.08987111517447499|0.2157764759142622 |0.8223414104088321 |0.4868624404491777 |0.4016191733088167|0.6169281906889263|0.15603611040433385|0.18289285085714913|0.9538408988218972|0.15037154865295121|0.5364516961987454|0.8077254873163031|0.712600478545675|0.7277477241003857 |0.19822912960348305|0.8305051199208777|0.18631911396566114|0.8909532487898342|0.3470409226992506 |0.35306974180587636|0.9107058868891469 |0.3321327206004986|0.48952332459050607|0.3630403307479373|0.5400046826340376 |0.5387377194310529 |0.42860539421837585|0.23214101630985995|0.21438968839794847|0.15370603160082352|0.04355605642700022|0.6096006707067466 |0.6933354157094292|0.06302172470859002|0.03174631856164001|0.664243581650643 |0.7833239547446621|0.696884598352864 |0.34626385933237736|0.9263495598791336|0.404818892816584  |0.2085585394755507|0.6150004897990109 |0.05391193524302473|0.28188484028329097|
+------------------+------------------+------------------+-------------------+------------------+------------------+-------------------+------------------+------------------+------------------+------------------+-------------------+------------------+------------------+------------------+-------------------+-------------------+-------------------+------------------+------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+--------------------+-------------------+------------------+-------------------+--------------------+------------------+------------------+-------------------+-------------------+-------------------+------------------+------------------+-------------------+------------------+------------------+-------------------+-------------------+-------------------+------------------+--------------------+--------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+--------------------+-------------------+-------------------+-------------------+-------------------+------------------+------------------+-------------------+-------------------+------------------+-------------------+------------------+------------------+-----------------+-------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+-------------------+------------------+-------------------+-------------------+------------------+------------------+------------------+-------------------+------------------+-------------------+------------------+-------------------+-------------------+-------------------+
only showing top 2 rows
```

`psql`, CLI for PostgreSQL, supports a vertical display mode for this case like:
http://stackoverflow.com/questions/9604723/alternate-output-format-for-psql

```
-RECORD 0-------------------
 c0  | 0.6306087152476858
 c1  | 0.9174349686288383
 c2  | 0.5511324165035159
...
 c98 | 0.05391193524302473
 c99 | 0.28188484028329097
-RECORD 1-------------------
 c0  | 0.6866473844170801
 c1  | 0.4774360641212433
 c2  | 0.631696201340726
...
 c98 | 0.05391193524302473
 c99 | 0.28188484028329097
only showing top 2 rows
```

## How was this patch tested?
Added tests in `DataFrameSuite`.

Author: Takeshi Yamamuro <yamamuro@apache.org>

Closes #17733 from maropu/SPARK-20425.

## What changes were proposed in this pull request?
Some PySpark & SparkR tests run with tiny dataset and tiny ```maxIter```, which means they are not converged. I don’t think checking intermediate result during iteration make sense, and these intermediate result may vulnerable and not stable, so we should switch to check the converged result. We hit this issue at #17746 when we upgrade breeze to 0.13.1.

## How was this patch tested?
Existing tests.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #17757 from yanboliang/flaky-test.

## What changes were proposed in this pull request?
Upgrade breeze version to 0.13.1, which fixed some critical bugs of L-BFGS-B.

## How was this patch tested?
Existing unit tests.

Author: Yanbo Liang <ybliang8@gmail.com>

Closes #17746 from yanboliang/spark-20449.

## What changes were proposed in this pull request?
Add docstrings to column.py for the Column functions `rlike`, `like`, `startswith`, and `endswith`. Pass these docstrings through `_bin_op`

There may be a better place to put the docstrings. I put them immediately above the Column class.

## How was this patch tested?

I ran `make html` on my local computer to remake the documentation, and verified that the html pages were displaying the docstrings correctly. I tried running `dev-tests`, and the formatting tests passed. However, my mvn build didn't work I think due to issues on my computer.

These docstrings are my original work and free license.

davies has done the most recent work reorganizing `_bin_op`

Author: Michael Patterson <map222@gmail.com>

Closes #17469 from map222/patterson-documentation.

## What changes were proposed in this pull request?

Establishes a very minimal `_repr_html_` for PySpark's `SparkContext`.

## How was this patch tested?

nteract:

![screen shot 2017-04-17 at 3 41 29 pm](https://cloud.githubusercontent.com/assets/836375/25107701/d57090ba-2385-11e7-8147-74bc2c50a41b.png)

Jupyter:

![screen shot 2017-04-17 at 3 53 19 pm](https://cloud.githubusercontent.com/assets/836375/25107725/05bf1fe8-2386-11e7-93e1-07a20c917dde.png)

Hydrogen:

![screen shot 2017-04-17 at 3 49 55 pm](https://cloud.githubusercontent.com/assets/836375/25107664/a75e1ddc-2385-11e7-8477-258661833007.png)

Author: Kyle Kelley <rgbkrk@gmail.com>

Closes #17662 from rgbkrk/repr.

## What changes were proposed in this pull request?

Improve combineByKey documentation:

* Add note on memory allocation
* Change example code to use different mergeValue and mergeCombiners

## How was this patch tested?

Doctest.

## 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 #17545 from dgingrich/topic-spark-20232-combinebykey-docs.

## What changes were proposed in this pull request?

SPARK-15236 do this for scala shell, this ticket is for pyspark shell. This is not only for pyspark itself, but can also benefit downstream project like livy which use shell.py for its interactive session. For now, livy has no control of whether enable hive or not.

## How was this patch tested?

I didn't find a way to add test for it. Just manually test it.
Run `bin/pyspark --master local --conf spark.sql.catalogImplementation=in-memory` and verify hive is not enabled.

Author: Jeff Zhang <zjffdu@apache.org>

Closes #16906 from zjffdu/SPARK-19570.

## What changes were proposed in this pull request?

This PR proposes corrections related to JSON APIs as below:

- Rendering links in Python documentation
- Replacing `RDD` to `Dataset` in programing guide
- Adding missing description about JSON Lines consistently in `DataFrameReader.json` in Python API
- De-duplicating little bit of `DataFrameReader.json` in Scala/Java API

## How was this patch tested?

Manually build the documentation via `jekyll build`. Corresponding snapstops will be left on the codes.

Note that currently there are Javadoc8 breaks in several places. These are proposed to be handled in https://github.com/apache/spark/pull/17477. So, this PR does not fix those.

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #17602 from HyukjinKwon/minor-json-documentation.

## 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.

## What changes were proposed in this pull request?

Saw the following failure locally:

```
Traceback (most recent call last):
  File "/home/jenkins/workspace/python/pyspark/streaming/tests.py", line 351, in test_cogroup
    self._test_func(input, func, expected, sort=True, input2=input2)
  File "/home/jenkins/workspace/python/pyspark/streaming/tests.py", line 162, in _test_func
    self.assertEqual(expected, result)
AssertionError: Lists differ: [[(1, ([1], [2])), (2, ([1], [... != []

First list contains 3 additional elements.
First extra element 0:
[(1, ([1], [2])), (2, ([1], [])), (3, ([1], []))]

+ []
- [[(1, ([1], [2])), (2, ([1], [])), (3, ([1], []))],
-  [(1, ([1, 1, 1], [])), (2, ([1], [])), (4, ([], [1]))],
-  [('', ([1, 1], [1, 2])), ('a', ([1, 1], [1, 1])), ('b', ([1], [1]))]]
```

It also happened on Jenkins: http://spark-tests.appspot.com/builds/spark-branch-2.1-test-sbt-hadoop-2.7/120

It's because when the machine is overloaded, the timeout is not enough. This PR just increases the timeout to 30 seconds.

## How was this patch tested?

Jenkins

Author: Shixiong Zhu <shixiong@databricks.com>

Closes #17597 from zsxwing/SPARK-20285.

## What changes were proposed in this pull request?

The Dataframes-based support for the correlation statistics is added in #17108. This patch adds the Python interface for it.

## How was this patch tested?

Python unit test.

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

Author: Liang-Chi Hsieh <viirya@gmail.com>

Closes #17494 from viirya/correlation-python-api.

[SPARK-20196][PYTHON][SQL] update doc for catalog functions for all languages, add pyspark refreshByPath API

## What changes were proposed in this pull request?

Update doc to remove external for createTable, add refreshByPath in python

## How was this patch tested?

manual

Author: Felix Cheung <felixcheung_m@hotmail.com>

Closes #17512 from felixcheung/catalogdoc.

## What changes were proposed in this pull request?
PySpark version in version.py was lagging behind
Versioning is  in line with PEP 440: https://www.python.org/dev/peps/pep-0440/

## How was this patch tested?
Simply rebuild the project with existing tests

Author: setjet <rubenljanssen@gmail.com>
Author: Ruben Janssen <rubenljanssen@gmail.com>

Closes #17523 from setjet/SPARK-20064.

## What changes were proposed in this pull request?

`_convert_to_vector` converts a scipy sparse matrix to csc matrix for initializing `SparseVector`. However, it doesn't guarantee the converted csc matrix has sorted indices and so a failure happens when you do something like that:

    from scipy.sparse import lil_matrix
    lil = lil_matrix((4, 1))
    lil[1, 0] = 1
    lil[3, 0] = 2
    _convert_to_vector(lil.todok())

    File "/home/jenkins/workspace/python/pyspark/mllib/linalg/__init__.py", line 78, in _convert_to_vector
      return SparseVector(l.shape[0], csc.indices, csc.data)
    File "/home/jenkins/workspace/python/pyspark/mllib/linalg/__init__.py", line 556, in __init__
      % (self.indices[i], self.indices[i + 1]))
    TypeError: Indices 3 and 1 are not strictly increasing

A simple test can confirm that `dok_matrix.tocsc()` won't guarantee sorted indices:

    >>> from scipy.sparse import lil_matrix
    >>> lil = lil_matrix((4, 1))
    >>> lil[1, 0] = 1
    >>> lil[3, 0] = 2
    >>> dok = lil.todok()
    >>> csc = dok.tocsc()
    >>> csc.has_sorted_indices
    0
    >>> csc.indices
    array([3, 1], dtype=int32)

I checked the source codes of scipy. The only way to guarantee it is `csc_matrix.tocsr()` and `csr_matrix.tocsc()`.

## How was this patch tested?

Existing tests.

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

Author: Liang-Chi Hsieh <viirya@gmail.com>

Closes #17532 from viirya/make-sure-sorted-indices.

## What changes were proposed in this pull request?

- Allows skipping `value` argument if `to_replace` is a `dict`:
	```python
	df = sc.parallelize([("Alice", 1, 3.0)]).toDF()
	df.replace({"Alice": "Bob"}).show()
	````
- Adds validation step to ensure homogeneous values / replacements.
- Simplifies internal control flow.
- Improves unit tests coverage.

## How was this patch tested?

Existing unit tests, additional unit tests, manual testing.

Author: zero323 <zero323@users.noreply.github.com>

Closes #16793 from zero323/SPARK-19454.

[SPARK-20166][SQL] Use XXX for ISO 8601 timezone instead of ZZ (FastDateFormat specific) in CSV/JSON timeformat options

## What changes were proposed in this pull request?

This PR proposes to use `XXX` format instead of `ZZ`. `ZZ` seems a `FastDateFormat` specific.

`ZZ` supports "ISO 8601 extended format time zones" but it seems `FastDateFormat` specific option.
I misunderstood this is compatible format with `SimpleDateFormat` when this change is introduced.
Please see [SimpleDateFormat documentation]( https://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html#iso8601timezone) and [FastDateFormat documentation](https://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/time/FastDateFormat.html).

It seems we better replace `ZZ` to `XXX` because they look using the same strategy - [FastDateParser.java#L930](https://github.com/apache/commons-lang/blob/8767cd4f1a6af07093c1e6c422dae8e574be7e5e/src/main/java/org/apache/commons/lang3/time/FastDateParser.java#L930), [FastDateParser.java#L932-L951 ](https://github.com/apache/commons-lang/blob/8767cd4f1a6af07093c1e6c422dae8e574be7e5e/src/main/java/org/apache/commons/lang3/time/FastDateParser.java#L932-L951) and [FastDateParser.java#L596-L601](https://github.com/apache/commons-lang/blob/8767cd4f1a6af07093c1e6c422dae8e574be7e5e/src/main/java/org/apache/commons/lang3/time/FastDateParser.java#L596-L601).

I also checked the codes and manually debugged it for sure. It seems both cases use the same pattern `( Z|(?:[+-]\\d{2}(?::)\\d{2}))`.

_Note that this should be rather a fix about documentation and not the behaviour change because `ZZ` seems invalid date format in `SimpleDateFormat` as documented in `DataFrameReader` and etc, and both `ZZ` and `XXX` look identically working with `FastDateFormat`_

Current documentation is as below:

```
   * <li>`timestampFormat` (default `yyyy-MM-dd'T'HH:mm:ss.SSSZZ`): sets the string that
   * indicates a timestamp format. Custom date formats follow the formats at
   * `java.text.SimpleDateFormat`. This applies to timestamp type.</li>
```

## How was this patch tested?

Existing tests should cover this. Also, manually tested as below (BTW, I don't think these are worth being added as tests within Spark):

**Parse**

```scala
scala> new java.text.SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX").parse("2017-03-21T00:00:00.000-11:00")
res4: java.util.Date = Tue Mar 21 20:00:00 KST 2017

scala>  new java.text.SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX").parse("2017-03-21T00:00:00.000Z")
res10: java.util.Date = Tue Mar 21 09:00:00 KST 2017

scala> new java.text.SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZZ").parse("2017-03-21T00:00:00.000-11:00")
java.text.ParseException: Unparseable date: "2017-03-21T00:00:00.000-11:00"
  at java.text.DateFormat.parse(DateFormat.java:366)
  ... 48 elided
scala>  new java.text.SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZZ").parse("2017-03-21T00:00:00.000Z")
java.text.ParseException: Unparseable date: "2017-03-21T00:00:00.000Z"
  at java.text.DateFormat.parse(DateFormat.java:366)
  ... 48 elided
```

```scala
scala> org.apache.commons.lang3.time.FastDateFormat.getInstance("yyyy-MM-dd'T'HH:mm:ss.SSSXXX").parse("2017-03-21T00:00:00.000-11:00")
res7: java.util.Date = Tue Mar 21 20:00:00 KST 2017

scala> org.apache.commons.lang3.time.FastDateFormat.getInstance("yyyy-MM-dd'T'HH:mm:ss.SSSXXX").parse("2017-03-21T00:00:00.000Z")
res1: java.util.Date = Tue Mar 21 09:00:00 KST 2017

scala> org.apache.commons.lang3.time.FastDateFormat.getInstance("yyyy-MM-dd'T'HH:mm:ss.SSSZZ").parse("2017-03-21T00:00:00.000-11:00")
res8: java.util.Date = Tue Mar 21 20:00:00 KST 2017

scala> org.apache.commons.lang3.time.FastDateFormat.getInstance("yyyy-MM-dd'T'HH:mm:ss.SSSZZ").parse("2017-03-21T00:00:00.000Z")
res2: java.util.Date = Tue Mar 21 09:00:00 KST 2017
```

**Format**

```scala
scala> new java.text.SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX").format(new java.text.SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX").parse("2017-03-21T00:00:00.000-11:00"))
res6: String = 2017-03-21T20:00:00.000+09:00
```

```scala
scala> val fd = org.apache.commons.lang3.time.FastDateFormat.getInstance("yyyy-MM-dd'T'HH:mm:ss.SSSZZ")
fd: org.apache.commons.lang3.time.FastDateFormat = FastDateFormat[yyyy-MM-dd'T'HH:mm:ss.SSSZZ,ko_KR,Asia/Seoul]

scala> fd.format(fd.parse("2017-03-21T00:00:00.000-11:00"))
res1: String = 2017-03-21T20:00:00.000+09:00

scala> val fd = org.apache.commons.lang3.time.FastDateFormat.getInstance("yyyy-MM-dd'T'HH:mm:ss.SSSXXX")
fd: org.apache.commons.lang3.time.FastDateFormat = FastDateFormat[yyyy-MM-dd'T'HH:mm:ss.SSSXXX,ko_KR,Asia/Seoul]

scala> fd.format(fd.parse("2017-03-21T00:00:00.000-11:00"))
res2: String = 2017-03-21T20:00:00.000+09:00
```

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #17489 from HyukjinKwon/SPARK-20166.

## What changes were proposed in this pull request?

Allow Jenkins Python tests to use the installed conda to test Python 2.7 support & test pip installability.

## How was this patch tested?

Updated shell scripts, ran tests locally with installed conda, ran tests in Jenkins.

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

Closes #17355 from holdenk/SPARK-19955-support-python-tests-with-conda.

## What changes were proposed in this pull request?

A pyspark wrapper for spark.ml.stat.ChiSquareTest

## How was this patch tested?

unit tests
doctests

Author: Bago Amirbekian <bago@databricks.com>

Closes #17421 from MrBago/chiSquareTestWrapper.

## What changes were proposed in this pull request?

The master snapshot publisher builds are currently broken due to two minor build issues:

1. For unknown reasons, the LFTP `mkdir -p` command began throwing errors when the remote directory already exists. This change of behavior might have been caused by configuration changes in the ASF's SFTP server, but I'm not entirely sure of that. To work around this problem, this patch updates the script to ignore errors from the `lftp mkdir -p` commands.
2. The PySpark `setup.py` file references a non-existent `pyspark.ml.stat` module, causing Python packaging to fail by complaining about a missing directory. The fix is to simply drop that line from the setup script.

## How was this patch tested?

The LFTP fix was tested by manually running the failing commands on AMPLab Jenkins against the ASF SFTP server. The PySpark fix was tested locally.

Author: Josh Rosen <joshrosen@databricks.com>

Closes #17437 from JoshRosen/spark-20102.

## What changes were proposed in this pull request?

This PR proposes to match minor documentations changes in https://github.com/apache/spark/pull/17399 and https://github.com/apache/spark/pull/17380 to R/Python.

## How was this patch tested?

Manual tests in Python , Python tests via `./python/run-tests.py --module=pyspark-sql` and lint-checks for Python/R.

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #17429 from HyukjinKwon/minor-match-doc.

## What changes were proposed in this pull request?

- Add `HasSupport` and `HasConfidence` `Params`.
- Add new module `pyspark.ml.fpm`.
- Add `FPGrowth` / `FPGrowthModel` wrappers.
- Provide tests for new features.

## How was this patch tested?

Unit tests.

Author: zero323 <zero323@users.noreply.github.com>

Closes #17218 from zero323/SPARK-19281.