[SPARK-12634][Python][MLlib][DOC] Update param descriptions for tree.py

[vijaykiran]

Updates the param descriptions, in mllib/tree.py, to be consistent. See [SPARK-11219] for
more details.

[thunterdb]

@vijaykiran thanks for the style fixes.

cc @jkbradley

[jkbradley]

I just added a note to the parent JIRA about a formatting issue affecting all 5 PRs: [https://issues.apache.org/jira/browse/SPARK-11219?focusedCommentId=15090225&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-15090225]
Could you please check it out & ping when I should review again? Thank you!

[vijaykiran]

Ping @jkbradley / @BryanCutler

[BryanCutler]

"Training dataset:" should be on the next line

[BryanCutler]

Thanks @vijaykiran , this is looking much better! I made a few comments for correction, and could you also update the PR title and description to indicate that this is for tree.py?

[vijaykiran]

@BryanCutler ping! Can you check one more time ? returns are styled now.

[BryanCutler]

LGTM, ping @jkbradley

[mengxr]

ok to test

[SparkQA]

Test build #50150 has finished for PR 10601 at commit 36be47c.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[mengxr]

@vijaykiran Could you fix the doc build warnings in tree.py? I saw the following by running make clean html under python/docs:

/Users/meng/src/spark/python/pyspark/mllib/tree.py:docstring of pyspark.mllib.tree.RandomForest.trainClassifier:18: ERROR: Unexpected indentation.
/Users/meng/src/spark/python/pyspark/mllib/tree.py:docstring of pyspark.mllib.tree.RandomForest.trainClassifier:20: WARNING: Block quote ends without a blank line; unexpected unindent.
/Users/meng/src/spark/python/pyspark/mllib/tree.py:docstring of pyspark.mllib.tree.RandomForest.trainRegressor:15: ERROR: Unexpected indentation.
/Users/meng/src/spark/python/pyspark/mllib/tree.py:docstring of pyspark.mllib.tree.RandomForest.trainRegressor:17: WARNING: Block quote ends without a blank line; unexpected unindent.

[BryanCutler]

the numClasses param got put in with the previous description