[SPARK-19002][BUILD][PYTHON] Check pep8 against all Python scripts

## What changes were proposed in this pull request?

This PR proposes to check pep8 against all other Python scripts and fix the errors as below:

```bash
./dev/create-release/generate-contributors.py
./dev/create-release/releaseutils.py
./dev/create-release/translate-contributors.py
./dev/lint-python
./python/docs/epytext.py
./examples/src/main/python/mllib/decision_tree_classification_example.py
./examples/src/main/python/mllib/decision_tree_regression_example.py
./examples/src/main/python/mllib/gradient_boosting_classification_example.py
./examples/src/main/python/mllib/gradient_boosting_regression_example.py
./examples/src/main/python/mllib/linear_regression_with_sgd_example.py
./examples/src/main/python/mllib/logistic_regression_with_lbfgs_example.py
./examples/src/main/python/mllib/naive_bayes_example.py
./examples/src/main/python/mllib/random_forest_classification_example.py
./examples/src/main/python/mllib/random_forest_regression_example.py
./examples/src/main/python/mllib/svm_with_sgd_example.py
./examples/src/main/python/streaming/network_wordjoinsentiments.py
./sql/hive/src/test/resources/data/scripts/cat.py
./sql/hive/src/test/resources/data/scripts/cat_error.py
./sql/hive/src/test/resources/data/scripts/doubleescapedtab.py
./sql/hive/src/test/resources/data/scripts/dumpdata_script.py
./sql/hive/src/test/resources/data/scripts/escapedcarriagereturn.py
./sql/hive/src/test/resources/data/scripts/escapednewline.py
./sql/hive/src/test/resources/data/scripts/escapedtab.py
./sql/hive/src/test/resources/data/scripts/input20_script.py
./sql/hive/src/test/resources/data/scripts/newline.py
```

## How was this patch tested?

- `./python/docs/epytext.py`

  ```bash
  cd ./python/docs $$ make html
  ```

- pep8 check (Python 2.7 / Python 3.3.6)

  ```
  ./dev/lint-python
  ```

- `./dev/merge_spark_pr.py` (Python 2.7 only / Python 3.3.6 not working)

  ```bash
  python -m doctest -v ./dev/merge_spark_pr.py
  ```

- `./dev/create-release/releaseutils.py` `./dev/create-release/generate-contributors.py` `./dev/create-release/translate-contributors.py` (Python 2.7 only / Python 3.3.6 not working)

  ```bash
  python generate-contributors.py
  python translate-contributors.py
  ```

- Examples (Python 2.7 / Python 3.3.6)

  ```bash
  ./bin/spark-submit examples/src/main/python/mllib/decision_tree_classification_example.py
  ./bin/spark-submit examples/src/main/python/mllib/decision_tree_regression_example.py
  ./bin/spark-submit examples/src/main/python/mllib/gradient_boosting_classification_example.py
  ./bin/spark-submit examples/src/main/python/mllib/gradient_boosting_regression_example.p
  ./bin/spark-submit examples/src/main/python/mllib/random_forest_classification_example.py
  ./bin/spark-submit examples/src/main/python/mllib/random_forest_regression_example.py
  ```

- Examples (Python 2.7 only / Python 3.3.6 not working)
  ```
  ./bin/spark-submit examples/src/main/python/mllib/linear_regression_with_sgd_example.py
  ./bin/spark-submit examples/src/main/python/mllib/logistic_regression_with_lbfgs_example.py
  ./bin/spark-submit examples/src/main/python/mllib/naive_bayes_example.py
  ./bin/spark-submit examples/src/main/python/mllib/svm_with_sgd_example.py
  ```

- `sql/hive/src/test/resources/data/scripts/*.py` (Python 2.7 / Python 3.3.6 within suggested changes)

  Manually tested only changed ones.

- `./dev/github_jira_sync.py` (Python 2.7 only / Python 3.3.6 not working)

  Manually tested this after disabling actually adding comments and links.

And also via Jenkins tests.

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #16405 from HyukjinKwon/minor-pep8.

1 files changed, 3 insertions, 0 deletions

diff --git a/python/docs/epytext.py b/python/docs/epytext.py
index e884d5e6b1..4bbbf650a1 100644
--- a/python/docs/epytext.py
+++ b/python/docs/epytext.py
@@ -9,6 +9,7 @@ RULES = (
     ('pyspark.rdd.RDD', 'RDD'),
 )
 
+
 def _convert_epytext(line):
     """
     >>> _convert_epytext("L{A}")
@@ -19,9 +20,11 @@ def _convert_epytext(line):
         line = re.sub(p, sub, line)
     return line
 
+
 def _process_docstring(app, what, name, obj, options, lines):
     for i in range(len(lines)):
         lines[i] = _convert_epytext(lines[i])
 
+
 def setup(app):
     app.connect("autodoc-process-docstring", _process_docstring)