Lint Python files with Yapf (ray-project#1872)

.style.yapf

@@ -42,7 +42,7 @@ blank_line_before_nested_class_or_def=False
 #        'key1': 'value1',
 #        'key2': 'value2',
 #    })
-coalesce_brackets=False
+coalesce_brackets=True
 
 # The column limit.
 column_limit=79
@@ -90,7 +90,7 @@ i18n_function_call=
 #       'key2': value1 +
 #               value2,
 #   }
-indent_dictionary_value=False
+indent_dictionary_value=True
 
 # The number of columns to use for indentation.
 indent_width=4
@@ -187,4 +187,3 @@ split_penalty_logical_operator=300
 
 # Use the Tab character for indentation.
 use_tabs=False
-

.travis.yml

@@ -38,10 +38,12 @@ matrix:
         - export PATH="$HOME/miniconda/bin:$PATH"
         - cd doc
         - pip install -q -r requirements-doc.txt
+        - pip install yapf
         - sphinx-build -W -b html -d _build/doctrees source _build/html
         - cd ..
         # Run Python linting.
         - flake8 --exclude=python/ray/core/src/common/flatbuffers_ep-prefix/,python/ray/core/generated/,src/common/format/,doc/source/conf.py,python/ray/cloudpickle/
+        - .travis/yapf.sh
 
     - os: linux
       dist: trusty

.travis/yapf.sh

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+
+# Cause the script to exit if a single command fails
+set -e
+
+ROOT_DIR=$(cd "$(dirname "${BASH_SOURCE:-$0}")"; pwd)
+
+pushd $ROOT_DIR/../test
+  find . -name '*.py' -type f -exec yapf --style=pep8 -i -r {} \;
+popd
+
+pushd $ROOT_DIR/../python
+  find . -name '*.py' -type f -not -path './ray/dataframe/*' -not -path './ray/rllib/*' -not -path './ray/cloudpickle/*' -exec yapf --style=pep8 -i -r {} \;
+popd
+
+CHANGED_FILES=(`git diff --name-only`)
+if [ "$CHANGED_FILES" ]; then
+  echo 'Reformatted staged files. Please review and stage the changes.'
+  echo
+  echo 'Files updated:'
+  for file in ${CHANGED_FILES[@]}; do
+    echo "  $file"
+  done
+  exit 1
+else
+  exit 0
+fi

python/ray/__init__.py

@@ -12,8 +12,8 @@
 
 # Add the directory containing pyarrow to the Python path so that we find the
 # pyarrow version packaged with ray and not a pre-existing pyarrow.
-pyarrow_path = os.path.join(os.path.abspath(os.path.dirname(__file__)),
-                            "pyarrow_files")
+pyarrow_path = os.path.join(
+    os.path.abspath(os.path.dirname(__file__)), "pyarrow_files")
 sys.path.insert(0, pyarrow_path)
 
 # See https://github.com/ray-project/ray/issues/131.
@@ -27,29 +27,29 @@
 try:
     import pyarrow  # noqa: F401
 except ImportError as e:
-    if ((hasattr(e, "msg") and isinstance(e.msg, str) and
-            ("libstdc++" in e.msg or "CXX" in e.msg))):
+    if ((hasattr(e, "msg") and isinstance(e.msg, str)
+         and ("libstdc++" in e.msg or "CXX" in e.msg))):
         # This code path should be taken with Python 3.
         e.msg += helpful_message
-    elif (hasattr(e, "message") and isinstance(e.message, str) and
-          ("libstdc++" in e.message or "CXX" in e.message)):
+    elif (hasattr(e, "message") and isinstance(e.message, str)
+          and ("libstdc++" in e.message or "CXX" in e.message)):
         # This code path should be taken with Python 2.
-        condition = (hasattr(e, "args") and isinstance(e.args, tuple) and
-                     len(e.args) == 1 and isinstance(e.args[0], str))
+        condition = (hasattr(e, "args") and isinstance(e.args, tuple)
+                     and len(e.args) == 1 and isinstance(e.args[0], str))
         if condition:
-            e.args = (e.args[0] + helpful_message,)
+            e.args = (e.args[0] + helpful_message, )
         else:
             if not hasattr(e, "args"):
                 e.args = ()
             elif not isinstance(e.args, tuple):
-                e.args = (e.args,)
-            e.args += (helpful_message,)
+                e.args = (e.args, )
+            e.args += (helpful_message, )
     raise
 
 from ray.local_scheduler import _config  # noqa: E402
-from ray.worker import (error_info, init, connect, disconnect,
-                        get, put, wait, remote, log_event, log_span,
-                        flush_log, get_gpu_ids, get_webui_url,
+from ray.worker import (error_info, init, connect, disconnect, get, put, wait,
+                        remote, log_event, log_span, flush_log, get_gpu_ids,
+                        get_webui_url,
                         register_custom_serializer)  # noqa: E402
 from ray.worker import (SCRIPT_MODE, WORKER_MODE, PYTHON_MODE,
                         SILENT_MODE)  # noqa: E402
@@ -63,11 +63,13 @@
 # Fix this.
 __version__ = "0.4.0"
 
-__all__ = ["error_info", "init", "connect", "disconnect", "get", "put", "wait",
-           "remote", "log_event", "log_span", "flush_log", "actor", "method",
-           "get_gpu_ids", "get_webui_url", "register_custom_serializer",
-           "SCRIPT_MODE", "WORKER_MODE", "PYTHON_MODE", "SILENT_MODE",
-           "global_state", "_config", "__version__"]
+__all__ = [
+    "error_info", "init", "connect", "disconnect", "get", "put", "wait",
+    "remote", "log_event", "log_span", "flush_log", "actor", "method",
+    "get_gpu_ids", "get_webui_url", "register_custom_serializer",
+    "SCRIPT_MODE", "WORKER_MODE", "PYTHON_MODE", "SILENT_MODE", "global_state",
+    "_config", "__version__"
+]
 
 import ctypes  # noqa: E402
 # Windows only