Run flake8 in Travis and make code PEP8 compliant. (#387)

python/ray/workers/default_worker.py

@@ -3,25 +3,33 @@ from __future__ import division
 from __future__ import print_function
 
 import argparse
+import binascii
 import numpy as np
 import redis
 import traceback
-import sys
-import binascii
 
 import ray
 
-parser = argparse.ArgumentParser(description="Parse addresses for the worker to connect to.")
-parser.add_argument("--node-ip-address", required=True, type=str, help="the ip address of the worker's node")
-parser.add_argument("--redis-address", required=True, type=str, help="the address to use for Redis")
-parser.add_argument("--object-store-name", required=True, type=str, help="the object store's name")
-parser.add_argument("--object-store-manager-name", required=True, type=str, help="the object store manager's name")
-parser.add_argument("--local-scheduler-name", required=True, type=str, help="the local scheduler's name")
-parser.add_argument("--actor-id", required=False, type=str, help="the actor ID of this worker")
+parser = argparse.ArgumentParser(description=("Parse addresses for the worker "
+                                              "to connect to."))
+parser.add_argument("--node-ip-address", required=True, type=str,
+                    help="the ip address of the worker's node")
+parser.add_argument("--redis-address", required=True, type=str,
+                    help="the address to use for Redis")
+parser.add_argument("--object-store-name", required=True, type=str,
+                    help="the object store's name")
+parser.add_argument("--object-store-manager-name", required=True, type=str,
+                    help="the object store manager's name")
+parser.add_argument("--local-scheduler-name", required=True, type=str,
+                    help="the local scheduler's name")
+parser.add_argument("--actor-id", required=False, type=str,
+                    help="the actor ID of this worker")
+
 
 def random_string():
   return np.random.bytes(20)
 
+
 if __name__ == "__main__":
   args = parser.parse_args()
   info = {"node_ip_address": args.node_ip_address,
@@ -30,7 +38,10 @@ if __name__ == "__main__":
           "manager_socket_name": args.object_store_manager_name,
           "local_scheduler_socket_name": args.local_scheduler_name}
 
-  actor_id = binascii.unhexlify(args.actor_id) if not args.actor_id is None else ray.worker.NIL_ACTOR_ID
+  if args.actor_id is not None:
+    actor_id = binascii.unhexlify(args.actor_id)
+  else:
+    actor_id = ray.worker.NIL_ACTOR_ID
 
   ray.worker.connect(info, mode=ray.WORKER_MODE, actor_id=actor_id)
 
@@ -43,24 +54,27 @@ being caught in "python/ray/workers/default_worker.py".
   while True:
     try:
       # This call to main_loop should never return if things are working. Most
-      # exceptions that are thrown (e.g., inside the execution of a task) should
-      # be caught and handled inside of the call to main_loop. If an exception
-      # is thrown here, then that means that there is some error that we didn't
-      # anticipate.
+      # exceptions that are thrown (e.g., inside the execution of a task)
+      # should be caught and handled inside of the call to main_loop. If an
+      # exception is thrown here, then that means that there is some error that
+      # we didn't anticipate.
       ray.worker.main_loop()
     except Exception as e:
       traceback_str = traceback.format_exc() + error_explanation
       DRIVER_ID_LENGTH = 20
-      # We use a driver ID of all zeros to push an error message to all drivers.
+      # We use a driver ID of all zeros to push an error message to all
+      # drivers.
       driver_id = DRIVER_ID_LENGTH * b"\x00"
       error_key = b"Error:" + driver_id + b":" + random_string()
       redis_ip_address, redis_port = args.redis_address.split(":")
       # For this command to work, some other client (on the same machine as
       # Redis) must have run "CONFIG SET protected-mode no".
-      redis_client = redis.StrictRedis(host=redis_ip_address, port=int(redis_port))
+      redis_client = redis.StrictRedis(host=redis_ip_address,
+                                       port=int(redis_port))
       redis_client.hmset(error_key, {"type": "worker_crash",
                                      "message": traceback_str,
-                                     "note": "This error is unexpected and should not have happened."})
+                                     "note": ("This error is unexpected and "
+                                              "should not have happened.")})
       redis_client.rpush("ErrorKeys", error_key)
       # TODO(rkn): Note that if the worker was in the middle of executing a
       # task, the any worker or driver that is blocking in a get call and