[SPARK-4897] [PySpark] Python 3 support

This PR update PySpark to support Python 3 (tested with 3.4).

Known issue: unpickle array from Pyrolite is broken in Python 3, those tests are skipped.

TODO: ec2/spark-ec2.py is not fully tested with python3.

Author: Davies Liu <davies@databricks.com>
Author: twneale <twneale@gmail.com>
Author: Josh Rosen <joshrosen@databricks.com>

Closes #5173 from davies/python3 and squashes the following commits:

d7d6323 [Davies Liu] fix tests
6c52a98 [Davies Liu] fix mllib test
99e334f [Davies Liu] update timeout
b716610 [Davies Liu] Merge branch 'master' of github.com:apache/spark into python3
cafd5ec [Davies Liu] adddress comments from @mengxr
bf225d7 [Davies Liu] Merge branch 'master' of github.com:apache/spark into python3
179fc8d [Davies Liu] tuning flaky tests
8c8b957 [Davies Liu] fix ResourceWarning in Python 3
5c57c95 [Davies Liu] Merge branch 'master' of github.com:apache/spark into python3
4006829 [Davies Liu] fix test
2fc0066 [Davies Liu] add python3 path
71535e9 [Davies Liu] fix xrange and divide
5a55ab4 [Davies Liu] Merge branch 'master' of github.com:apache/spark into python3
125f12c [Davies Liu] Merge branch 'master' of github.com:apache/spark into python3
ed498c8 [Davies Liu] fix compatibility with python 3
820e649 [Davies Liu] Merge branch 'master' of github.com:apache/spark into python3
e8ce8c9 [Davies Liu] Merge branch 'master' of github.com:apache/spark into python3
ad7c374 [Davies Liu] fix mllib test and warning
ef1fc2f [Davies Liu] fix tests
4eee14a [Davies Liu] Merge branch 'master' of github.com:apache/spark into python3
20112ff [Davies Liu] Merge branch 'master' of github.com:apache/spark into python3
59bb492 [Davies Liu] fix tests
1da268c [Davies Liu] Merge branch 'master' of github.com:apache/spark into python3
ca0fdd3 [Davies Liu] fix code style
9563a15 [Davies Liu] add imap back for python 2
0b1ec04 [Davies Liu] make python examples work with Python 3
d2fd566 [Davies Liu] Merge branch 'master' of github.com:apache/spark into python3
a716d34 [Davies Liu] test with python 3.4
f1700e8 [Davies Liu] fix test in python3
671b1db [Davies Liu] fix test in python3
692ff47 [Davies Liu] fix flaky test
7b9699f [Davies Liu] invalidate import cache for Python 3.3+
9c58497 [Davies Liu] fix kill worker
309bfbf [Davies Liu] keep compatibility
5707476 [Davies Liu] cleanup, fix hash of string in 3.3+
8662d5b [Davies Liu] Merge branch 'master' of github.com:apache/spark into python3
f53e1f0 [Davies Liu] fix tests
70b6b73 [Davies Liu] compile ec2/spark_ec2.py in python 3
a39167e [Davies Liu] support customize class in __main__
814c77b [Davies Liu] run unittests with python 3
7f4476e [Davies Liu] mllib tests passed
d737924 [Davies Liu] pass ml tests
375ea17 [Davies Liu] SQL tests pass
6cc42a9 [Davies Liu] rename
431a8de [Davies Liu] streaming tests pass
78901a7 [Davies Liu] fix hash of serializer in Python 3
24b2f2e [Davies Liu] pass all RDD tests
35f48fe [Davies Liu] run future again
1eebac2 [Davies Liu] fix conflict in ec2/spark_ec2.py
6e3c21d [Davies Liu] make cloudpickle work with Python3
2fb2db3 [Josh Rosen] Guard more changes behind sys.version; still doesn't run
1aa5e8f [twneale] Turned out `pickle.DictionaryType is dict` == True, so swapped it out
7354371 [twneale] buffer --> memoryview  I'm not super sure if this a valid change, but the 2.7 docs recommend using memoryview over buffer where possible, so hoping it'll work.
b69ccdf [twneale] Uses the pure python pickle._Pickler instead of c-extension _pickle.Pickler. It appears pyspark 2.7 uses the pure python pickler as well, so this shouldn't degrade pickling performance (?).
f40d925 [twneale] xrange --> range
e104215 [twneale] Replaces 2.7 types.InstsanceType with 3.4 `object`....could be horribly wrong depending on how types.InstanceType is used elsewhere in the package--see http://bugs.python.org/issue8206
79de9d0 [twneale] Replaces python2.7 `file` with 3.4 _io.TextIOWrapper
2adb42d [Josh Rosen] Fix up some import differences between Python 2 and 3
854be27 [Josh Rosen] Run `futurize` on Python code:
7c5b4ce [Josh Rosen] Remove Python 3 check in shell.py.

6 files changed, 17 insertions, 11 deletions

diff --git a/examples/src/main/python/streaming/hdfs_wordcount.py b/examples/src/main/python/streaming/hdfs_wordcount.py
index f7ffb53796..f815dd2682 100644
--- a/examples/src/main/python/streaming/hdfs_wordcount.py
+++ b/examples/src/main/python/streaming/hdfs_wordcount.py
@@ -25,6 +25,7 @@
 
  Then create a text file in `localdir` and the words in the file will get counted.
 """
+from __future__ import print_function
 
 import sys
 
@@ -33,7 +34,7 @@ from pyspark.streaming import StreamingContext
 
 if __name__ == "__main__":
     if len(sys.argv) != 2:
-        print >> sys.stderr, "Usage: hdfs_wordcount.py <directory>"
+        print("Usage: hdfs_wordcount.py <directory>", file=sys.stderr)
         exit(-1)
 
     sc = SparkContext(appName="PythonStreamingHDFSWordCount")
diff --git a/examples/src/main/python/streaming/kafka_wordcount.py b/examples/src/main/python/streaming/kafka_wordcount.py
index 51e1ff822f..b178e7899b 100644
--- a/examples/src/main/python/streaming/kafka_wordcount.py
+++ b/examples/src/main/python/streaming/kafka_wordcount.py
@@ -27,6 +27,7 @@
       spark-streaming-kafka-assembly-*.jar examples/src/main/python/streaming/kafka_wordcount.py \
       localhost:2181 test`
 """
+from __future__ import print_function
 
 import sys
 
@@ -36,7 +37,7 @@ from pyspark.streaming.kafka import KafkaUtils
 
 if __name__ == "__main__":
     if len(sys.argv) != 3:
-        print >> sys.stderr, "Usage: kafka_wordcount.py <zk> <topic>"
+        print("Usage: kafka_wordcount.py <zk> <topic>", file=sys.stderr)
         exit(-1)
 
     sc = SparkContext(appName="PythonStreamingKafkaWordCount")
diff --git a/examples/src/main/python/streaming/network_wordcount.py b/examples/src/main/python/streaming/network_wordcount.py
index cfa9c1ff5b..2b48bcfd55 100644
--- a/examples/src/main/python/streaming/network_wordcount.py
+++ b/examples/src/main/python/streaming/network_wordcount.py
@@ -25,6 +25,7 @@
  and then run the example
     `$ bin/spark-submit examples/src/main/python/streaming/network_wordcount.py localhost 9999`
 """
+from __future__ import print_function
 
 import sys
 
@@ -33,7 +34,7 @@ from pyspark.streaming import StreamingContext
 
 if __name__ == "__main__":
     if len(sys.argv) != 3:
-        print >> sys.stderr, "Usage: network_wordcount.py <hostname> <port>"
+        print("Usage: network_wordcount.py <hostname> <port>", file=sys.stderr)
         exit(-1)
     sc = SparkContext(appName="PythonStreamingNetworkWordCount")
     ssc = StreamingContext(sc, 1)
diff --git a/examples/src/main/python/streaming/recoverable_network_wordcount.py b/examples/src/main/python/streaming/recoverable_network_wordcount.py
index fc6827c82b..ac91f0a06b 100644
--- a/examples/src/main/python/streaming/recoverable_network_wordcount.py
+++ b/examples/src/main/python/streaming/recoverable_network_wordcount.py
@@ -35,6 +35,7 @@
  checkpoint data exists in ~/checkpoint/, then it will create StreamingContext from
  the checkpoint data.
 """
+from __future__ import print_function
 
 import os
 import sys
@@ -46,7 +47,7 @@ from pyspark.streaming import StreamingContext
 def createContext(host, port, outputPath):
     # If you do not see this printed, that means the StreamingContext has been loaded
     # from the new checkpoint
-    print "Creating new context"
+    print("Creating new context")
     if os.path.exists(outputPath):
         os.remove(outputPath)
     sc = SparkContext(appName="PythonStreamingRecoverableNetworkWordCount")
@@ -60,8 +61,8 @@ def createContext(host, port, outputPath):
 
     def echo(time, rdd):
         counts = "Counts at time %s %s" % (time, rdd.collect())
-        print counts
-        print "Appending to " + os.path.abspath(outputPath)
+        print(counts)
+        print("Appending to " + os.path.abspath(outputPath))
         with open(outputPath, 'a') as f:
             f.write(counts + "\n")
 
@@ -70,8 +71,8 @@ def createContext(host, port, outputPath):
 
 if __name__ == "__main__":
     if len(sys.argv) != 5:
-        print >> sys.stderr, "Usage: recoverable_network_wordcount.py <hostname> <port> "\
-                             "<checkpoint-directory> <output-file>"
+        print("Usage: recoverable_network_wordcount.py <hostname> <port> "
+              "<checkpoint-directory> <output-file>", file=sys.stderr)
         exit(-1)
     host, port, checkpoint, output = sys.argv[1:]
     ssc = StreamingContext.getOrCreate(checkpoint,
diff --git a/examples/src/main/python/streaming/sql_network_wordcount.py b/examples/src/main/python/streaming/sql_network_wordcount.py
index f89bc562d8..da90c07dbd 100644
--- a/examples/src/main/python/streaming/sql_network_wordcount.py
+++ b/examples/src/main/python/streaming/sql_network_wordcount.py
@@ -27,6 +27,7 @@
  and then run the example
     `$ bin/spark-submit examples/src/main/python/streaming/sql_network_wordcount.py localhost 9999`
 """
+from __future__ import print_function
 
 import os
 import sys
@@ -44,7 +45,7 @@ def getSqlContextInstance(sparkContext):
 
 if __name__ == "__main__":
     if len(sys.argv) != 3:
-        print >> sys.stderr, "Usage: sql_network_wordcount.py <hostname> <port> "
+        print("Usage: sql_network_wordcount.py <hostname> <port> ", file=sys.stderr)
         exit(-1)
     host, port = sys.argv[1:]
     sc = SparkContext(appName="PythonSqlNetworkWordCount")
@@ -57,7 +58,7 @@ if __name__ == "__main__":
 
     # Convert RDDs of the words DStream to DataFrame and run SQL query
     def process(time, rdd):
-        print "========= %s =========" % str(time)
+        print("========= %s =========" % str(time))
 
         try:
             # Get the singleton instance of SQLContext
diff --git a/examples/src/main/python/streaming/stateful_network_wordcount.py b/examples/src/main/python/streaming/stateful_network_wordcount.py
index 18a9a5a452..16ef646b7c 100644
--- a/examples/src/main/python/streaming/stateful_network_wordcount.py
+++ b/examples/src/main/python/streaming/stateful_network_wordcount.py
@@ -29,6 +29,7 @@
     `$ bin/spark-submit examples/src/main/python/streaming/stateful_network_wordcount.py \
         localhost 9999`
 """
+from __future__ import print_function
 
 import sys
 
@@ -37,7 +38,7 @@ from pyspark.streaming import StreamingContext
 
 if __name__ == "__main__":
     if len(sys.argv) != 3:
-        print >> sys.stderr, "Usage: stateful_network_wordcount.py <hostname> <port>"
+        print("Usage: stateful_network_wordcount.py <hostname> <port>", file=sys.stderr)
         exit(-1)
     sc = SparkContext(appName="PythonStreamingStatefulNetworkWordCount")
     ssc = StreamingContext(sc, 1)