[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.

1 files changed, 10 insertions, 6 deletions

diff --git a/python/pyspark/worker.py b/python/pyspark/worker.py
index 452d6fabdc..fbdaf3a581 100644
--- a/python/pyspark/worker.py
+++ b/python/pyspark/worker.py
@@ -18,6 +18,7 @@
 """
 Worker that receives input from Piped RDD.
 """
+from __future__ import print_function
 import os
 import sys
 import time
@@ -37,9 +38,9 @@ utf8_deserializer = UTF8Deserializer()
 
 def report_times(outfile, boot, init, finish):
     write_int(SpecialLengths.TIMING_DATA, outfile)
-    write_long(1000 * boot, outfile)
-    write_long(1000 * init, outfile)
-    write_long(1000 * finish, outfile)
+    write_long(int(1000 * boot), outfile)
+    write_long(int(1000 * init), outfile)
+    write_long(int(1000 * finish), outfile)
 
 
 def add_path(path):
@@ -72,6 +73,9 @@ def main(infile, outfile):
         for _ in range(num_python_includes):
             filename = utf8_deserializer.loads(infile)
             add_path(os.path.join(spark_files_dir, filename))
+        if sys.version > '3':
+            import importlib
+            importlib.invalidate_caches()
 
         # fetch names and values of broadcast variables
         num_broadcast_variables = read_int(infile)
@@ -106,14 +110,14 @@ def main(infile, outfile):
     except Exception:
         try:
             write_int(SpecialLengths.PYTHON_EXCEPTION_THROWN, outfile)
-            write_with_length(traceback.format_exc(), outfile)
+            write_with_length(traceback.format_exc().encode("utf-8"), outfile)
         except IOError:
             # JVM close the socket
             pass
         except Exception:
             # Write the error to stderr if it happened while serializing
-            print >> sys.stderr, "PySpark worker failed with exception:"
-            print >> sys.stderr, traceback.format_exc()
+            print("PySpark worker failed with exception:", file=sys.stderr)
+            print(traceback.format_exc(), file=sys.stderr)
         exit(-1)
     finish_time = time.time()
     report_times(outfile, boot_time, init_time, finish_time)