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    1f29d502
    [SPARK-9812] [STREAMING] Fix Python 3 compatibility issue in PySpark Streaming and some docs · 1f29d502
    zsxwing authored
    This PR includes the following fixes:
    1. Use `range` instead of `xrange` in `queue_stream.py` to support Python 3.
    2. Fix the issue that `utf8_decoder` will return `bytes` rather than `str` when receiving an empty `bytes` in Python 3.
    3. Fix the commands in docs so that the user can copy them directly to the command line. The previous commands was broken in the middle of a path, so when copying to the command line, the path would be split to two parts by the extra spaces, which forces the user to fix it manually.
    
    Author: zsxwing <zsxwing@gmail.com>
    
    Closes #8315 from zsxwing/SPARK-9812.
    1f29d502
    History
    [SPARK-9812] [STREAMING] Fix Python 3 compatibility issue in PySpark Streaming and some docs
    zsxwing authored
    This PR includes the following fixes:
    1. Use `range` instead of `xrange` in `queue_stream.py` to support Python 3.
    2. Fix the issue that `utf8_decoder` will return `bytes` rather than `str` when receiving an empty `bytes` in Python 3.
    3. Fix the commands in docs so that the user can copy them directly to the command line. The previous commands was broken in the middle of a path, so when copying to the command line, the path would be split to two parts by the extra spaces, which forces the user to fix it manually.
    
    Author: zsxwing <zsxwing@gmail.com>
    
    Closes #8315 from zsxwing/SPARK-9812.
queue_stream.py 1.73 KiB
#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

"""
 Create a queue of RDDs that will be mapped/reduced one at a time in
 1 second intervals.

 To run this example use
    `$ bin/spark-submit examples/src/main/python/streaming/queue_stream.py
"""
import sys
import time

from pyspark import SparkContext
from pyspark.streaming import StreamingContext

if __name__ == "__main__":

    sc = SparkContext(appName="PythonStreamingQueueStream")
    ssc = StreamingContext(sc, 1)

    # Create the queue through which RDDs can be pushed to
    # a QueueInputDStream
    rddQueue = []
    for i in range(5):
        rddQueue += [ssc.sparkContext.parallelize([j for j in range(1, 1001)], 10)]

    # Create the QueueInputDStream and use it do some processing
    inputStream = ssc.queueStream(rddQueue)
    mappedStream = inputStream.map(lambda x: (x % 10, 1))
    reducedStream = mappedStream.reduceByKey(lambda a, b: a + b)
    reducedStream.pprint()

    ssc.start()
    time.sleep(6)
    ssc.stop(stopSparkContext=True, stopGraceFully=True)