2016-03-30 7 views
0

私は 'all_tweets'という名前のSQLデータフレームを持っていますが、これには1つの列テキストしかありません。pipeline RDDでflatMap()を使用するには?

all_tweets.show(5) 

+--------------------+ 
|    text| 
+--------------------+ 
|@always_nidhi @Yo...| 
|@OnlyDancers Bell...| 
|Taste of Iceland!...| 
|Serasi ade haha @...| 
|@BeezyDH_ it's li...| 
+--------------------+ 
only showing top 5 rows 

ここでは、このデータフレームをRDDに変換して、変換とアクションを実行しています。

[I] all_twt_rdd = all_tweets.rdd 

[I] type(all_twt_rdd) 

[O] pyspark.rdd.RDD 

[I] all_twt_rdd.first() 

[O] Row(text=u'@always_nidhi @YouTube no i dnt understand bt i loved the music nd their dance awesome all the song of this mve is rocking') 

ここで、文章を単語に分割するためにflatMapを実行しようとしています。

[I] user_cnt = all_twt_rdd.flatMap(lambda line: line.split(" ")).take(5) 

上記を実行すると、以下のエラーが発生します。 RDDにはデータがあります。しかし、私はなぜそれがエラーを理解していない。パイプライン化されていないRDDはRDDの機能を継承していますか?

[O] 
Py4JJavaError        Traceback (most recent call last) 
<ipython-input-101-31527190732e> in <module>() 
----> 1 user_cnt = all_twt_rdd.flatMap(lambda line: line.split(" ")).take(2) 

/home/notebook/spark-1.6.0-bin-hadoop2.6/python/pyspark/rdd.pyc in take(self, num) 
    1295 
    1296    p = range(partsScanned, min(partsScanned + numPartsToTry, totalParts)) 
-> 1297    res = self.context.runJob(self, takeUpToNumLeft, p) 
    1298 
    1299    items += res 

/home/notebook/spark-1.6.0-bin-hadoop2.6/python/pyspark/context.pyc in runJob(self, rdd, partitionFunc, partitions, allowLocal) 
    937   # SparkContext#runJob. 
    938   mappedRDD = rdd.mapPartitions(partitionFunc) 
--> 939   port = self._jvm.PythonRDD.runJob(self._jsc.sc(), mappedRDD._jrdd, partitions) 
    940   return list(_load_from_socket(port, mappedRDD._jrdd_deserializer)) 
    941 

/home/notebook/spark-1.6.0-bin-hadoop2.6/python/lib/py4j-0.9-src.zip/py4j/java_gateway.py in __call__(self, *args) 
    811   answer = self.gateway_client.send_command(command) 
    812   return_value = get_return_value(
--> 813    answer, self.gateway_client, self.target_id, self.name) 
    814 
    815   for temp_arg in temp_args: 

/home/notebook/spark-1.6.0-bin-hadoop2.6/python/pyspark/sql/utils.pyc in deco(*a, **kw) 
    43  def deco(*a, **kw): 
    44   try: 
---> 45    return f(*a, **kw) 
    46   except py4j.protocol.Py4JJavaError as e: 
    47    s = e.java_exception.toString() 

/home/notebook/spark-1.6.0-bin-hadoop2.6/python/lib/py4j-0.9-src.zip/py4j/protocol.py in get_return_value(answer, gateway_client, target_id, name) 
    306     raise Py4JJavaError(
    307      "An error occurred while calling {0}{1}{2}.\n". 
--> 308      format(target_id, ".", name), value) 
    309    else: 
    310     raise Py4JError(

Py4JJavaError: An error occurred while calling z:org.apache.spark.api.python.PythonRDD.runJob. 
: org.apache.spark.SparkException: Job aborted due to stage failure: Task 0 in stage 50.0 failed 1 times, most recent failure: Lost task 0.0 in stage 50.0 (TID 456, localhost): org.apache.spark.api.python.PythonException: Traceback (most recent call last): 
    File "/home/notebook/spark-1.6.0-bin-hadoop2.6/python/lib/pyspark.zip/pyspark/worker.py", line 111, in main 
    process() 
    File "/home/notebook/spark-1.6.0-bin-hadoop2.6/python/lib/pyspark.zip/pyspark/worker.py", line 106, in process 
    serializer.dump_stream(func(split_index, iterator), outfile) 
    File "/home/notebook/spark-1.6.0-bin-hadoop2.6/python/lib/pyspark.zip/pyspark/serializers.py", line 263, in dump_stream 
    vs = list(itertools.islice(iterator, batch)) 
    File "/home/notebook/spark-1.6.0-bin-hadoop2.6/python/pyspark/rdd.py", line 1293, in takeUpToNumLeft 
    yield next(iterator) 
    File "<ipython-input-101-31527190732e>", line 1, in <lambda> 
    File "/home/notebook/spark-1.6.0-bin-hadoop2.6/python/lib/pyspark.zip/pyspark/sql/types.py", line 1272, in __getattr__ 
    raise AttributeError(item) 
AttributeError: split 

    at org.apache.spark.api.python.PythonRunner$$anon$1.read(PythonRDD.scala:166) 
    at org.apache.spark.api.python.PythonRunner$$anon$1.<init>(PythonRDD.scala:207) 
    at org.apache.spark.api.python.PythonRunner.compute(PythonRDD.scala:125) 
    at org.apache.spark.api.python.PythonRDD.compute(PythonRDD.scala:70) 
    at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:306) 
    at org.apache.spark.rdd.RDD.iterator(RDD.scala:270) 
    at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:66) 
    at org.apache.spark.scheduler.Task.run(Task.scala:89) 
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:213) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) 
    at java.lang.Thread.run(Thread.java:745) 

Driver stacktrace: 
    at org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:1431) 
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1419) 
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1418) 
    at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59) 
    at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47) 
    at org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:1418) 
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:799) 
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:799) 
    at scala.Option.foreach(Option.scala:236) 
    at org.apache.spark.scheduler.DAGScheduler.handleTaskSetFailed(DAGScheduler.scala:799) 
    at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.doOnReceive(DAGScheduler.scala:1640) 
    at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1599) 
    at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1588) 
    at org.apache.spark.util.EventLoop$$anon$1.run(EventLoop.scala:48) 
    at org.apache.spark.scheduler.DAGScheduler.runJob(DAGScheduler.scala:620) 
    at org.apache.spark.SparkContext.runJob(SparkContext.scala:1832) 
    at org.apache.spark.SparkContext.runJob(SparkContext.scala:1845) 
    at org.apache.spark.SparkContext.runJob(SparkContext.scala:1858) 
    at org.apache.spark.api.python.PythonRDD$.runJob(PythonRDD.scala:393) 
    at org.apache.spark.api.python.PythonRDD.runJob(PythonRDD.scala) 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
    at java.lang.reflect.Method.invoke(Method.java:606) 
    at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:231) 
    at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:381) 
    at py4j.Gateway.invoke(Gateway.java:259) 
    at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:133) 
    at py4j.commands.CallCommand.execute(CallCommand.java:79) 
    at py4j.GatewayConnection.run(GatewayConnection.java:209) 
    at java.lang.Thread.run(Thread.java:745) 
Caused by: org.apache.spark.api.python.PythonException: Traceback (most recent call last): 
    File "/home/notebook/spark-1.6.0-bin-hadoop2.6/python/lib/pyspark.zip/pyspark/worker.py", line 111, in main 
    process() 
    File "/home/notebook/spark-1.6.0-bin-hadoop2.6/python/lib/pyspark.zip/pyspark/worker.py", line 106, in process 
    serializer.dump_stream(func(split_index, iterator), outfile) 
    File "/home/notebook/spark-1.6.0-bin-hadoop2.6/python/lib/pyspark.zip/pyspark/serializers.py", line 263, in dump_stream 
    vs = list(itertools.islice(iterator, batch)) 
    File "/home/notebook/spark-1.6.0-bin-hadoop2.6/python/pyspark/rdd.py", line 1293, in takeUpToNumLeft 
    yield next(iterator) 
    File "<ipython-input-101-31527190732e>", line 1, in <lambda> 
    File "/home/notebook/spark-1.6.0-bin-hadoop2.6/python/lib/pyspark.zip/pyspark/sql/types.py", line 1272, in __getattr__ 
    raise AttributeError(item) 
AttributeError: split 

    at org.apache.spark.api.python.PythonRunner$$anon$1.read(PythonRDD.scala:166) 
    at org.apache.spark.api.python.PythonRunner$$anon$1.<init>(PythonRDD.scala:207) 
    at org.apache.spark.api.python.PythonRunner.compute(PythonRDD.scala:125) 
    at org.apache.spark.api.python.PythonRDD.compute(PythonRDD.scala:70) 
    at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:306) 
    at org.apache.spark.rdd.RDD.iterator(RDD.scala:270) 
    at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:66) 
    at org.apache.spark.scheduler.Task.run(Task.scala:89) 
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:213) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) 
    ... 1 more 
+0

あなたは 'Row'オブジェクトに対して' split'を呼び出しています。しかし、 'Row'は' split'メソッドを定義していません。 –

+0

'' lambda line:line.text.split( "") 'を実行してみてください。 –

答えて

2

問題は、文字列、に.split()をいない呼び出しているということです。行オブジェクトには.split()メソッドがありません。文字列だけが行います。 text属性を分割したいので、明示的に呼び出してください。

user_cnt = all_twt_rdd.flatMap(lambda line: line.text.split(" ")).take(5) 
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