一些基本信息：
- Python: 2.7
- 操作系统: Mac 10.13.2 High Sierra
- Anaconda-Navigator: 版本1.7.0
我的基本工作流程如下：
- 使用pySpark和Spark数据框架进行一些初始的数据提取和转换。
- 将Spark数据框架转换为Panda数据框架，以便使用像Seaborn这样的库进行绘图。在这里我使用函数.toPandas()，但它会抛出一个非常奇怪的错误。
例如，这是我测试过的一个非常小的Spark数据框架，它会产生与我的较大数据框架相同的错误：
sampleList = [('john', 10000.0),('sally', 3.0),('dude', 10.0)]
sparkTestDF = sqlContext.createDataFrame(sampleList, schema=['name','denominator'])
sparkTestDF.toPandas()
这将导致出现以下错误。有什么想法如何解决或避开这个问题吗？该怎么做？
Py4JJavaErrorTraceback (most recent call last)
<ipython-input-15-b151034bf9ad> in <module>()
1 sampleList = [('john', 10000.0),('sally', 3.0),('dude', 10.0)]
2 sparkTestDF = sqlContext.createDataFrame(sampleList, schema=['name','denominator'])
----> 3 sparkTestDF.toPandas()
/anaconda2/lib/python2.7/site-packages/pyspark/sql/dataframe.pyc in toPandas(self)
1964 raise RuntimeError("%s\n%s" % (_exception_message(e), msg))
1965 else:
-> 1966 pdf = pd.DataFrame.from_records(self.collect(), columns=self.columns)
1967
1968 dtype = {}
/anaconda2/lib/python2.7/site-packages/pyspark/sql/dataframe.pyc in collect(self)
464 """
465 with SCCallSiteSync(self._sc) as css:
--> 466 port = self._jdf.collectToPython()
467 return list(_load_from_socket(port, BatchedSerializer(PickleSerializer())))
468
/anaconda2/lib/python2.7/site-packages/py4j/java_gateway.pyc in __call__(self, *args)
1158 answer = self.gateway_client.send_command(command)
1159 return_value = get_return_value(
-> 1160 answer, self.gateway_client, self.target_id, self.name)
1161
1162 for temp_arg in temp_args:
/anaconda2/lib/python2.7/site-packages/pyspark/sql/utils.pyc in deco(*a, **kw)
61 def deco(*a, **kw):
62 try:
---> 63 return f(*a, **kw)
64 except py4j.protocol.Py4JJavaError as e:
65 s = e.java_exception.toString()
/anaconda2/lib/python2.7/site-packages/py4j/protocol.pyc in get_return_value(answer, gateway_client, target_id, name)
318 raise Py4JJavaError(
319 "An error occurred while calling {0}{1}{2}.\n".
--> 320 format(target_id, ".", name), value)
321 else:
322 raise Py4JError(
Py4JJavaError: An error occurred while calling o155.collectToPython.
: java.lang.IllegalArgumentException
at org.apache.xbean.asm5.ClassReader.<init>(Unknown Source)
at org.apache.xbean.asm5.ClassReader.<init>(Unknown Source)
at org.apache.xbean.asm5.ClassReader.<init>(Unknown Source)
at org.apache.spark.util.ClosureCleaner$.getClassReader(ClosureCleaner.scala:46)
at org.apache.spark.util.FieldAccessFinder$$anon$3$$anonfun$visitMethodInsn$2.apply(ClosureCleaner.scala:449)
at org.apache.spark.util.FieldAccessFinder$$anon$3$$anonfun$visitMethodInsn$2.apply(ClosureCleaner.scala:432)
at scala.collection.TraversableLike$WithFilter$$anonfun$foreach$1.apply(TraversableLike.scala:733)
at scala.collection.mutable.HashMap$$anon$1$$anonfun$foreach$2.apply(HashMap.scala:103)
at scala.collection.mutable.HashMap$$anon$1$$anonfun$foreach$2.apply(HashMap.scala:103)
at scala.collection.mutable.HashTable$class.foreachEntry(HashTable.scala:230)
at scala.collection.mutable.HashMap.foreachEntry(HashMap.scala:40)
at scala.collection.mutable.HashMap$$anon$1.foreach(HashMap.scala:103)
at scala.collection.TraversableLike$WithFilter.foreach(TraversableLike.scala:732)
at org.apache.spark.util.FieldAccessFinder$$anon$3.visitMethodInsn(ClosureCleaner.scala:432)
at org.apache.xbean.asm5.ClassReader.a(Unknown Source)
at org.apache.xbean.asm5.ClassReader.b(Unknown Source)
at org.apache.xbean.asm5.ClassReader.accept(Unknown Source)
at org.apache.xbean.asm5.ClassReader.accept(Unknown Source)
at org.apache.spark.util.ClosureCleaner$$anonfun$org$apache$spark$util$ClosureCleaner$$clean$14.apply(ClosureCleaner.scala:262)
at org.apache.spark.util.ClosureCleaner$$anonfun$org$apache$spark$util$ClosureCleaner$$clean$14.apply(ClosureCleaner.scala:261)
at scala.collection.immutable.List.foreach(List.scala:381)
at org.apache.spark.util.ClosureCleaner$.org$apache$spark$util$ClosureCleaner$$clean(ClosureCleaner.scala:261)
at org.apache.spark.util.ClosureCleaner$.clean(ClosureCleaner.scala:159)
at org.apache.spark.SparkContext.clean(SparkContext.scala:2292)
at org.apache.spark.SparkContext.runJob(SparkContext.scala:2066)
at org.apache.spark.SparkContext.runJob(SparkContext.scala:2092)
at org.apache.spark.rdd.RDD$$anonfun$collect$1.apply(RDD.scala:939)
at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:151)
at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:112)
at org.apache.spark.rdd.RDD.withScope(RDD.scala:363)
at org.apache.spark.rdd.RDD.collect(RDD.scala:938)
at org.apache.spark.sql.execution.SparkPlan.executeCollect(SparkPlan.scala:297)
at org.apache.spark.sql.Dataset$$anonfun$collectToPython$1.apply$mcI$sp(Dataset.scala:3195)
at org.apache.spark.sql.Dataset$$anonfun$collectToPython$1.apply(Dataset.scala:3192)
at org.apache.spark.sql.Dataset$$anonfun$collectToPython$1.apply(Dataset.scala:3192)
at org.apache.spark.sql.execution.SQLExecution$.withNewExecutionId(SQLExecution.scala:77)
at org.apache.spark.sql.Dataset.withNewExecutionId(Dataset.scala:3225)
at org.apache.spark.sql.Dataset.collectToPython(Dataset.scala:3192)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:244)
at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:357)
at py4j.Gateway.invoke(Gateway.java:282)
at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
at py4j.commands.CallCommand.execute(CallCommand.java:79)
at py4j.GatewayConnection.run(GatewayConnection.java:214)
at java.base/java.lang.Thread.run(Thread.java:844)
spark_submit调用的一部分运行时，可以比较环境设置与在 conda 环境中运行它时的设置。我曾经遇到过相同类型的错误消息（即使show能够正常工作，但collect却不能），并注意到系统路径和环境变量之间存在令人启迪的差异。 - Oliver W.