Error while using mapPartitions in Pyspark - apache-spark

Question

I am new to Python spark and I am running the below spark code in the Jupyter notebook and getting AttributeError: 'NoneType' object has no attribute '_jvm'
My spark version is 3.0.1.
from pyspark.sql import functions as func
one_through_9 = range(1,10)
parallel = sc.parallelize(one_through_9, 3)
def f(iterator): yield func.sum(iterator)
parallel.mapPartitions(f).collect()
Find below the full error while running the code.
---------------------------------------------------------------------------
Py4JJavaError Traceback (most recent call last)
<ipython-input-55-44576a0dc413> in <module>
2 def valueSum(f): return func.sum(f)
3
----> 4 mapp.mapPartitions(valueSum).collect()
5 #one_through_9 = range(1,10)
6 #parallel = sc.parallelize(one_through_9, 3)
~/spark-3.0.1-bin-hadoop2.7/python/pyspark/rdd.py in collect(self)
887 """
888 with SCCallSiteSync(self.context) as css:
--> 889 sock_info = self.ctx._jvm.PythonRDD.collectAndServe(self._jrdd.rdd())
890 return list(_load_from_socket(sock_info, self._jrdd_deserializer))
891
~/spark-3.0.1-bin-hadoop2.7/python/lib/py4j-0.10.9-src.zip/py4j/java_gateway.py in __call__(self, *args)
1302
1303 answer = self.gateway_client.send_command(command)
-> 1304 return_value = get_return_value(
1305 answer, self.gateway_client, self.target_id, self.name)
1306
~/spark-3.0.1-bin-hadoop2.7/python/pyspark/sql/utils.py in deco(*a, **kw)
126 def deco(*a, **kw):
127 try:
--> 128 return f(*a, **kw)
129 except py4j.protocol.Py4JJavaError as e:
130 converted = convert_exception(e.java_exception)
~/spark-3.0.1-bin-hadoop2.7/python/lib/py4j-0.10.9-src.zip/py4j/protocol.py in get_return_value(answer, gateway_client, target_id, name)
324 value = OUTPUT_CONVERTER[type](answer[2:], gateway_client)
325 if answer[1] == REFERENCE_TYPE:
--> 326 raise Py4JJavaError(
327 "An error occurred while calling {0}{1}{2}.\n".
328 format(target_id, ".", name), value)
Py4JJavaError: An error occurred while calling z:org.apache.spark.api.python.PythonRDD.collectAndServe.
: org.apache.spark.SparkException: Job aborted due to stage failure: Task 0 in stage 53.0 failed 1 times, most recent failure: Lost task 0.0 in stage 53.0 (TID 83, 192.168.43.228, executor driver): org.apache.spark.api.python.PythonException: Traceback (most recent call last):
File "/home/vijee/spark-3.0.1-bin-hadoop2.7/python/lib/pyspark.zip/pyspark/worker.py", line 605, in main
process()
File "/home/vijee/spark-3.0.1-bin-hadoop2.7/python/lib/pyspark.zip/pyspark/worker.py", line 595, in process
out_iter = func(split_index, iterator)
File "/home/vijee/spark-3.0.1-bin-hadoop2.7/python/pyspark/rdd.py", line 425, in func
return f(iterator)
File "<ipython-input-55-44576a0dc413>", line 2, in valueSum
File "/home/vijee/spark-3.0.1-bin-hadoop2.7/python/lib/pyspark.zip/pyspark/sql/functions.py", line 68, in _
jc = getattr(sc._jvm.functions, name)(_to_java_column(col))
AttributeError: 'NoneType' object has no attribute '_jvm'

Answer 1

func.sum is for use with dataframes, not for summing numbers. Use the Python sum function instead:
one_through_9 = range(1,10)
parallel = sc.parallelize(one_through_9, 3)
def f(iterator):
yield sum(iterator)
parallel.mapPartitions(f).collect()
which will give [6, 15, 24].