AttributeError: 'NoneType' object has no attribute 'sc'

Question

Excuse me.Today i want to run a program about how to create DataFrame with sqlContext in Pyspark.The result is a AttributeError,which is"AttributeError: 'NoneType' object has no attribute 'sc'" My computer is win7,spark's version is 1.6.0 ,and API is python3 .I had google several times and read the Spark Python API Docs,and can not solved the problems.So i look for your help.

my code is that:

   #python version is 3.5
   sc.stop()
   import pandas as pd
   import numpy as np
   sc=SparkContext("local","app1"
   data2=[("a",5),("b",5),("a",5)]
   df=sqlContext.createDataFrame(data2)

And the result is that:

---

    AttributeError                            Traceback (most recent call last)
    <ipython-input-19-030b8faadb2c> in <module>()
    5 data2=[("a",5),("b",5),("a",5)]
    6 print(data2)
    ----> 7 df=sqlContext.createDataFrame(data2)

    D:\spark\spark-1.6.0-bin-hadoop2.6\python\pyspark\sql\context.py in  createDataFrame(self, data, schema, samplingRatio)
    426             rdd, schema = self._createFromRDD(data, schema, samplingRatio)
    427         else:
    --> 428             rdd, schema = self._createFromLocal(data, schema)
    429         jrdd = self._jvm.SerDeUtil.toJavaArray(rdd._to_java_object_rdd())
    430         jdf = self._ssql_ctx.applySchemaToPythonRDD(jrdd.rdd(), schema.json())

    D:\spark\spark-1.6.0-bin-hadoop2.6\python\pyspark\sql\context.py in _createFromLocal(self, data, schema)
   358         # convert python objects to sql data
   359         data = [schema.toInternal(row) for row in data]
   --> 360         return self._sc.parallelize(data), schema
   361 
   362     @since(1.3)

    D:\spark\spark-1.6.0-bin-hadoop2.6\python\pyspark\context.py in parallelize(self, c, numSlices)
   410         [[], [0], [], [2], [4]]
   411         """
   --> 412         numSlices = int(numSlices) if numSlices is not None else self.defaultParallelism
   413         if isinstance(c, xrange):
   414             size = len(c)

   D:\spark\spark-1.6.0-bin-hadoop2.6\python\pyspark\context.py in     defaultParallelism(self)
  346         reduce tasks)
  347         """
  --> 348         return self._jsc.sc().defaultParallelism()
  349 
  350     @property

 AttributeError: 'NoneType' object has no attribute 'sc'

I am so fuzzed that i had created the "sc" in fact,why does it show the Error of"'NoneType' object has no attribute 'sc'"?

​

Solution

This should work (except in the code you have a missing ')' in the end of sc creation which I imagine is a type). You can try creating sc as follows:

conf = SparkConf().setAppName("app1").setMaster("local")
sc = SparkContext(conf=conf)

BTW sc.stop means you already have a spark context which is true if you used pyspark but not if you use spark-submit. It is better to use SparkContext.getOrCreate which works in both cases.