Why spark tell me “ name 'sqlContext' is not defined ”, how can I use sqlContext?

Question

I try to run example of spark-ml, but

from pyspark import SparkContext
import pyspark.sql 

sc = SparkContext(appName="PythonStreamingQueueStream")    
training = sqlContext.createDataFrame([
(1.0, Vectors.dense([0.0, 1.1, 0.1])),
(0.0, Vectors.dense([2.0, 1.0, -1.0])),
(0.0, Vectors.dense([2.0, 1.3, 1.0])),
(1.0, Vectors.dense([0.0, 1.2, -0.5]))], ["label", "features"])

cannot run because terminal tells me that

NameError: name 'SQLContext' is not defined

Why this happened? How can I solve it?

Answer 1

If you are using Apache Spark 1.x line (i.e. prior to Apache Spark 2.0), to access the sqlContext, you would need to import the sqlContext; i.e.

from pyspark.sql import SQLContext
sqlContext = SQLContext(sc)

If you're using Apache Spark 2.0, you can just the Spark Session directly instead. Therefore your code will be

training = spark.createDataFrame(...)

For more information, please refer to the Spark SQL Programing Guide.