title: sc is not defined in SparkContext
body: <p>My Spark package is spark-2.2.0-bin-hadoop2.7.</p>
  
  <p>I exported spark variables as </p>
  
  <pre><code>export SPARK_HOME=/home/harry/spark-2.2.0-bin-hadoop2.7
  export PATH=$SPARK_HOME/bin:$PATH
  </code></pre>
  
  <p>I opened spark notebook by </p>
  
  <pre><code>pyspark
  </code></pre>
  
  <p>I am able to load packages from spark</p>
  
  <pre><code>from pyspark import SparkContext, SQLContext
  from pyspark.ml.regression import LinearRegression
  print(SQLContext)
  </code></pre>
  
  <p>output is </p>
  
  <pre><code>&lt;class 'pyspark.sql.context.SQLContext'&gt;
  </code></pre>
  
  <p>But my error is </p>
  
  <pre><code>print(sc)
  "sc is undefined"
  </code></pre>
  
  <p>plz can anyone help me out ...!</p>