title: How can I change SparkContext.sparkUser() setting (in pyspark)?
body: <p>I am new with <code>Spark</code> and <code>pyspark</code>.<br/>
  I use pyspark, after my <code>rdd</code> processing, I tried to save it to <code>hdfs</code> using the <code>saveAsTextfile()</code> function. 
  But I get a '<strong>permission denied</strong>' error message because pyspark tries to write <code>hdfs</code> 
  using my local account, 'kjlee', which does not exist on the <code>hdfs</code> system.</p>
  
  <p>I can check the spark user name by <code>SparkContext().sparkUser()</code>, But I can't find how to change the spark user name.</p>
  
  <p>How can I change the spark user name? </p>