title: Return an RDD from takeOrdered, instead of a list
body: <p>I'm using pyspark to do some data cleaning. A very common operation is to take a small-ish subset of a file and export it for inspection:</p>
  
  <pre><code>(self.spark_context.textFile(old_filepath+filename)
      .takeOrdered(100) 
      .saveAsTextFile(new_filepath+filename))
  </code></pre>
  
  <p>My problem is that takeOrdered is returning a list instead of an RDD, so saveAsTextFile doesn't work.</p>
  
  <pre><code>AttributeError: 'list' object has no attribute 'saveAsTextFile'
  </code></pre>
  
  <p>Of course, I could implement my own file writer. Or I could convert the list back into an RDD with parallelize. But I'm trying to be a spark purist here. </p>
  
  <p>Isn't there any way to return an RDD from takeOrdered or an equivalent function?</p>