title: What is the opposite of Union in Pyspark
body: <p>This seems like such a trivial question but I cannot find an answer anywhere! </p>
  
  <p>I have two RDDs, one with a vectorized article and another with a bunch of stopwords. My first instinct was to use the filter function but apparently you can't have two RDDs interact in that way. I know Union allows RDDs to interact but I need the exact opposite of that so I can filter out all of the stopwords in my first RDD. </p>
  
  <p>Any help would be much appreciated. </p>
  
  <p>EDIT: </p>
  
  <p><code>RDD1_filtered = RDD1.filter(lambda word: word not in RDD2)</code></p>
  
  <p>Both RDDs are a list of words. I get an error saying I cannot have two RDDs interacting</p>