title: pyspark: pip install couldn't find a version
body: <p>I am trying to install the <code>pyspark</code> using <code>pip install</code> like below. But I got the following errors.</p>
  
  <pre><code>(python_virenv)edamame$ pip install pyspark
  Collecting pyspark
    Could not find a version that satisfies the requirement pyspark (from versions: )
  No matching distribution found for pyspark
  </code></pre>
  
  <p>Does anyone have any idea? Thanks!</p>