title: Python Error: "ValueError: need more than 1 value to unpack"
body: <p>In Python, when I run this code:</p>
  
  <pre><code>from sys import argv
  
  script, user_name =argv
  prompt = '&gt;'
  
  print "Hi %s, I'm the %s script." % (user_name, script)
  </code></pre>
  
  <p>I get this error:</p>
  
  <pre><code>Traceback (most recent call last):  
  script, user_name =argv  
  ValueError: need more than 1 value to unpack
  </code></pre>
  
  <p>What does that error mean?</p>