title: ValueError: need more than 0 values to unpack(python lists)
body: <p>I'm getting an error while I'm writing my code</p>
  
  <pre><code>tmp = c.pop(0) # taking out the first element from the list as the starting point
  complete = tmp[0][-1]
  print(complete)
  
  while c != []:
      complete += tmp[1][-1]
      [index] = []
      for i, pair in enumerate(c):
          if pair[0] == tmp[1]:
              [index].append(i)
      temp = c.pop(index)
  
  print(complete)
  </code></pre>
  
  <p>I'm getting this error in the <code>[index] == []</code> part:</p>
  
  <pre><code>Traceback (most recent call last):
  ValueError: need more than 0 values to unpack
  </code></pre>
  
  <p>My question is, why is this error coming up and how should I fix this?</p>