title: Unpack list into middle of a tuple
body: <p>I have a list of uncertain size:</p>
  
  <pre><code>l = [...]
  </code></pre>
  
  <p>And I want to unpack this list into a tuple that has other values, but the below fails:</p>
  
  <pre><code>t = ("AA", "B", *l, "C")
  </code></pre>
  
  <p>How do I form the following?</p>
  
  <pre><code>t = ("AA", "B", l[0], ..., l[:-1], "C")
  </code></pre>
  
  <p>EDIT: it would also be nice to do a slice [a:b] only:</p>
  
  <pre><code>t = ("AA", "B", l[a], ..., l[b], "C")
  </code></pre>