title: list extend() to index, inserting list elements not only to the end
body: <p>I'm looking for the most pythonic way to implement a version of the list <code>extend</code> function, where it extends to a given index instead of the end of the list.</p>
  
  <pre><code>a_list = [ "I", "rad", "list" ]                                                       
  b_list = [ "am", "a" ]
  a_list.my_extend( b_list, 1 ) # insert the items from b_list into a_list at index 1
  
  print( a_list ) # would output: ['I', 'am', 'a', 'rad', 'list']
  </code></pre>
  
  <p>Is there a way to do this without building a new list, like this?</p>
  
  <pre><code>a_list = [ "I", "rad", "list" ]
  b_list = [ "am", "a" ]
  c_list = []
  
  c_list.extend( a_list[:1] )
  c_list.extend( b_list     )
  c_list.extend( a_list[1:] )
  
  print( c_list ) # outputs: ['I', 'am', 'a', 'rad', 'list']
  </code></pre>
  
  <p>That approach isn't actually so bad, but I have a hunch it could be easier.  Could it?</p>