How to generate k+1 length strings from a list of k length strings?

[Boris Borcic]

> Hum, since your code is not syntactically correct, anything will run 
> faster :)

in fact it parses, I was fooled by this line

>>         if k in range(1,len(prunedK),1) & i+k <= len(prunedK) -1:


I was fooled because the form "k in range(" tends to imply a for statement ;
  in the case of an if statement, one usually uses chained comparisons instead.

If you know i>=0 and i,k are integers (as is implied by context), you could 
simply write something like:

            if 0 < k < i+k < len(prunedK) :


in the contrary case,
assuming your line does what you want, you should really write it as

            if 1 <= k < len(prunedK) and i+k <= len(prunedK)-1 :

or more concisely

            if 1 <= k < len(prunedK) >= i+k+1 :

or even

            if i+k < len(prunedK) > k > 0 :