Yeah, that is kludgy (you're creating two lists now!).

First thing I would do is ask why I need that; I've never come across a case where I needed a pre-built list of items all initialized to a common or empty value - if you're doing that, I would explore some sort of custom generative process (building the items of your list as you need them). But, just because I can't think of a good use case for this (where I couldn't use generative recursion or iteration) doesn't mean you haven't. Weigh what you are doing.

I would do this one of two ways: create a function that will produce an object that will generatively build the list (like xrange, but pass an "initializer" value, like myxrange(0, 100, initialize=0)). See the source for Python's xrange to do this it should be quite easy.

Or do this in a while loop (flat, easy to understand, and you aren't being too naughty by producing more than once list):

    ls  = []
    cnt = 0
    
    while cnt <= 100:
      ls.append(0)
      cnt += 1
    

Alternatively you can do the above with a for loop but you would have to iterate over a sequence (which means creating a list to do it); the while loop is going to be the most efficacious way of doing what you want I think, excluding building a custom xrange style implementation.