Port of JavaScript Array.prototype.splice() to Python 3

list_splice.py

def list_splice(target, start, delete_count=None, *items):
    """Remove existing elements and/or add new elements to a list.

    target        the target list (will be changed)
    start         index of starting position
    delete_count  number of items to remove (default: len(target) - start)
    *items        items to insert at start index

    Returns a new list of removed items (or an empty list)
    """
    if delete_count == None:
        delete_count = len(target) - start

    # store removed range in a separate list and replace with *items
    total = start + delete_count
    removed = target[start:total]
    target[start:total] = items

    return removed

Updated the gist to remove the loop at the end (which called insert() for each of the *items). I just learned that slices can be assigned to which is a much better way to accomplish that same thing (line 17).

Thanks for this function! I advise replacing the delete_count == None for delete_count is None. That's the preferred way python checks for None.