Inclusive range (`irange`) using `range` as the basis

irange.py

def irange(*args):
    """irange(stop) -> range object
    irange(start, stop[, step]) -> range object
    
    Returns a range object that produces a sequence of integers from start (inclusive)
    to stop (also inclusive) by step, which defaults to 1
    
    irange(i, j) produces i, i+1, i+2, ..., j. (range would stop at j-1)
    start defaults to 0, and stop is omitted!  irange(4) produces 0, 1, 2, 3, 4.
    
    When step is given, it specifies the increment (or decrement)."""
    start, stop, step = None, None, None
    num_args = len(args)
    # Decides how to process the arguments
    match num_args:
        case 1: # just a stop value
            stop = args[0]
        case 2: # start and stop value
            start = args[0]
            stop = args[1]
        case 3: # start, stop, and step
            start = args[0]
            stop  = args[1]
            step = args[2]
        case _:
            raise ValueError("start, start and stop, or start, stop, and step values required.")
    
    if stop is not None and start is None:
        result = range(stop+1)
    if stop is not None and start is not None:
        if step is None:
            result = range(start, stop+1)
        else:
            if step > 0:
                result = range(start, stop+1, step)
            elif step < 0:
                result = range(start, stop-1, step)
            else:
                raise ValueError("step cannot be zero.")
    return result