# David Kauchak
# 11/7/2011

def my_range(start, stop, step=1):
    """
    Return a list starting at start up to, but not including
    stop with increment step
    """
    i = start
    r = []
    
    while i < stop:
        r.append(i)
        i += step
    
    return r

def optional(val, adder=0, multiplier=1):
    """Multiply val by multiplier and add adder"""
    return val*multiplier + adder