pretty time formatting in python

gistfile1.py

def nice_time(delta):
    """
    Gets time delta in seconds and returns a pretty string
    representing it in the format of 1w2d9h16m44s
    """

    weeks = 0
    days = 0
    hours = 0
    minutes = 0
    seconds = 0

    seconds_in_minute = 60
    seconds_in_hour = 60 * seconds_in_minute
    seconds_in_day = 24 * seconds_in_hour
    seconds_in_week = 7 * seconds_in_day

    weeks = delta / seconds_in_week
    if weeks != 0:
        delta -= weeks * seconds_in_week

    days = delta / seconds_in_day
    if days != 0:
        delta -= days * seconds_in_day

    hours = delta / seconds_in_hour
    if hours != 0:
        delta -= hours * seconds_in_hour

    minutes = delta / seconds_in_minute
    if minutes != 0:
        delta -= minutes * seconds_in_minute

    seconds = delta

    out = ""
    if seconds:
        out = "%ss" % seconds + out
    if minutes:
        out = "%sm" % minutes + out
    if hours:
        out = "%sh" % hours + out
    if days:
        out = "%sd" % days + out
    if weeks:
        out = "%sw" % weeks + out

    if out == "":
        return "just now"
    return out