A couple useful functions for dealing with python timedelta and human readable representations.

timetools.py

def str_to_timedelta(time_str):
    """Parses a human readable time duration string into a datetime.timedelta object
    
    Order from largest to smallest units. Numeric representation of values. Spaces
    optional. Specify units with first letter or full word (plural optional).
    Parses weeks, days, hours, minutes, seconds.
    
    Examples:
    -"1d5h42m33s"
    -"1 day 1 hours 43 seconds" (note that hour or hours is accepted here)
    -"8 minutes"
    -"8 weeks"
    
    """
    keys = ["weeks", "days", "hours", "minutes", "seconds"]
    regex = "".join(["((?P<%s>\d+)\s*(%s((%s)?s?))\s*)?" % (k, k[0], k[1:-1]) for k in keys])
    kwargs = {}
    for k,v in re.match(regex, time_str).groupdict(default="0").items():
        kwargs[k] = int(v)
    return timedelta(**kwargs)