subtract dates with time module

[barronmo]

Thanks for the help everyone.  I ended up with the following:

def OBweeks(ptID):
	qry = 'SELECT short_des FROM problems WHERE patient_ID = %s;' %
(ptID)
	results = EMR_utilities.getAllData(qry)
	for items in results:
	    r = re.search('\d\d\d\d-\d\d-\d\d', str(items))
	    if r:
		edc = datetime.date(*map(int, r.group().split('-')))
		pregnancy = datetime.timedelta(weeks=-40)
		conception = edc + pregnancy
		howfar = datetime.date.today() - conception
		weeks, days = divmod(howfar.days, 7)
		return '%s %s/7 weeks' % (weeks, days)
	    else: pass

Mike