In [8]: #!/usr/bin/env python
   ...: import dateutil.relativedelta as relativedelta
   ...: import dateutil.rrule as rrule
   ...: import datetime
   ...: year=2018
   ...: before=datetime.datetime(year,8,6)
   ...: after=datetime.datetime(year,11,16)
   ...: rr = rrule.rrule(rrule.WEEKLY,byweekday=relativedelta.FR,dtstart=before)
   ...:
   ...: d=rr.between(before,after,inc=True)
   ...:

In [9]: len(d)
Out[9]: 15