workdays.py

import time
from datetime import datetime , timedelta
from dateutil.rrule import rrule, MONTHLY, DAILY

date_start_obj = datetime(2018,05,18)
date_end_obj = datetime(2018,05,30)
# holidays = [datetime(2018,05,21).date(), datetime(2018,05,28).date(), datetime(2018,05,20).date()]

def get_working_days(date_start_obj, date_end_obj, holidays=[]):
    many_holidays = 0
    span = date_end_obj - date_start_obj
    for i in xrange(span.days + 1):
        _date = date_start_obj + timedelta(days=i)
        if _date.date() in holidays and _date.weekday() in range(0, 5):
            print _date.date()
            many_holidays += 1
        
        
    weekdays = rrule(DAILY, byweekday=range(0, 5), dtstart=date_start_obj, until=date_end_obj)
    weekdays = len(list(weekdays))
    
    # desconsiderar do dia start 
    return (weekdays -1) - many_holidays 
  
  get_working_days(date_start_obj, date_end_obj, holidays)