How to find number of Mondays or any other weekday between two dates in Python?

Question

I have two dates between which I need to find out how many Mon- Fri are coming(except for Sta, Sun), everyday should be counted

Currently I am thinking this:

import calendar
import datetime
start_date = datetime.datetime.strptime("01/01/2017",'%d/%m/%Y')
end_date = datetime.datetime.strptime("31/01/2017",'%d/%m/%Y')
week_arr = [0] * 7
calendar.day_name[start_date.weekday()] ## will give me name of day
"""
As I receive Monday I will increment week_arr[0] by 1, Tuesday
week_arr[1]+= 1,
"""

I am not getting how to do it effectively so that I dont use much line of code(less if -else and for loops), may be some tricks in pandas.

Answer 1

You can define a function and use it like this :

def num_days_between( start, end, week_day):
    num_weeks, remainder = divmod( (end-start).days, 7)
    if ( week_day - start.weekday() ) % 7 < remainder:
       return num_weeks + 1
    else:
       return num_weeks

where week_day is day number you wan to calculate count.

Answer 2

Number of Mondays in 2020 can be got using numpy library

    import numpy as np
    np.busday_count('2020', '2021', weekmask='Mon')