Pythonで直近の前の金曜日の日付を調べる

last_friday.py

#!/usr/bin/env python

import datetime, calendar

def find_last_friday():
    
    # output: 2013-12-06
    last_friday = datetime.date.today()

    # output: 1 day, 0:00:00
    one_day = datetime.timedelta(days = 1)

    # calendar.FRIDAY: 4
    while last_friday.weekday() != calendar.FRIDAY:
        last_friday -= on_day

    return last_friday.strftime('%Y-%m-%d %A')

if __name__ == '__main__':
    print find_last_friday()