如何在Linux shell脚本或python中找出上周六的日期？

Question

I have python script which i need to run daily for backups. Now i need to find the date of last saturday because i need that in my script to get the backups i did on last saturdy. Suppose

on saturday i made this file

weekly_user1_Jul-13-2013.sql

I ned to get that name in script which i run daily. so for script running on saturday i need to get todays date , buif its on sunday then i need to get last saturday date.

how can i do that

Answer 1

$ date +"%b-%d-%Y" -d "last saturday"
Jul-13-2013

Answer 2

In python script:

from datetime import date
from datetime import timedelta
today = date.today()
last_saturday = today - timedelta(days= (today.weekday() - 5) % 7)

Answer 3

On Mac OS it would be:

$ date -v -sat +"%b-%d-%Y"
Mar-28-2015