Demo of grandfatherson Python library - Keeping 3 last days, 4 last weeks, and 3 months

degressive_upkeep

import datetime
import random
from grandfatherson import to_keep, to_delete, MONDAY
import pytz

# Install notes:
#   require grandfatherson & pytz - pip3 install grandfatherson pytz

utc=pytz.UTC
now = datetime.datetime.now().replace(tzinfo=utc) # ensure TZ aware

def gen_dates(range_days = 300, date_count = 100):
    dates_array = [now - datetime.timedelta(days=x, hours=random.randint(-24,24), minutes=random.randint(-60,60), seconds=random.randint(-60,60)) for x in range(date_count)]
    return sorted(dates_array)

def format_date(date):
    delta_with_now = now-date
    return date.strftime(f'%a %d/%m/%Y %H:%M:%S - Week %W - {delta_with_now.days} ago')

def print_dates(array):
    for date in array:
        print(format_date(date))


random_datetimes = gen_dates()

print("Today: ", format_date(now))
print()
print("All dates")
print_dates(random_datetimes)

print("All dates: ", len(random_datetimes))

dates_to_keep = sorted(to_keep(random_datetimes, days=3, weeks=4, months=3, firstweekday=MONDAY, now=now))
dates_to_delete = to_delete(random_datetimes, days=3, weeks=4, months=3, firstweekday=MONDAY, now=now)

print()
print("---")
print()
print("To keep:", len(dates_to_keep))
print_dates(dates_to_keep)

print("To delete: ", len(dates_to_delete))