Can someone help me with this Please

Question

(Day of the Week) Write a program called day_of_week.py that accepts m (int), d (int), and y (int) as command line arguments, representing a date, and writes the day of the week (0 for Sunday, 1 for Monday, and so on) dow to standard output, computed as

y0 = y − (14 − m) / 12

x = y0 + y0/4 − y0/100 + y0/400

m0 = m + 12 × ((14 − m) / 12) − 2

d0 = (d + x + 31m0 / 12) mod 7

Answer 1

I'm not quite sure what that algorithm you posted is, but there's an easier way! Dates and times are a pain to work with manually, so we can ask python to do most of the dirty work for us.

import sys

from datetime import datetime

if len(sys.argv) != 4:

print("Usage: script.py year month day")

sys.exit()

year = sys.argv[1]

month = sys.argv[2].zfill(2)

day = sys.argv[3].zfill(2)

# https://docs.python.org/3/library/datetime.html#datetime.date.weekday

a = datetime.fromisoformat('{}-{}-{}'.format(year, month, day))

print(a.weekday())

We use the sys module to extract command line arguments, and use the zfill() function to make sure that the dates always have a leading zero if less than 2 characters. So for example, "9" turns into "09", and "25" would remain the same since its already 2 characters long.

Finally, we leverage python's datetime module to use the fromisoformat() function, plugging in the year, month, and date respectively into the argument. So it would make something like "2022-09-26".

With a date, the fromisoformat() function then does all of the internal calculations for the date, and allows us to ask it for the weekday number, which we do in the final line.

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