Calender.py

import datetime

# Set up the constants:
DAYS = ('Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday')
MONTHS = ('January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December')

print('Calendar Maker, by Shreyasi Das')

# Loop to get a year from the user.
while True:
    print('Enter the year for the calendar:')
    response = input('> ')
    if int(response) > 0:
        year = int(response)
        break
    print('Please enter a positive number, like 2023.')
    continue

# Loop to get a month from the user.
while True:
    print('Enter the month for the calendar, 1-12:')
    response = input('> ')
    month = int(response)
    if 1 <= month <= 12:
        break
    print('Please enter a number from 1 to 12.')
    continue


def getCalendarFor(year, month):
    calText = '' # calText will contain the string of our calendar.

    # Put the month and year at the top of the calendar:
    calText += (' ' * 34) + MONTHS[month - 1] + ' ' + str(year) + '\n'+('+----------' * 7) + '+\n'
    # Add the days of the week labels to the calendar

    calText += '|    SUN   |    MON   |    TUE   |    WED   |    THU   |    FRI   |    SAT   |\n'
    #calText += '|\t SUN \t|\t MON \t|\t TUE \t|\t WED \t|\t THU \t|\t FRI \t|\t SAT \t|\n'

    # The horizontal line string that separate weeks:
    weekSeparator = ('+----------' * 7) + '+\n'

    # The blank rows have ten spaces in between the | day separators:
    blankRow = ('|'+(' '*10))* 7 + '|\n'

   # Get the first date in the month. (The datetime module handles all the complicated calendar stuff for us here.)
    currentDate = datetime.date(year, month, 1)
    #print(f"currentDate is {currentDate}")


    # Roll back currentDate until it is Sunday. (weekday() returns 6 for Sunday, not 0.)
    while currentDate.weekday() != 6:
        currentDate -= datetime.timedelta(days=1)
        #print(f"currentDate is {currentDate}")

    while True: # Loop over each week in the month.
        calText += weekSeparator

        # dayNumberRow is the row with the day number labels:
        dayNumberRow = ''
        for i in range(7):
            dayNumberLabel = str(currentDate.day).rjust(2)
            dayNumberRow += '|' + dayNumberLabel + (' ' * 8)
            currentDate += datetime.timedelta(days=1) # Go to next day.
        dayNumberRow += '|' # Add the vertical line after Saturday.

        # Add the day number row and 3 blank rows to the calendar text.
        calText += dayNumberRow +'\n'

        for i in range(1): # (!) Try changing the 4 to a 5 or 10.
            calText += blankRow

        # Check if we're done with the month:
        if currentDate.month != month:
           break

    # Add the horizontal line at the very bottom of the calendar.
    calText += weekSeparator
    return calText

calText = getCalendarFor(year, month)
print(calText) # Display the calendar.

# Save the calendar to a text file:
calendarFilename = 'calendar_{}_{}.txt'.format(year, month)
with open(calendarFilename, 'w') as fileObj:
    fileObj.write(calText)

print('Saved to ' + calendarFilename)