[homework] 2022.7.6 write your own cal function

stay linux of use vim Write calendar function , The basic functions are ：

1. Enter month and year , Output calendar
2. If you do not enter the month , But there are years , The output 1-12 Monthly calendar
3. If you do not enter , Then output the current calendar
4. If you enter month , But do not enter the year , It defaults to this year

vim own_cal.py

import datetime


def first_day(m, y):
    #  Calculate what is needed in the formula m, y, c 
    if m == 1 or m == 2:
        m += 12
        y -= 1
    
    c = y // 100
    y %= 100
    
    #  Calculate and return the day of the week on the first day of each month  
    return (y + y//4 + c//4 - 2 * c + 26 * (m+1) // 10) % 7


def total_days(m, y):
    #  Judgement of leap year 
    result = 1 if (y % 100 != 0 and y % 4 == 0) or (y % 400 == 0) else 0
    
    #  Judge the number of days 
    return 31 if m in [1, 3, 5, 7, 8, 10, 12] else (
        result + 28 if m == 2 else 30
    )


def get_cal(first_day, total_days): 
    #  establish cal list 
    cal = [' Japan ', ' One ', ' Two ', ' 3、 ... and ', ' Four ', ' 5、 ... and ', ' 6、 ... and ']
    
    #  Get the number of spaces in the first row of the calendar 
    for i in range(first_day):
        cal.append(' ')

    #  Get the remaining dates 
    for i in range(1, total_days + 1):
        cal.append(f'{
      i: <2}')

    return cal


def draw_cal(cal):
    #  Create count variables t
    t = 0

    for i in cal:
        # t yes 7 Line feed when multiple of , Other times spaces 
        print(f'\n{
      i}', end='') if t % 7 == 0 else print(f' {
      i}', end='')
        t += 1

    print('\n')


def cal_main(m, y):
    y = int(y)
    f_day = first_day(m, y)
    t_days = total_days(m, y)
    cal = get_cal(f_day, t_days)
    print(f'{
      y: >7} year {
      m:0>2} Monthly calendar ')
    draw_cal(cal)
    

if __name__ == '__main__':
    m = input(' Please enter the month : ')
    y = input(' Please enter the year : ')
    now_date = datetime.datetime.now()
    #  If the year and month are empty, the output is now ,  If only the month is empty, output 1-12 month 
    if m == '':
        if y == '':
            m_list = [now_date.month]
            y = now_date.year
        else:
            m_list = range(1, 13)
    else:
        m_list = [int(m)]

    for m in m_list:
        cal_main(m, y=now_date.year)

shift + :wq