Python | “万年历——日期查询”

from sys import *

Weeks = ['Sun', "Mon", 'Tus', 'Wed', 'Thu', 'Fri', 'Sat']   
    
try :
    date_in = argv[1]
except:
    print('\n ERROR! you forgot to enter the date you want to view\n')
    date_in = input("Please input a date!\n > ")
    
# print(date_in)
year, month, day = date_in.split('/')
try :
    year, month, day = int(year), int(month), int(day)
except :
    year = int(year)
    month = int(month)
    day = 0

if month < 1 or month > 12:
    print('\n ERROR! the entered MONTH is invalid\n')
    exit()

# 判断闰年，同时得到d用来计算日差，m2为闰月标记
if year > 2000:
    d = (year-1-2000)//4-(year-1-2000)//100+(year-1-2000)//400+1
elif year == 2000:
    dy = 0
    m2 = 1
else:
    d = (year-2000)//4-(year-2000)//100+(year-2000)//400

dy=(year-2000)+d
if (year%4==0 and year%100 != 0) or (year%100==0 and year%400==0):
    m2 = 1
else:
    m2 = 0

# 为精简代码行数，使用下面格式
# 判断每月天数
if month == 1 : dm = 0; month = 31
elif month == 2 : 
    dm = 3
    if d == 1 :
        month = 29
    else:
        month = 28
elif month == 3 : dm = 3 + m2; month = 31
elif month == 4 : dm = 6 + m2; month = 30
elif month == 5 : dm = 1 + m2; month = 31
elif month == 6 : dm = 4 + m2; month = 30
elif month == 7 : dm = 6 + m2; month = 31
elif month == 8 : dm = 2 + m2; month = 31
elif month == 9 : dm = 5 + m2; month = 30
elif month == 10 :dm = m2;   month = 31
elif month == 11 :dm = 3 + m2; month = 30
elif month == 12 :dm = 5 + m2; month = 31
else:
    print("What is it?")

if day < 0 or day > month :
    print("\n Error! The entered Day is invalid\n")
    exit()

# 判断该日期为星期几，若参数为月，则用来判断该月第一天为星期几
week = (dy + dm + day - 1 + 6) % 7

if week < 0 :
    week += 7

if day > 0:
    if week == 0:   WEEK = Weeks[0]
    elif week == 1:  WEEK = Weeks[1]
    elif week == 2:  WEEK = Weeks[2]
    elif week == 3:  WEEK = Weeks[3]
    elif week == 4:  WEEK = Weeks[4]
    elif week == 5:  WEEK = Weeks[5]
    elif week == 6:  WEEK = Weeks[6]
    else:
        pass
    print("\n this day is ", WEEK, "(",int(week),")"+ "\n OK!\n")
else:
    week = (week+1) % 7
    # 格式化输出
    print("\n the calender of this month as following")
    print("\n ***************************************")
    print(" SUN  MON  TUR  WEN  THU  FRI  STA\n")
    for i in range(int(week)):
        print("    ", end = ' ')
    for i in range(1, month+1):
        print(" %2d "%i, end = ' ')
        if (week+1) % 7 == 0 and i != month :
            print("\n")
        week = week + 1
    print("\n****************************************\n")
    print("\n OK! \n")

week = (dy + dm + day - 1 + 6) % 7
dy=(year-2000)+d
if year > 2000:
   d = (year-1-2000)//4-(year-1-2000)//100+(year-1-2000)//400+1
elif year == 2000:
   dy = 0
   m2 = 1
else:
   d = (year-2000)//4-(year-2000)//100+(year-2000)//400