def main():
 '''
 先用列表中每个数字代表每个人，然后通过循环替换列表中的数字
 用@代表基督徒，用__代表非基督徒
 '''
 people = [x for x in range(0,30)]
 people_ = [y for y in range(0,30)]
 i = 0
 j = 9
 while i<15 : 
  del people_[j]
  j += 9
  i += 1
  if j > len(people_):
   j = j - len(people_)
 for i in people_:
  for x in people:
   if i == x:
    people[people.index(x)] = '@'
 for j in range(30):
  if people[j] != '@':
   people[people.index(j)] = '__'
 print(people)
main()

import random
def generate_code(code_len=4):
 '''
 生成指定位数的验证码
 用code_len指定位数
 '''
 code = ''
 string = '1234567890qwertyuiopasdfghjklzxcvbnm'
 for _ in range(code_len):
  code += string[random.randint(0,26)]
 print(code)
 return code
 
generate_code()

def which_day(year,month,date):
 '''
 对应输入年份，月份，还有具体的日
 可以计算出这一日是这一年的第多少天
 year代表年，month代表月份，date代表具体日子
 '''
 day = 0
 for i in range(1,month + 1):
  if i < 9:
   if i % 2 == 0:
    day += 31
   else:
    day += 30
  else:
   if i % 2 == 0:
    day += 30
   else:
    day += 31
 if year % 4 == 0 and year % 100 != 0 or year % 400 == 0:
  day -= 1
 else:
  day -= 2
 print('您所求的这一天是那一年的第'+str(day)+'天')
which_day(1950,11,28)