python 缺失值处理

Python代码：

 
import datetime
 
def Date_interval_list(date_start = None,date_end = None):
 
if date_start is None:
 
　　date_start = '2000-01-01'
 
if date_end is None:
 
　　date_end = datetime.datetime.now().strftime('%Y-%m-%d')
 
 
date_start=datetime.datetime.strptime(date_start,'%Y-%m-%d')
 
date_end=datetime.datetime.strptime(date_end,'%Y-%m-%d')
 
date_list = []
 
date_list.append(date_start.strftime('%Y-%m-%d'))
 
while date_start < date_end:
 
date_start+=datetime.timedelta(days=+1)# 日期加一天
 
date_list.append(date_start.strftime('%Y-%m-%d'))# 日期存入列表
 
print(date_list)
 
 
 
if __name__ == '__main__':
 
Date_interval_list("2018-12-25", "2019-01-07")
运行结果：

 
['2018-12-25', '2018-12-26', '2018-12-27', '2018-12-28',
 
'2018-12-29', '2018-12-30', '2018-12-31', '2019-01-01',
 
'2019-01-02', '2019-01-03', '2019-01-04', '2019-01-05',
 
'2019-01-06', '2019-01-07']

---

MySQL代码： 

 
DELIMITER $$
 
DROP PROCEDURE IF EXISTS create_calendar $$
 
CREATE PROCEDURE create_calendar (s_date DATE, e_date DATE)
 
BEGIN
 
 
 
SET @createSql = 'CREATE TABLE IF NOT EXISTS calendar (
 
`date` date NOT NULL,
 
UNIQUE KEY `unique_date` (`date`) USING BTREE
 
)ENGINE=InnoDB DEFAULT CHARSET=utf8';
 
prepare stmt from @createSql;
 
execute stmt;
 
 
 
WHILE s_date <= e_date DO
 
INSERT IGNORE INTO calendar VALUES (DATE(s_date)) ;
 
SET s_date = s_date + INTERVAL 1 DAY ;
 
END WHILE ;
 
 
 
END$$
 
DELIMITER ;
 
 
 
CALL create_calendar ('2018-12-25', '2019-01-07');
 
 

 运行结果：

MySQL的运行结果是直接生成一张表calendar，表中包含日期间隔里的所有日期date。