python 日期、时间、字符串相互转换

（1）如果要比较，可以将dateTime转换为date，date不能直接转换为dateTime

import datetime dateTime_p = datetime.datetime.now() date_p = dateTime_p.date() print(dateTime_p) #2019-01-30 15:17:46.573139 print(date_p) #2019-01-30

（2）日期类型date转换为字符串str

#!/usr/bin/env python3 import datetime date_p = datetime.datetime.now().date() str_p = str(date_p) print(date_p,type(date_p)) #2019-01-30 <class \'datetime.date\'> print(str_p,type(str_p)) #2019-01-30 <class \'str\'>

（3）字符串类型str转换为dateTime类型

import datetime str_p = \'2019-01-30 15:29:08\' dateTime_p = datetime.datetime.strptime(str_p,\'%Y-%m-%d %H:%M:%S\') print(dateTime_p) # 2019-01-30 15:29:08

（4）dateTime类型转为str类型

　　这个地方我也不太理解，为什么指定格式无效

import datetime dateTime_p = datetime.datetime.now() str_p = datetime.datetime.strftime(dateTime_p,\'%Y-%m-%d\') print(dateTime_p) # 2019-01-30 15:36:19.415157

（5）字符串类型str转换为date类型

#!/usr/bin/env python3 import datetime str_p = \'2019-01-30\' date_p = datetime.datetime.strptime(str_p,\'%Y-%m-%d\').date() print(date_p,type(date_p)) # 2019-01-30 <class \'datetime.date\'>

另外dateTime类型和date类型可以直接做加1减1这种操作

#!/usr/bin/env python3 import datetime # today = datetime.datetime.today() today = datetime.datetime.today().date() yestoday = today + datetime.timedelta(days=-1) tomorrow = today + datetime.timedelta(days=1) print(today) # 2019-01-30 print(yestoday)# 2019-01-29 print(tomorrow)# 2019-01-31